Psychosis
Psychosis is a psychiatric classification for a mental state in which the perception of reality is distorted. Persons experiencing a psychotic episode may experience hallucinations (often auditory or visual hallucinations), hold paranoid or delusional beliefs, experience personality changes and exhibit disorganized thinking (see thought disorder). This is sometimes accompanied by a lack of insight into the unusual or bizarre nature of their behaviour and an inability to cope in society.
Overview
Psychosis is usually considered by mainstream psychiatry to be a symptom of severe mental illness, such as schizophrenia or bipolar disorder (manic depression). It may also occur in severe cases of depression, brain injury or drug overdose. Chronic psychological stress cultures psychotic states, however the exact neurological mechanism is uncertain. Psychosis triggered by stress in the absence of any other mental illness is known as brief reactive psychosis. The direct effects of hallucinogenic drugs are not usually classified as psychosis, as long as they abate when the drug is metabolised from the body.
Psychosis is a descriptive term for a complex group of behaviours and experiences and as such is not a medical explanation in itself. Perhaps because of this, it is often confused with syndromes which may seem similar on the surface, or with words which may suggest, or seem to suggest a likeness.
The term psychosis should be distinguished from the concept of insanity, which is a legal term denoting that a person should not be criminally responsible for his actions. Similarly, it should be distinguished from psychopathy, a personality disorder often associated with violence, lack of empathy and socially manipulative behaviour. Despite the fact that both are colloquially abbreviated to 'psycho', psychosis bears little similarity to psychopathy's core features, particularly with regard to violence, which rarely occurs in psychosis, and the distortion of perceived reality, which rarely occurs in psychopathy.
It should also be distinguished from the state of delirium, in that a psychotic individual may be able to perform actions that require a high level of intellectual effort in clear consciousness. Finally, it should be distinguished from mental illness. Psychosis may be regarded as a symptom of other mental illnesses, but as a descriptive concept it is not considered an illness in its own right. For example, persons with schizophrenia can have long periods without psychosis and persons with bipolar disorder and depression can have mood symptoms without psychosis. Conversely, psychosis can occur in persons without chronic mental illness as a result of an adverse drug reaction or extreme stress.
Psychosis has been of particular interest to critics of mainstream psychiatric practice who argue that it may simply be another way of constructing reality and is not necessarily a sign of illness. For example, R. D. Laing has argued that psychosis is a symbolic way of expressing concerns in situations where such views may be unwelcome or uncomfortable to the recipients. Thomas Szasz has focused on the social implications of labelling people as psychotic, a label which he argues unjustly medicalises different views of reality so such unorthodox people can be controlled by society.
Etymology: The word psychosis was first used by Ernst von Feuchtersleben in 1845 as an alternative to insanity and mania and stems from the Greek psykhe (mind) and osis (diseased or abnormal condition). The word was used to distinguish disorders which were thought to be disorders of the mind, as opposed to neurosis, which was thought to stem from a disorder of the nerves.
Psychotic experience
A psychotic episode can be significantly coloured by mood. For example, people experiencing a psychotic episode in the context of depression may experience persecutory or self-blaming delusions or hallucinations, whilst people experiencing a psychotic episode in the context of mania may form grandiose delusions or have an experience of deep religious significance.
Although usually distressing and regarded as an illness process, some people who experience psychosis find beneficial aspects and value the experience or revelations that stem from it.
Hallucinations in psychosis
Hallucinations are defined as sensory perception in the absence of external stimuli. Psychotic hallucinations may occur in any of the five senses and take on almost any form, which may include simple sensations (such as lights, colours, tastes, smells) to more meaningful experiences such as seeing and interacting with fully formed animals and people, hearing voices and complex tactile sensations.
Auditory hallucinations, particularly the experience of hearing voices, is a common and often prominent feature of psychosis. Hallucinated voices may talk about, or to the person, and may involve several speakers with distinct personas. Auditory hallucinations tend to be particularly distressing when they are derogatory, commanding or preoccupying.
Delusions and paranoia
Psychosis may involve delusional or paranoid beliefs. Karl Jaspers classified psychotic delusions into primary and secondary types. Primary delusions are defined as arising out-of-the-blue and not being comprehensible in terms of normal mental processes, whereas secondary delusions may be understood as being influenced by the person's background or current situation.
Thought disorder
Thought disorder describes an underlying disturbance to conscious thought and is classified largely by its effects on speech and writing. Affected persons may show pressure of speech (speaking incessantly and quickly), derailment or flight of ideas (switching topic mid-sentence or inappropriately), thought blocking, rhyming or punning.
Lack of insight
One important and puzzling feature of psychosis is usually an accompanying lack of insight into the unusual, strange or bizarre nature of the person's experience or behaviour. Even in the case of an acute psychosis, the sufferer may seem completely unaware that their vivid hallucinations and impossible delusions are in any way unrealistic. This is not an absolute, however; insight can vary between individuals and throughout the duration of the psychotic episode.
In some cases, particularly with auditory and visual hallucinations, the patient has good insight and this makes the psychotic experience even more terrifying in that the patient realizes that he should not be seeing demons and angels or hearing voices, but does.
