Schizophrenia from the Greek roots schizein (σχίζειν, "to split") and phrēn, phren- (φρήν, φρεν-, "mind") is a psychiatric diagnosis that describes a mental disorder characterized by abnormalities in the perception or expression of reality. It most commonly manifests as auditory hallucinations, paranoid or bizarre delusions, or disorganized speech and thinking with significant social or occupational dysfunction. Onset of symptoms typically occurs in young adulthood, with approximately 0.4–0.6% of the population affected. Diagnosis is based on the patient's self-reported experiences and observed behavior. No laboratory test for schizophrenia currently exists.
Studies suggest that genetics, early environment, neurobiology, psychological and social processes are important contributory factors; some recreational and prescription drugs appear to cause or worsen symptoms. Current psychiatric research is focused on the role of neurobiology, but no single organic cause has been found. Due to the many possible combinations of symptoms, there is debate about whether the diagnosis represents a single disorder or a number of discrete syndromes. For this reason, Eugen Bleuler termed the disease the schizophrenias (plural) when he coined the name. Despite its etymology, schizophrenia is not the same as dissociative identity disorder, previously known as multiple personality disorder or split personality; in popular culture the two are often confused.
Increased dopamine activity in the mesolimbic pathway of the brain is consistently found in schizophrenic individuals. The mainstay of treatment is antipsychotic medication; this type of drug primarily works by suppressing dopamine activity. Dosages of antipsychotics are generally lower than in the early decades of their use. Psychotherapy, vocational and social rehabilitation are also important. In more serious cases—where there is risk to self and others—involuntary hospitalization may be necessary, although hospital stays are less frequent and for shorter periods than they were in previous years.
The disorder is thought to mainly affect cognition, but it also usually contributes to chronic problems with behavior and emotion. People with schizophrenia are likely to have additional (comorbid) conditions, including major depression and anxiety disorders; the lifetime occurrence of substance abuse is around 40%. Social problems, such as long-term unemployment, poverty and homelessness, are common. Furthermore, the average life expectancy of people with the disorder is 10 to 12 years less than those without, due to increased physical health problems and a higher suicide rate.
Late adolescence and early adulthood are peak years for the onset of schizophrenia. These are critical periods in a young adult's social and vocational development, and they can be severely disrupted. To minimize the effect of schizophrenia, much work has recently been done to identify and treat the prodromal (pre-onset) phase of the illness, which has been detected up to 30 months before the onset of symptoms, but may be present longer. Those who go on to develop schizophrenia may experience the non-specific symptoms of social withdrawal, irritability and dysphoria in the prodromal period, and transient or self-limiting psychotic symptoms in the prodromal phase before psychosis becomes apparent.
The psychiatrist Kurt Schneider (1887–1967) listed the forms of psychotic symptoms that he thought distinguished schizophrenia from other psychotic disorders. These are called first-rank symptoms or Schneider's first-rank symptoms, and they include delusions of being controlled by an external force; the belief that thoughts are being inserted into or withdrawn from one's conscious mind; the belief that one's thoughts are being broadcast to other people; and hearing hallucinatory voices that comment on one's thoughts or actions or that have a conversation with other hallucinated voices. The reliability of first-rank symptoms has been questioned, although they have contributed to the current diagnostic criteria.
Diagnosis is based on the self-reported experiences of the person, and abnormalities in behavior reported by family members, friends or co-workers, followed by a clinical assessment by a psychiatrist, social worker, clinical psychologist or other mental health professional. Psychiatric assessment includes a psychiatric history and some form of mental status examination.
The most widely used standardized criteria for diagnosing schizophrenia come from the American Psychiatric Association's Diagnostic and Statistical Manual of Mental Disorders, the current version being DSM-IV-TR, and the World Health Organization's International Statistical Classification of Diseases and Related Health Problems, currently the ICD-10. The latter criteria are typically used in European countries while the DSM criteria are used in the United States and the rest of the world, as well as prevailing in research studies. The ICD-10 criteria put more emphasis on Schneiderian first rank symptoms although, in practice, agreement between the two systems is high. The WHO has developed the tool SCAN (Schedules for Clinical Assessment in Neuropsychiatry) which can be used for diagnosing a number of psychiatric conditions, including schizophrenia.