Medical understanding of psychosis
There are a number of possible causes for psychosis. Psychosis may be the result of an underlying mental illness such as Bipolar disorder (also known as manic depression), and schizophrenia. Psychosis may also be triggered or exacerbated by severe mental stress and high doses or chronic use of drugs such as amphetamines, LSD, PCP, cocaine or scopolamine. However, incidence of psychosis resulting from a single administration of any drug is rare, although cases have been reported in the medical literature suggesting a person's sensitivities to new compounds can be unpredictable. As can been seen from the wide variety of illness and conditions in which psychosis has been reported to arise (including for example, AIDS, leprosy, malaria and even mumps) there is no singular cause of a psychotic episode.
The division of the major psychoses into manic depression and dementia praecox (later renamed to schizophrenia) was made by Emil Kraepelin, who attempted to create a synthesis of the various mental disorders identified by 19th century psychiatrists, by grouping diseases together based on classification of common symptoms. Kraeplin used the term 'manic depression' to describe the whole spectrum of mood disorders, in a far wider sense than it is usually used today. In Krapelin's classification this would include 'unipolar' clinical depression, as well as bipolar disorder and other mood disorders such as cyclothymia. These are characterised by problems with mood control and the psychotic episodes appear associated with disturbances in mood, and patients will often have periods of normal functioning between psychotic episodes even without medication. Schizophrenia is characterized by psychotic episodes which appear to be unrelated to disturbances in mood, and most non-medicated patients will show signs of disturbance between psychotic episodes.
Psychotic episodes may vary in duration between individuals. In brief reactive psychosis, the psychotic episode is related directly to a specific stressful life event so patients may spontaneously recover normal functioning within two weeks. Patients who are undergoing brief reactive psychosis due to drugs or stress generally appear with the same symptoms as a person who is psychotic as a result of a mental illness, and this fact has been used to support the notion that mental illness has a biological basis.
Psychosis and brain function
The first brain image of person with psychosis was completed as far back as 1935 using a technique called pneumoencephalography1 (a painful and now obsolete procedure where cerebrospinal fluid is drained from around the brain and replaced with air to allow the structure of the brain to show up more clearly on an X-ray picture).
Pneumoencephalogram of person with psychosis, 1935Modern brain imaging studies, investigating both changes in brain structure and changes in brain function of people undergoing psychotic episodes have shown mixed results.
A 2003 study investigating structural changes in the brains of people with psychosis showed there was significant grey matter reduction in the cortex of people before and after they became psychotic2. Findings such as these have led to debate about whether psychosis is itself neurotoxic and whether potentially damaging changes to the brain are related to the length of psychotic episode. Recent research has suggested that this is not the case3 although further investigation is still ongoing.
Functional brain scans have revealed that the areas of the brain that reacts to sensory perceptions are active during psychosis. For example, a PET or fMRI scan of a person who claims to be hearing voices may show activation in the auditory cortex, or parts of the brain involved in the perception and understanding of speech.
On the other hand, there is not a clear enough psychological definition of belief to make a comparison between different people particularly valid. Brain imaging studies on delusions have typically relied on correlations brain activation patterns with the presence of delusional beliefs.
One clear finding is that persons with a tendency to have psychotic experiences seem to show increased activation in the right hemisphere of the brain4. This increased level of right hemisphere activation has also been found in healthy people who have high levels of paranormal beliefs5 or in people who report mystical experiences6. It also seems to be the case that people who are more creative are also more likely to show a similar pattern of brain activation7. Some researchers have been quick point out that this in no way suggests that paranormal, mystical or creative experiences are in any way by themselves a symptom of mental illness, as it is still not clear what makes some such experiences beneficial whilst others lead to the impairment or distress of diagnosable mental pathology. However, people who have profoundly different experiences of reality or hold unusual views or opinions have traditonally held a complex role in society, with some being viewed as kooks, whilst others are lauded as prophets or visionaries.
Psychosis has been traditionally linked to the neurotransmitter dopamine, particularly an excess of dopamine in the limbic system (a structure deep within the brain). The development of effective antipsychotic medication played a large part in the success of this view, as the first effective antipsychotic drugs were dopamine blockers. In addition, drugs that increase the concentration of dopamine tend to trigger psychotic episodes.
Nevertheless, the connection between dopamine and psychosis is generally believed to be complex. First of all, while anti-psychotic drugs immediately block dopamine receptors, they usually take a week or two to reduce the symptoms of psychosis. Moreover, newer and equally as effective antipsychotic drugs actually block slightly less dopamine in the brain than older drugs whilst also affecting serotonin levels, suggesting the 'dopamine hypothesis' is vastly oversimplified. Psychiatrist David Healy has criticised pharmaceutical companies for promoting particular scientific theories that favour their medication and encouraging a purely biological account of mental illness8, whilst ignoring social and developmental factors which are known to be important influences in the aetiology of psychosis. See the article on the dopamine hypothesis of psychosis for further discussion of this issue.
Some theories regard many psychotic symptoms to be a problem with the perception of ownership of internally generated thoughts and experiences9. For example, the experience of hearing voices may arise from internally generated speech that is mislabelled by the psychotic person as coming from an external source.
It has also been argued that psychosis exists on a continuum as everybody may have some unusual and potentially reality-distorting experiences in their life. This has been backed up by research showing that experiences such as hallucinations have been experienced by large numbers of the population who may never be impaired or even distressed by their experiences10. In this view, people who are diagnosed with a psychotic illness may simply be one end of a spectrum where the experiences become particularly intense or distressing (see schizotypy).