According to the DSM-IV, to be diagnosed with schizophrenia, three diagnostic criteria must be met.
Note that schizophrenia cannot be diagnosed if symptoms of mood disorder or pervasive developmental disorder are present, or the symptoms are the direct result of a general medical condition or a substance, such as abuse of a drug or medication.
The ICD-10 defines two additional subtypes.
The definitions used for criteria have been criticized as lacking consistency; this is particularly relevant to the evaluation of delusions and thought disorder. 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".
Perhaps because of these factors, studies examining the diagnosis of schizophrenia have typically shown relatively low or inconsistent levels of diagnostic reliability. Most famously, David Rosenhan's 1972 study, published as On being sane in insane places, demonstrated that the diagnosis of schizophrenia was (at least at the time) often subjective and unreliable. More recent studies have found agreement between any two psychiatrists when diagnosing schizophrenia tends to reach about 65% at best. This, and the results of earlier studies of diagnostic reliability (which typically reported even lower levels of agreement) have led some critics to argue that the diagnosis of schizophrenia should be abandoned.
In 2004 in Japan, the Japanese term for schizophrenia was changed from Seishin-Bunretsu-Byo (mind-split-disease) to Tōgō-shitchō-shō (integration disorder). In 2006, campaigners in the UK, under the banner of Campaign for Abolition of the Schizophrenia Label, argued for a similar rejection of the diagnosis of schizophrenia and a different approach to the treatment and understanding of the symptoms currently associated with it.
Alternatively, other proponents have put forward using the presence of specific neurocognitive deficits to make a diagnosis. These take the form of a reduction or impairment in basic psychological functions such as memory, attention, executive function and problem solving. It is these sorts of difficulties, rather than the psychotic symptoms (which can in many cases be 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 diagnosis of schizophrenia has been used for political rather than therapeutic purposes; in the Soviet Union 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 there were similar concerns regarding detention and 'treatment' of practitioners of the Falun Gong movement by the Chinese government. This 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.
While the reliability of the 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), evidence suggests that genetic and environmental factors can act in combination to result in schizophrenia. Evidence suggests that the diagnosis of schizophrenia has a significant heritable component but that onset is significantly influenced by environmental factors or stressors. The idea of an inherent vulnerability (or diathesis) in some people, which can be unmasked by biological, psychological or environmental stressors, is known as the stress-diathesis model. The idea that biological, psychological and social factors are all important is known as the "biopsychosocial" model.
Particular focus has been placed upon the function of dopamine in the mesolimbic pathway of the brain. This focus largely resulted from the accidental finding that a drug group which blocks dopamine function, known as the phenothiazines, could reduce psychotic symptoms. It is also supported by the fact that amphetamines, which triggers the release of dopamine may exacerbate the psychotic symptoms in schizophrenia. An influential theory, known as the Dopamine hypothesis of schizophrenia, proposed that a malfunction involving dopamine pathways was the cause of (the positive symptoms of) schizophrenia. This theory is now thought to be overly simplistic as a complete explanation, partly because newer antipsychotic medication (called atypical antipsychotic medication) can be equally effective as older medication (called typical antipsychotic medication), but also affects serotonin function and may have slightly less of a dopamine blocking effect.
Interest has also focused on the neurotransmitter glutamate and the reduced function of the NMDA glutamate receptor in schizophrenia. This has largely been suggested by abnormally low levels of glutamate receptors found in postmortem brains of people previously diagnosed with schizophrenia and the discovery that the glutamate blocking drugs such as phencyclidine and ketamine can mimic the symptoms and cognitive problems associated with the condition. The fact that reduced glutamate function is linked to poor performance on tests requiring frontal lobe and hippocampal function and that glutamate can affect dopamine function, all of which have been implicated in schizophrenia, have suggested an important mediating (and possibly causal) role of glutamate pathways in schizophrenia. Further support of this theory has come from preliminary trials suggesting the efficacy of coagonists at the NMDA receptor complex in reducing some of the positive symptoms of schizophrenia.
There have also been findings of differences in the size and structure of certain brain areas in schizophrenia, starting with the discovery of ventricular enlargement in those for whom negative symptoms were most prominent. However, this has not proven particularly reliable on the level of the individual person, with considerable variation between patients. More recent studies have shown various differences in brain structure between people with and without diagnoses of schizophrenia. While brain structure changes have been found in people diagnosed with schizophrenia who have never been treated with antipsychotic drugs there is evidence that the medication itself might cause additional changes in the brain's structure. However, as with earlier studies, many of these differences are only reliably detected when comparing groups of people, and are unlikely to predict any differences in brain structure of an individual person with schizophrenia.
The concept of a cure as such remains controversial, as there is no consensus on the definition, although some criteria for the remission of symptoms have recently been suggested. The effectiveness of schizophrenia treatment is often assessed using standardized methods, one of the most common being the Positive and Negative Syndrome Scale (PANSS). Management of symptoms and improving function is thought to be more achievable than a cure. Treatment was revolutionized in the mid 1950s with the development and introduction of chlorpromazine. A recovery model is increasingly adopted, emphasizing hope, empowerment and social inclusion.
Hospitalization may occur with severe episodes of schizophrenia. This can be voluntary or (if mental health legislation allows it) involuntary (called civil or involuntary commitment). Long-term inpatient stays are now less common due to deinstitutionalization, although can still occur. Following (or in lieu of) a hospital admission, support services available can include drop-in centers, visits from members of a community mental health team or Assertive Community Treatment team, supported employment and patient-led support groups.
In many non-Western societies, schizophrenia may only be treated with more informal, community-led methods. Multiple international surveys by the World Health Organization over several decades have indicated that the outcome for people diagnosed with schizophrenia in non-Western countries is on average better there than for people in the West. Many clinicians and researchers suspect the relative levels of social connectedness and acceptance are the difference, although further cross-cultural studies are seeking to clarify the findings.
Although expensive, the newer atypical antipsychotic drugs are usually preferred for initial treatment over the older typical antipsychotics; they are often better tolerated and associated with lower rates of tardive dyskinesia, although they are more likely to induce weight gain and obesity-related diseases. Prolactin elevations have been reported in women with schizophrenia taking atypical antipsychotics. It remains unclear whether the newer antipsychotics reduce the chances of developing neuroleptic malignant syndrome, a rare but serious and potentially fatal neurological disorder most often caused by an adverse reaction to neuroleptic or antipsychotic drugs.
The two classes of antipsychotics are generally thought equally effective for the treatment of the positive symptoms. Some researchers have suggested that the atypicals offer additional benefit for the negative symptoms and cognitive deficits associated with schizophrenia, although the clinical significance of these effects has yet to be established. Recent reviews have refuted the claim that atypical antipsychotics have fewer extrapyramidal side effects than typical antipsychotics, especially when the latter are used in low doses or when low potency antipsychotics are chosen.
Response of symptoms to medication is variable; Treatment-resistant schizophrenia is a term used for the failure of symptoms to respond satisfactorily to at least two different antipsychotics. Patients in this category may be prescribed clozapine, a medication of superior effectiveness but several potentially lethal side effects including agranulocytosis and myocarditis. Clozapine may have the additional benefit of reducing propensity for substance abuse in schizophrenic patients. For other patients who are unwilling or unable to take medication regularly, long-acting depot preparations of antipsychotics may be given every two weeks to achieve control. The United States of America and Australia are two countries with laws allowing the forced administration of this type of medication on those who refuse but are otherwise stable and living in the community. Some findings have found that in the longer-term some individuals may do better not taking antipsychotics. Despite the promising results of early pilot trials, omega-3 fatty acids failed to improve schizophrenic symptoms, according to the most recent meta-analysis.