Cannabis and psychosis
There is now growing evidence for a small but significant link between cannabis use and vulnerability to psychosis11. Some studies indicate that cannabis use correlates with a slight increase in psychotic experience, which may trigger full-blown psychosis in some people. Early studies have been criticized for failing to consider other drugs (such as LSD) that the subjects may also have used before or during the study, as well as other factors such as possible pre-existing mental health issues. However, more recent studies with better control have still found a small increase in risk for psychosis in cannabis users. It is still not clear whether this is a causal link, and it may be that cannabis use only increases the chance of psychosis in people already predisposed to it. The fact that cannabis use has increased over the past few decades, whereas the rate of psychosis has not, suggests that a direct causal link is unlikely for all users.
Non-psychiatric conditions and psychosis
Psychosis can be a feature of several diseases, often when the brain or nervous system is directly affected. However, the fact that psychosis can occasionally arise in parallel with number of ailments (including diseases such as flu or mumps for example) suggests that a variety of nervous system stressors can lead to a psychotic reaction. Psychosis arising from non-psychiatric conditions is sometimes known as 'secondary psychosis'. The mechanisms by which this happens is still not clear, but the non-specificity of psychosis has led Tsuang and colleagues to argue that "psychosis is the 'fever' of mental illness - a serious but nonspecific indicator"12.
There are some non-psychiatric conditions which are linked particularly to psychosis, which may include:
· Systemic Lupus Erythematosus (it is one of the 19 types of nervous system involvement in SLE).
· Sarcoidosis
· Brain tumours
· dementia with Lewy bodies
· Multiple sclerosis
· hypoglycemia
· intoxication
Formal thought disorder
In psychiatry, thought disorder or formal thought disorder is a term used to describe a symptom of psychotic mental illness.
It describes a persistent underlying disturbance to conscious thought and is classified largely by its effects on speech and writing. Affected persons may show pressure of speech (speaking incessantly and quickly), derailment or flight of ideas (switching topic mid-sentence or inappropriately), thought blocking, rhyming or punning or 'word salad' when individual words may be intact but speech is incoherent.
Subtypes in detail
Pressure of speech : An increase in the amount of spontaneous speech compared to what is considered customary.
Distractible speech : During mid speech, the subject is changed in response to a stimulus. e.g. "Then I left San Francisco and moved to... where did you get that tie ?"
Tangentiality : Replying to questions in an oblique, tangential or irrelevant manner. e.g. "What city are you from ?", "Well, that's a hard question. I'm from Iowa. I really don't know where my relatives came from, so I don't know if I'm Irish or French".
Derailment : Ideas slip off the track on to another which is obliquely related or unrelated. e.g. "The next day when I'd be going out you know, I took control, like uh, I put bleach on my hair in California".
Incoherence (word salad) : Speech that is unintelligible due to the fact that, though the individual words are real words, the manner in which they are strung together results in incoherent gibberish, e.g. the question "Why do people believe in God?" elicits a response like "Because make a twirl in life, my box is broken help me blue elephant. Isn't lettuce brave? I like electrons, hello."
Illogicality : Conclusions are reached that do not follow logically (non sequiturs or faulty inductive inferences).
Clanging : Sounds rather than meaningful relationships appear to govern words. e.g. "I'm not trying to make noise. I'm trying to make sense. If you can't make sense out of nonsense, well, have fun".
Neologisms : New word formations. e.g. "I got so angry I picked up a dish and threw it at the geshinker".
Word approximations : Old words used in a new and unconventional way. e.g. "His boss was a seeover".
Circumstantiality : Speech that is very delayed at reaching its goal. Excessive long windedness.
Loss of goal : Failure to show a chain of thought to a natural conclusion.
Perseveraton : Persistent repetition of words or ideas. e.g. "I'll think I'll put on my hat, my hat, my hat, my hat, my hat, my hat, my hat, my hat..."
Echolalia : Echoing of other people's speech e.g. "Can we talk for a few minutes ?", "Talk for a few minutes".
Blocking : Interruption of train of speech before completed.
Stilted speech : Speech excessively stilted and formal. e.g. "The attorney comported himself indecorously".
Self-reference : Patient repeatedly and inappropriately refers back to self. e.g. "What's the time?", "It's 7 o'clock. That's my problem".
Phonemic paraphasia : Mispronounciation; syllables out of sequence. e.g. "I slipped on the lice broke my arm".
Semantic paraphasia : Substitution of inappropriate word. e.g. "I slipped on the coat, on the ice I mean, and broke my book".
Diagnostic issues
The concept of thought disorder has been criticized as being based on circular or incoherent definitions. For example, thought disorder is inferred from disordered speech, however it is assumed that disordered speech arises because of disordered thought. Similarly the definition of 'Incoherence' (word salad) is that speech is incoherent.
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Schizophrenia
Schizophrenia is a psychiatric diagnosis denoting a persistent, often chronic, mental illness variously affecting behaviour, thinking, and emotion. The term schizophrenia comes from the Greek words (schizo, split or divide) and (phrenos, mind) and is best translated "shattered mind".