Cognitive behavioral therapy (CBT) is used to reduce symptoms and improve related issues such as self-esteem, social functioning, and insight. Although the results of early trials were inconclusive, more recent reviews suggest that CBT can be an effective treatment for the psychotic symptoms of schizophrenia. Another approach is cognitive remediation therapy, a technique aimed at remediating the neurocognitive deficits sometimes present in schizophrenia. Based on techniques of neuropsychological rehabilitation, early evidence has shown it to be cognitively effective, with some improvements related to measurable changes in brain activation as measured by fMRI. A similar approach known as cognitive enhancement therapy, which focuses on social cognition as well as neurocognition, has shown efficacy.
Family therapy or education, which addresses the whole family system of an individual with a diagnosis of schizophrenia, has been consistently found to be beneficial, at least if the duration of intervention is longer-term. Aside from therapy, the impact of schizophrenia on families and the burden on carers has been recognized, with the increasing availability of self-help books on the subject. There is also some evidence for benefits from social skills training, although there have also been significant negative findings. Some studies have explored the possible benefits of music therapy and other creative therapies.
The Soteria model is alternative to inpatient hospital treatment using a minimal medication approach. It is described as a milieu-therapeutic recovery method, characterized by its founder as "the 24 hour a day application of interpersonal phenomenologic interventions by a nonprofessional staff, usually without neuroleptic drug treatment, in the context of a small, homelike, quiet, supportive, protective, and tolerant social environment." Although research evidence is limited, a 2008 systematic review found the programme equally as effective as treatment with medication in people diagnosed with first and second episode schizophrenia.
Service-user led movements have become integral to the recovery process in Europe and the United States; groups such as the Hearing Voices Network and the Paranoia Network have developed a self-help approach that aims to provide support and assistance outside the traditional medical model adopted by mainstream psychiatry. By avoiding framing personal experience in terms of criteria for mental illness or mental health, they aim to destigmatize the experience and encourage individual responsibility and a positive self-image. Partnerships between hospitals and consumer-run groups are becoming more common, with services working toward remediating social withdrawal, building social skills and reducing rehospitalization.
Coordinated by the World Health Organization and published in 2001, The International Study of Schizophrenia (ISoS) was a long-term follow-up study of 1633 individuals diagnosed with schizophrenia around the world. The striking difference in course and outcomes was noted; a half of those available for follow-up had a favourable outcome and 16% had a delayed recovery after an early unremitting course. More usually, the course in the first two years predicted the long-term course. Early social intervention was also related to a better outcome. The findings were held as important in moving patients, carers and clinicians away from the prevalent belief of the chronic nature of the condition. A review of major longitudinal studies in North America also noted this large variation in outcomes, although outcome was on average worse than for other psychotic and psychiatric disorders. A moderate number of patients with schizophrenia were seen to remit and remain well; the review raised the question that some may not require maintenance medication.
A clinical study using strict recovery criteria (concurrent remission of positive and negative symptoms and adequate social and vocational functioning continuously for two years) found a recovery rate of 14% within the first five years. A 5-year community study found that 62% showed overall improvement on a composite measure of clinical and functional outcomes.
World Health Organization studies have noted that individuals diagnosed with schizophrenia have much better long-term outcomes in developing countries (India, Colombia and Nigeria) than in developed countries (USA, UK, Ireland, Denmark, Czech Republic, Slovakia, Japan, and Russia), despite antipsychotic drugs not being widely available.
Several factors have been associated with a better overall prognosis: Being female, rapid (vs. insidious) onset of symptoms, older age of first episode, predominantly positive (rather than negative) symptoms, presence of mood symptoms, and good pre-illness functioning. The strengths and internal resources of the individual concerned, such as determination or psychological resilience, have also been associated with better prognosis. The attitude and level of support from people in the individual's life can have a significant impact; research framed in terms of the negative aspects of this—the level of critical comments, hostility, and intrusive or controlling attitudes, termed high 'Expressed emotion'—has consistently indicated links to relapse. Most research on predictive factors is correlational in nature, however, and a clear cause-and-effect relationship is often difficult to establish.
There is a higher than average suicide rate associated with schizophrenia. This has been cited at 10%, but a more recent analysis of studies and statistics revises the estimate at 4.9%, most often occurring in the period following onset or first hospital admission. Several times more attempt suicide. There are a variety of reasons and risk factors.
The occurrence of psychosis in schizophrenia has sometimes been linked to a higher risk of violent acts. Findings on the specific role of delusions or hallucinations have been inconsistent, but have focused on delusional jealousy, perception of threat and command hallucinations. It has been proposed that a certain type of individual with schizophrenia may be most likely to offend, characterized by a history of educational difficulties, low IQ, conduct disorder, early-onset substance misuse and offending prior to diagnosis.
Individuals with a diagnosis of schizophrenia are often the victims of violent crime—at least 14 times more often than they are perpetrators. Another consistent finding is a link to substance misuse, particularly alcohol, among the minority who commit violent acts. Violence by or against individuals with schizophrenia typically occurs in the context of complex social interactions within a family setting, and is also an issue in clinical services and in the wider community.
The concept of schizophrenia as a result of civilization has been developed further by psychologist Julian Jaynes in his 1976 book The Origin of Consciousness in the Breakdown of the Bicameral Mind; he proposed that until the beginning of historic times, schizophrenia or a similar condition was the normal state of human consciousness. This would take the form of a "bicameral mind" where a normal state of low affect, suitable for routine activities, would be interrupted in moments of crisis by "mysterious voices" giving instructions, which early people characterized as interventions from the gods. Researchers into shamanism have speculated that in some cultures schizophrenia or related conditions may predispose an individual to becoming a shaman; the experience of having access to multiple realities is not uncommon in schizophrenia, and is a core experience in many shamanic traditions. Equally, the shaman may have the skill to bring on and direct some of the altered states of consciousness psychiatrists label as illness. Psychohistorians, on the other hand, accept the psychiatric diagnoses. However, unlike the current medical model of mental disorders they may argue that poor parenting in tribal societies causes the shaman's schizoid personalities. Commentators such as Paul Kurtz and others have endorsed the idea that major religious figures experienced psychosis, heard voices and displayed delusions of grandeur.
Psychiatrist Tim Crow has argued that schizophrenia may be the evolutionary price we pay for a left brain hemisphere specialization for language. Since psychosis is associated with greater levels of right brain hemisphere activation and a reduction in the usual left brain hemisphere dominance, our language abilities may have evolved at the cost of causing schizophrenia when this system breaks down. Other approaches have linked schizophrenia to psychological dissociation or states of awareness and identity understood from phenomenological and other perspectives.
Accounts of a schizophrenia-like syndrome are thought to be rare in the historical record prior to the 1800s, although reports of irrational, unintelligible, or uncontrolled behavior were common. There has been an interpretation that brief notes in the Ancient Egyptian Ebers papyrus may imply schizophrenia, but other reviews have not suggested any connection. A review of ancient Greek and Roman literature indicated that although psychosis was described, there was no account of a condition meeting the criteria for schizophrenia. Bizarre psychotic beliefs and behaviors similar to some of the symptoms of schizophrenia were reported in Arabic medical and psychological literature during the Middle Ages, but no condition resembling schizophrenia was reported in a major Islamic textbook of the 15th Century. Given limited historical evidence, schizophrenia (as prevalent as it is today) may be a modern phenomenon, or alternatively it may have been obscured in historical writings by related concepts such as melancholia or mania.