Introduction
Schizophrenia is most commonly characterised by both 'positive symptoms' (those additional to normal experience and behaviour) and negative symptoms (the lack or decline in normal experience or behaviour). Positive symptoms are grouped under the umbrella term psychosis and typically include delusions, hallucinations, and thought disorder. Negative symptoms may include inappropriate or lack of emotion, poverty of speech, and lack of motivation. Additionally, neurocognitive deficits may be present. These take the form of reduction or impairment in basic psychological functions such as memory, attention, problem solving, and social cognition. The onset is typically in late adolescence and early adulthood, with males tending to show symptoms earlier than females.
Psychiatrist Emil Kraepelin was first to make the distinction between what he called dementia praecox and other forms of madness. This classification was later renamed 'schizophrenia' by psychiatrist Eugene Bleuler as it became clear Kraepelin's name was not an adequate description of the condition.
The diagnostic approach to schizophrenia has been opposed, most notably by the anti-psychiatry movement, who argue that classifying specific thoughts and behaviours as illness allows social control of people that society finds undesirable but who have committed no crime.
More recently, it has been argued that schizophrenia is just one end of a spectrum of experience and behaviour, and everybody in society may have some such experiences in their life. This is known as the 'continuum model of psychosis' or the 'dimensional approach' and is most notably argued for by psychologist Richard Bentall and psychiatrist Jim van Os.
Although no definite causes of schizophrenia have been identified, most researchers and clinicians currently believe that schizophrenia is primarily a disorder of the brain. It is thought that schizophrenia may result from a mixture of genetic disposition (genetic studies using various techniques have shown relatives of people with schizophrenia are more likely to show signs of schizophrenia themselves) and environmental stress (research suggests that stressful life events may precede a schizophrenic episode).
It is also thought that processes in early neurodevelopment are important, particularly those that occur during pregnancy. In adult life, particular importance has been placed upon the function (or malfunction) of dopamine in the mesolimbic pathway in the brain. This theory, known as the dopamine hypothesis of schizophrenia largely resulted from the accidental finding that a drug group which blocks dopamine function, known as the phenothiazines, reduced psychotic symptoms. These drugs have now been developed further and antipsychotic medication is commonly used as a first line treatment. However, this theory is now thought to be overly simplistic as a complete explanation.
History
Accounts that may relate to symptoms of schizophrenia date back as far as 2000 BC in Book of Hearts, a part of the ancient Ebers papyrus. However, a recent study1 into the ancient Greek and Roman literature showed that whilst the general population probably had an awareness of psychotic disorders, there was no condition that would meet the modern diagnostic criteria for schizophrenia in these societies.
This nonspecific concept of madness has been around for many thousands of years and schizophrenia was only classified as a distinct mental disorder by Kraepelin in 1887. He was the first to make a distinction in the psychotic disorders between what he called dementia praecox (a term first used by psychiatrist Benedict A. Morel) and manic depression. Kraepelin believed that dementia praecox was primarily a disease of the brain2, and particularly a form of dementia. Kraepelin named the disorder 'dementia praecox' (early dementia) to distinguish it from other forms of dementia (such as Alzheimer's disease) which typically occur late in life. He used this term because his studies focused on young adults with dementia.
The term schizophrenia is derived from the Greek words 'schizo' (split) and 'phrene' (mind) and was coined by Eugene Bleuler to refer to the lack of interaction between thought processes and perception. He was also the first to describe the symptoms as "positive" or "negative."22 Bleuler changed the name to schizophrenia as it was obvious that Krapelin's name was misleading. The word "praecox" implied precocious or early onset, hence premature dementia, as opposed to senile dementia from old age. Bleuler realised the illness was not a dementia (it did not always lead to mental deterioration) and could sometimes occur late as well as early in life and was therefore misnamed.
With the name 'schizophrenia' Bleuler intended the name to capture the separation of function between personality, thinking, memory, and perception, however it is commonly misunderstood to mean that affected persons have a 'split personality' (something akin to the character in Robert Louis Stevenson's The Strange Case of Dr. Jekyll and Mr. Hyde). Although it is commonly confused with multiple personality disorder, schizophrenia has nothing to do with the manifestation of distinct multiple personalities within a person. The confusion perhaps arises in part due to the meaning of Blueler's term 'schizophrenia'. Interestingly, the first known misuse of this term to mean 'split personality' (in the Jekyll and Hyde sense) was in an article by the poet T. S. Eliot in 19333.
Incidence and prevalence
Schizophrenia is typically diagnosed in late adolescence or early adulthood. It is found approximately equally in men and women, though the onset tends to be later in women, who also tend to have a better course and outcome.
The lifetime prevalence of schizophrenia is commonly given at 1%, however a recent review of studies from around the world estimated it to be 0.55%14. The same study also found that prevalence may vary greatly from country to country, despite the received wisdom that schizophrenia occurs at the same rate throughout the world. It is worth noting however, that this may be in part due to differences in the way schizophrenia is diagnosed. The incidence of schizophrenia was given as a range of between 7.5 and 16.3 cases per 100,000 of the population.
Schizophrenia is also a major cause of disability. In a recent 14-country study15, active psychosis was ranked the third most disabling condition after quadriplegia and dementia and before paraplegia and blindness.
Cause
While the reliability of the schizophrenia diagnosis introduces difficulties in measuring the relative effect of genes and environment (for example, symptoms overlap to some extent with severe bipolar disorder or major depression), there is evidence to suggest that genetic vulnerability modified by environmental stressors can act in combination to cause schizophrenia.