A detailed case report in 1797 concerning James Tilly Matthews, and accounts by Phillipe Pinel published in 1809, are often regarded as the earliest cases of schizophrenia in the medical and psychiatric literature. Schizophrenia was first described as a distinct syndrome affecting teenagers and young adults by Bénédict Morel in 1853, termed démence précoce (literally 'early dementia'). The term dementia praecox was used in 1891 by Arnold Pick to in a case report of a psychotic disorder. In 1893 Emil Kraepelin introduced a broad new distinction in the classification of mental disorders between dementia praecox and mood disorder (termed manic depression and including both unipolar and bipolar depression). Kraepelin believed that dementia praecox was primarily a disease of the brain, and particularly a form of dementia, distinguished from other forms of dementia, such as Alzheimer's disease, which typically occur later in life. Kraepelin's classification slowly gained acceptance. There were objections to the use of the term "dementia" despite cases of recovery, and some defence of diagnoses it replaced such as adolescent insanity.
The word schizophrenia—which translates roughly as "splitting of the mind" and comes from the Greek roots schizein (σχίζειν, "to split") and phrēn, phren- (φρήν, φρεν-, "mind")—was coined by Eugen Bleuler in 1908 and was intended to describe the separation of function between personality, thinking, memory, and perception. Bleuler described the main symptoms as 4 A's: flattened Affect, Autism, impaired Association of ideas and Ambivalence. Bleuler realized that the illness was not a dementia as some of his patients improved rather than deteriorated and hence proposed the term schizophrenia instead.
The term schizophrenia is commonly misunderstood to mean that affected persons have a "split personality". Although some people diagnosed with schizophrenia may hear voices and may experience the voices as distinct personalities, schizophrenia does not involve a person changing among distinct multiple personalities. The confusion arises in part due to the meaning of Bleuler's term schizophrenia (literally "split" or "shattered mind"). The first known misuse of the term to mean "split personality" was in an article by the poet T. S. Eliot in 1933.
In the first half of the twentieth century schizophrenia was considered to be a hereditary defect, and sufferers were subject to eugenics in many countries. Hundreds of thousands were sterilized, with or without consent—the majority in Nazi Germany, the United States, and Scandinavian countries. Along with other people labeled "mentally unfit", many diagnosed with schizophrenia were murdered in the Nazi "Action T4" program.
The diagnostic description of schizophrenia has changed over time. It became clear after the 1971 US-UK Diagnostic Study that schizophrenia was diagnosed to a far greater extent in America than in Europe. This was partly due to looser diagnostic criteria in the US, which used the DSM-II manual, contrasting with Europe and its ICD-9. This was one of the factors in leading to the revision not only of the diagnosis of schizophrenia, but the revision of the whole DSM manual, resulting in the publication of the DSM-III.
Social stigma has been identified as a major obstacle in the recovery of patients with schizophrenia. In a large, representative sample from a 1999 study, 12.8% of Americans believed that individuals with schizophrenia were "very likely" to do something violent against others, and 48.1% said that they were "somewhat likely" to. Over 74% said that people with schizophrenia were either "not very able" or "not able at all" to make decisions concerning their treatment, and 70.2% said the same of money management decisions. The perception of individuals with psychosis as violent has more than doubled in prevalence since the 1950s, according to one meta-analysis.
The book and film A Beautiful Mind chronicled the life of John Forbes Nash, a Nobel Prize-winning mathematician who was diagnosed with schizophrenia. The Marathi film Devrai (featuring Atul Kulkarni) is a presentation of a patient with schizophrenia. The film, set in the Konkan region of Maharashtra in Western India, shows the behavior, mentality, and struggle of the patient as well as his loved-ones. It also portrays the treatment of this mental illness using medication, dedication and plenty of patience by the close relatives of the patient. Other factual books have been written by relatives on family members; Australian journalist Anne Deveson told the story of her son's battle with schizophrenia in Tell me I'm Here, later made into a movie.
In Bulgakov's The Master and Margarita the poet Ivan Bezdomnyj is institutionalized and diagnosed with schizophrenia after witnessing the devil (Woland) predict Berlioz's death. The book The Eden Express by Mark Vonnegut recounts his struggle with schizophrenia and his recovering journey.