A recent review listed seven genes as likely to be involved in the inheritance of schizophrenia or the risk of developing schizophrenia26. Evidence comes from research (such as linkage studies) suggesting multiple chromosomal regions are transmitted to people who are later diagnosed as having schizophrenia. Some family association studies have demonstrated a relationship to a gene known as COMT that is involved in encoding the dopamine catabolic enzyme catechol-O-methyl transferase27. This is particularly interesting because of the known link between dopamine function, psychosis, and schizophrenia.
While highly heritable (close to 70%), schizophrenia is a disorder of complex inheritance (analogous to diabetes or high blood pressure). Thus, several genes interact to generate risk for schizophrenia. Genetic evidence for the role of the environment comes from the observation that identical twins do not universally develop schizophrenia. A recent review of the genetic evidence have suggested a 28% chance of one identical twin developing schizophrenia if the other already has it7.
There is also considerable evidence indicating that stress may trigger episodes of schizophrenia. For example, emotionally turbulent families8 and stressful life events9 have been shown to be risk factors for relapses or triggers for episodes of schizophrenia. Other factors such as poverty and discrimination may also be involved. This may explain why minority communities have much higher rates of schizophrenia than when members of the same ethnic groups are resident in their home country.
One particularly stable and replicable finding has been the association between living in an urban environment and risk of developing schizophrenia, even after factors such as drug use, ethnic group and size of social group have been controlled for29. A recent study of 4.4 million men and women in Sweden found a 68-77% increased risk of psychosis for people living in the most urbanised environments, a significant proportion of which is likely to be accounted for by schizophrenia30.
In addition to the risk factors listed above, researchers have curiously found that those suffering from schizophrenia are much more likely to have been born during the Winter months, particularly February and March. Researchers studying manic-depressive disorder have also found that this phenomenon applies to their patients as well.
Although no definite causes of schizophrenia have been identified, most researchers and clinicians currently believe that schizophrenia is primarily a disorder of the brain.
It is also thought that processes in early neurodevelopment are important, particularly during pregnancy. For example, women who were pregnant during the Dutch famine of 1944, where many people were close to starvation, had a higher chance of having a child who would later develop schizophrenia10. Similarly, studies of Finnish mothers who were pregnant when they found out that their husbands had been killed during the Winter War of 1939 - 1940 have shown that their children were much more likely to develop schizophrenia when compared with mothers who were found out about their husbands' death before or after pregnancy11, suggesting that even psychological trauma in the mother may have an effect.
In adult life, particular importance has been placed upon the function (or malfunction) of dopamine in the mesolimbic pathway in the brain. This theory, known as the dopamine hypothesis of schizophrenia largely resulted from the accidental finding that a drug group which blocks dopamine function, known as the phenothiazines, reduced psychotic symptoms. These drugs have now been developed further and antipsychotic medication is commonly used as a first line treatment.
However, this theory is now thought to be overly simplistic as a complete explanation. Partly as newer antipsychotic medication (called atypical antipsychotic medication) is equally effective as older medication, but also affects serotonin function and may have slightly less of a dopamine blocking effect. Psychiatrist David Healy has also argued that pharmaceutical companies have promoted certain oversimplified biological theories of mental illness to promote their own sales of biological treatments.
Much recent research has focused on differences in function in certain brain areas in people diagnosed with schizophrenia. Studies using neuropsychological tests and brain scanning technologies such as fMRI and PET have shown that differences seem to most commonly occur in the frontal lobes, hippocampus, and temporal lobes13. These differences are heavily linked to the neurocognitive deficits which often occur with schizophrenia, particularly in areas of memory, attention, problem solving, and social cognition.
Diagnosis and presentation (signs and symptoms)
Like many mental illnesses, the diagnosis of schizophrenia is based upon the behaviour of the person being assessed. There is a list of diagnostic criteria which must be met for a person to be so diagnosed. These depend on both the presence and duration of certain signs and symptoms.
The most commonly-used criteria for diagnosing schizophrenia are from the American Psychiatric Association's Diagnostic and Statistical Manual of Mental Disorders (DSM) and the World Health Organisation's International Statistical Classification of Diseases and Related Health Problems (ICD). The most recent versions are ICD-10 (
http://www.who.int/whosis/icd10/) and DSM-IV-TR (
http://www.psych.org/research/dor/dsm/index.cfm).
Below is an abbreviated version of the diagnostic criteria from the DSM-IV-TR, the full version is available here (
http://www.behavenet.com/capsules/disorders/schiz.htm).
To be diagnosed as having schizophrenia, a person must display:
A) Characteristic symptoms: Two or more of the following, each present for a significant portion of time during a one-month period (or less, if successfully treated)
. delusions
· hallucinations
· disorganized speech (e.g., frequent derailment or incoherence). See thought disorder.
· grossly disorganized or catatonic behavior
· negative symptoms, i.e., affective flattening (lack or decline in emotional response), alogia (lack or decline in speech), or avolition (lack or decline in motivation).
Note: Only one Criterion A symptom is required if delusions are bizarre or hallucinations consist of hearing voices.
B) Social/occupational dysfunction: For a significant portion of the time since the onset of the disturbance, one or more major areas of functioning such as work, interpersonal relations, or self-care, are markedly below the level achieved prior to the onset.
C) Duration: Continuous signs of the disturbance persist for at least six months. This six-month period must include at least one month of symptoms (or less, if successfully treated) that meet Criterion A.
Historically, schizophrenia in the West was classified into simple, catatonic, hebephrenic, and paranoid. The DSM now contains five sub-classifications of schizophrenia. These are
· catatonic type (where marked absences or peculiarities of movement are present),
· disorganised type (where thought disorder and flat or inappropriate affect are present together),
· paranoid type (where delusions and hallucinations are present but thought disorder, disorganised behaviour, and affective flattening is absent),
· residual type (where positive symptoms are present at a low intensity only) and
· undifferentiated type (psychotic symptoms are present but the criteria for paranoid, disorganized, or catatonic types has not been met).
Symptoms may also be described as 'positive symptoms' (those additional to normal experience and behaviour) and negative symptoms (the lack or decline in normal experience or behaviour). 'Positive symptoms' describe psychosis and typically include delusions, hallucinations and thought disorder. 'Negative symptoms' describe inappropriate or nonpresent emotion, poverty of speech, and lack of motivation.
It is worth noting that many of the positive or psychotic symptoms may occur in a variety of disorders and not only in schizophrenia. The psychiatrist Kurt Schneider tried to list the particular forms of psychotic symptoms which he thought were particularly useful in distinguishing between schizophrenia and other disorders which could produce psychosis. These are called first rank symptoms or Schneiderian first rank symptoms and include delusions of being controlled by an external force, the belief that thoughts are being inserted or withdrawn from your conscious mind, the belief that your thoughts are being broadcast to other people and hearing hallucinated voices which comment on your thoughts or actions, or may have a conversation with other hallucinated voices. It now seems that 'first rank symptoms' are not a reliable method of diagnosing schizophrenia4, however the term might still be used descriptively by mental health professionals.
Diagnostic issues and controversies
It has been argued that the diagnostic approach to schizophrenia is flawed, as it relies on an assumption of a clear dividing line between what is considered to be mental illness (fulfilling the diagnostic criteria) and mental health (not fulfilling the criteria). Recently it has been argued, notably by psychiatrist Jim van Os and psychologist Richard Bentall (in his book Madness Explained), that this makes little sense, as studies have shown that psychotic symptoms are present in many people who never become 'ill' in the sense of feeling distressed, becoming disabled in some way or needing medical assistance.
Of particular concern is that the decision as to whether a symptom is present is a subjective decision by the person making the diagnosis or relies on an incoherent definition (for example, see the entries on delusions and thought disorder for a discussion of this issue). More recently, it has been argued that psychotic symptoms are not a good basis for making a diagnosis of schizophrenia as "psychosis is the 'fever' of mental illness - a serious but nonspecific indicator".5
Proponents have argued for a new approach that would use the presence of specific neurocognitive deficits to make a diagnosis. These often accompany schizophrenia and take the form of a reduction or impairment in basic psychological functions such as memory, attention, and problem solving. It is these sorts of difficulties, rather than the psychotic symptoms (which can in many cases by controlled by antipsychotic medication), which seem to be the cause of most disability in schizophrenia. However, this argument is relatively new and it is unlikely that the method of diagnosing schizophrenia will change radically in the near future.
The diagnostic approach to schizophrenia has also been opposed by the anti-psychiatry movement, who argue that classifying specific thoughts and behaviours as an illness allows social control of people that society finds undesirable but who have committed no crime. They argue that this is a way of unjustly classifying a social problem as a medical one to allow the forcible detention and treatment of people displaying these behaviours, which is something which can be done under mental health legislation in most western countries.
An example of this can be seen in the former Soviet Union, where an additional sub-classification of sluggishly progressing schizophrenia was created. Particularly in the RSFSR (Russian Soviet Federated Socialist Republic) this diagnosis was used for the purpose of silencing political dissidents or forcing them to recant their ideas by the use of forcible confinement and treatment. In 2000 similar concerns about the abuse of psychiatry to unjustly silence and detain members of the Falun Gong movement by the Chinese government led the American Psychiatric Association's Committee on the Abuse of Psychiatry and Psychiatrists to pass a resolution to urge the World Psychiatric Association to investigate the situation in China.
Western psychiatric medicine tends to favour a definition of symptoms that depends on form rather than content (an innovation first argued for by psychiatrists Karl Jaspers and Kurt Schneider). Therefore, you should be able to believe anything, however unusual or socially unacceptable, without being diagnosed delusional, unless your belief is judged to be held in a particular way. In principle this would stop people being forcibly detained or treated simply for what they believe. However, in practice the distinction between form and content is not easy, or sometimes possible, to make (see delusion). This had led to accusations by anti-psychiatry, surrealist and mental health system survivor groups that psychiatric abuses exist to some extent in the West as well.
Treatment
The first line treatment for schizophrenia is usually the use of antipsychotic medication. The newer atypical antipsychotic medication (such as olanzapine, risperidone and clozapine) is preferred over older typical antipsychotic medication (such as chlorpromazine and haloperidol), as the atypicals have different side effect profiles, including less frequent development of extrapyramidal side-effects. However, it is still unclear whether newer drugs reduce the chances of developing the rare but potentially life-threatening neuroleptic malignant syndrome.
Atypical antipsychotics have been claimed to have additional beneficial effects on negative as well as positive symptoms. However, the newer drugs are much more costly as they are still within patent, whereas the older drugs are available in inexpensive generic forms. Aripiprazole a drug from a new class of antipsychotic drugs (variously named 'dopamine system stabilisers' or 'partial dopamine agonists') has recently been developed and early research suggests that it may be a safe and effective treatment for schizophrenia.
Hospitalisation may occur with severe episodes. This can be voluntary or (if mental health legislation allows it) involuntary (called civil or involuntary commitment). Mental health legislation may also allow a person to be treated against their will. However, in many countries such legislation does not exist, or does not have the power to enforce involuntary hospitalisation or treatment.
Psychotherapy or other forms of talk therapy may be offered, with cognitive behavioural therapy being the most frequently used. This may focus on the direct reduction of the symptoms, or on related aspects, such as issues of self-esteem, social functioning, and insight. There have been some promising results with cognitive behavioural therapy, but the balance of current evidence is inconclusive.
Other support services may also be available such as drop-in centres, visits from members of a 'community mental health team' and patient-led support groups.
In many non-Western societies, schizophrenia may be treated with more informal, community-led methods. A particularly sobering thought for Western psychiatry is that outcome for people diagnosed as schizophrenic in non-Western countries may be actually be much better18 than for people in the West. The reasons for this are still far from clear, although cross-cultural studies are being conducted to find out why.
This issue was recently addressed in a highly critical opinion piece (full article here (
http://www.usatoday.com/usatonline/20020304/3909657s.htm) in the American newspaper USA Today, which noted that the rate of recovery is much lower in the United States and other developed nations than in third world countries.
Quote: Most Americans are unaware that the World Health Organization (WHO) has repeatedly found that long-term schizophrenia outcomes are much worse in the USA and other developed countries than in poor ones such as India and Nigeria, where relatively few patients are on anti-psychotic medications. In undeveloped countries, nearly two-thirds of schizophrenia patients are doing fairly well five years after initial diagnosis; about 40% have basically recovered. But in the USA and other developed countries, most patients become chronically ill. The outcome differences are so marked that WHO concluded that living in a developed country is a strong predictor that a patient never will fully recover.
Prognosis
Prognosis for any particular individual affected by schizophrenia is particularly hard to judge as treatment and access to treatment is continually changing as new methods become available and medical recommendations change.
However, retrospective studies have shown that about a third of people make a full recovery, about a third show improvement but not a full recovery, and a third remain ill.
There is an extremely high suicide rate associated with schizophrenia. A recent study showed that 30% of patients diagnosed with this condition had attempted suicide at least once during their lifetime. Another study suggested that 10% of persons with schizophrenia die by suicide.
Schizophrenia and drug use
Schizophrenia can sometimes be triggered by heavy use of hallucinogenic drugs, especially LSD; but it appears that one has to have a predisposition towards developing schizophrenia for this to occur. There is also some evidence suggesting that people suffering schizophrenia but responding to treatment can have an episode as a result of use of LSD. Ironically, it was mainly for experimental treatment of schizophrenia that LSD administration was legal briefly before the popularity of that drug led to its criminalization. Methamphetamine, ketamine and PCP also mimic the symptoms of schizophrenia, and can trigger ongoing symptoms of schizophrenia in those who are vulnerable.
There is now increasing evidence that cannabis use can be a contributing trigger to developing schizophrenia. The most recent studies suggest that cannabis is neither a sufficient nor necessary factor in developing schizophrenia, but that cannabis may significantly increase the risk of developing schizophrenia and may be, among others, a significant causal factor.
It has been noted that the majority of people with schizophrenia (estimated between between 75% and 90%) smoke tobacco. However, people diagnosed with schizophrenia have a much lower than average chance of getting and dying from lung cancer. While the reason for this is unknown, it may be because of a genetic resistance to the cancer, a side-effect of drugs being taken, or a statistical effect of increased likelihood of dying from causes other than lung cancer. It is argued that the increased level of smoking in schizophrenia may be due to a desire to self-medicate with nicotine. A recent study of over 50,000 Swedish conscripts found that there was a small but significant protective effect of smoking cigarettes on the risk of developing schizophrenia later in life. Whilst the authors of the study stressed that the risks of smoking far outweigh these minor benefits, this study provides further evidence for the 'self-medication' theory of smoking in schizophrenia and may gives clues as to how schizophrenia might develop at the molecular level.
Delusional disorder
Delusional disorder is a psychiatric diagnosis denoting a mental illness that involves holding one or more non-bizarre delusions in the absence of any other significant psychopathology (signs or symptoms of mental illness). In particular a person with delusional disorder has never met any other criteria for schizophrenia and does not have any marked hallucinations, although tactile (touch) or olfactory (smell) hallucinations may be present if they are related to the theme of the delusion.
A person with delusional disorder can be quite functional and does not tend to show any odd or bizarre behaviour except as a direct result of the delusional belief.
It is worth noting that the term paranoia was previously used in psychiatry to denote what is now called 'delusional disorder'. The modern psychiatric use of the word paranoia is subtly different but now rarely refers to this specific diagnosis.
Delusional disorder may typically be one of the following types:
· Erotomanic Type (see erotomania): delusion that another person, usually of higher status, is in love with the individual.
· Grandiose Type: delusion of inflated worth, power, knowledge, identity, or special relationship to a deity or famous person (e.g. see Jerusalem syndrome)
· Jealous Type: delusion that the individual's sexual partner is unfaithful (see delusional jealousy).
· Persecutory Type: delusion that the person (or someone to whom the person is close) is being malevolently treated in some way.
· Somatic Type: delusions that the person has some physical defect or general medical condition (for example, see delusional parasitosis).
· A diagnosis of 'mixed type' or 'unspecified type' may also be given if the delusions fall into several or none of these categories.
Hallucination
An hallucination is a false sensory perception in the absence of an external stimulus, as distinct from an illusion which is a misperception of an external stimulus. Hallucinations may occur in any sensory modality - visual, auditory, olfactory, gustatory, tactile or mixed.
The word 'hallucinatory' has its roots in the Latin hallucinari or allucinari, meaning 'to wander in mind'. The first usage of the word 'hallucination' in the English language is recorded as by the English physician Sir Thomas Browne in 1642. However, it was first used in its current sense by psychiatrist Jean-Etienne Esquirol in 1837.
Florid hallucinations are usually associated with drug use (particularly hallucinogenic drugs), sleep deprivation, psychosis or neurological illness.
However, studies have shown that hallucinatory experiences are common across the population as a whole. Previous studies, one as early as 18941, have reported that approximately 10% of the population experience hallucinations. A recent survey of over 13,000 people2 reported a much higher figure with almost 39% of people reported hallucinatory experiences, 27% of which reported daytime hallucinations, mostly outside the context of illness or drug use. From this survery, olfactory (smell) and gustatory (taste) hallucinations seem the most common in the general population.
Auditory hallucinations (particularly of one or more talking voices) are particularly associated with psychotic disorders such as schizophrenia, and hold special significance in diagnosing these conditions. This does not mean that the experience of 'hearing voices' is necessarily a sign of mental illness and many people may have these or similar hallucinations without ever becoming impaired or distressed in any way.
Various theories have been put forward to explain the occurrence of hallucinations. When psychodynamic (Freudian) theories were popular in psychiatry, hallucinations were seen as a projection of unconscious wishes and desires. As biological theories have become orthodox, hallucinations are more often thought of (by psychiatrists at least) as being caused by functional deficits in the brain. With reference to mental illness, the function (or dysfunction) of the neurotransmitter dopamine is thought to be particularly important.
Psychological research has argued that hallucinations may result from biases in what are known as metacognitive abilities. These are abilities that allow us to monitor or draw inferences from our own internal psychological states (such as intentions, memories, beliefs and thoughts). The ability to discriminate between self-generated and external sources of information is considered to be an important metacognitive skill and one which may break down to cause hallucinatory experiences.
Paranoia
Paranoia is excessive concern about one's own well being, sometimes suggesting the person holds persecutory beliefs concerning a threat to themselves or their property.
In the original Greek (paranoia) means self-referential, and it is this meaning which has been adopted in psychiatry, especially European psychiatry, in reference to a delusional belief (see delusions). Specifically, the term paranoia is used to denote a delusional belief that is self-referential (see also ideas of reference). The delusional belief may not necessarily be persecutory. For example, a person who has a delusional belief that they are an important figure (such as being Jesus, Napoleon, or the Dalai Lama) may be diagnosed as having a paranoid belief or, if they hold this belief in the context of schizophrenia, as having paranoid schizophrenia. Paranoia and delusions in general are considered an important (if not the most important) diagnostic feature of psychosis.
The term 'paranoia' was previously used in psychiatry used to describe an isolated delusion. The presence of one of these in the absence of other symptoms of dementia praecox led Emil Kraepelin to create the diagnostic category of 'pure paranoia'. This diagnostic category is covered by what is now classified as delusional disorder. That is, a mental illness that involves one or more non-bizarre delusions with the absence of any other psychopathology (signs or symptoms of mental illness).
Common paranoid delusions may include the belief that the person is being followed, poisoned or loved at a distance (often by a media figure or important person, a delusion known as erotomania or De Clerambault syndrome). Other common paranoid delusions include the belief that the person has an imaginary disease or parasitic infection (delusional parasitosis), that the person is on a special quest or has been chosen by God, that the person has had thoughts inserted or removed from conscious thought or that the person's actions are being controlled by an external force (see mind control).
Paranoia is often associated with psychotic illnesses, particularly schizophrenia, although attenuated features may be present in other primarily non-psychotic diagnoses, such as paranoid personality disorder.
Many despotic rulers (for example Stalin) allegedly suffered from paranoia. This presents an interesting question because in Stalin's case, it is quite likely that many people really were out to get him (some theories state he was finally poisoned). Might it be that with enough enemies, it is impossible to be clinically paranoid? This begs interesting philosophical questions about the criteria by which we can diagnose a belief as paranoid or delusional.
Clinically, paranoid beliefs can be categorised into a number of types, although these are now listed as sub-types of delusional disorder (see that article for more details).
Schizotypal personality disorder
Some people believe that schizotypal personality disorder represents a milder form of the much more serious schizophrenia. This particular personality disorder is most often characterized by a want for social isolation, odd forms of thinking and perception, the belief that they have extra sensory abilities, and over-elaborate speech patterns that are difficult to follow.
