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Schizophrenia - Health Web |
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 Schizophrenia or schizophreneia, meaning "split mind", is a psychiatric diagnosis that describes a mental illness characterized by impairments in the perception or expression of reality, most commonly manifesting as auditory hallucinations, paranoid or bizarre delusions or disorganized speech and thinking in the context of 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 exists.
Studies suggest that genetics, early environment, neurobiology and psychological and social processes are important contributory factors. Current psychiatric research is focused on the role of neurobiology, but a clear organic cause has not 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 synonymous with dissociative identity disorder, previously known as multiple personality disorder or split personality; in popular culture the two are often confused.
Increased dopaminergic activity in the mesolimbic pathway of the brain is a consistent finding. The mainstay of treatment is pharmacotherapy with antipsychotic medications; these primarily work 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, though hospital stays are less frequent and for shorter periods than they were in previous years.
The disorder is primarily thought to affect cognition, but it also usually contributes to chronic problems with behavior and emotion. People diagnosed with schizophrenia are likely to be diagnosed with comorbid conditions, including clinical depression and anxiety disorders; the lifetime prevalence of substance abuse is typically around 40%. Social problems, such as long-term unemployment, poverty and homelessness, are common and life expectancy is decreased; the average life expectancy of people with the disorder is 10 to 12 years less than those without, owing to increased physical health problems and a high suicide rate.
Signs and Symptoms
A person experiencing schizophrenia may demonstrate symptoms such as disorganized thinking, auditory hallucinations, and delusions. In severe cases, the person may be largely mute, remain motionless in bizarre postures, or exhibit purposeless agitation; these are signs of catatonia. The current classification of psychoses holds that symptoms need to have been present for at least one month in a period of at least six months of disturbed functioning. A schizophrenia-like psychosis of shorter duration is termed a schizophreniform disorder. No one sign is diagnostic of schizophrenia, and all can occur in other medical and psychiatric conditions.
Social isolation commonly occurs and may be due to a number of factors. Impairment in social cognition is associated with schizophrenia, as are the active symptoms of paranoia from delusions and hallucinations, and the negative symptoms of apathy and avolition. Many people diagnosed with schizophrenia avoid potentially stressful social situations that may exacerbate mental distress.
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 by disease onset. To minimize the impact 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.
Schneiderian Classification
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.
Positive and Negative Symptoms
Schizophrenia is often described in terms of positive (or productive) and negative (or deficit) symptoms. Positive symptoms include delusions, auditory hallucinations, and thought disorder, and are typically regarded as manifestations of psychosis. Negative symptoms are so-named because they are considered to be the loss or absence of normal traits or abilities, and include features such as flat or blunted affect and emotion, poverty of speech (alogia), anhedonia, and lack of motivation (avolition). Despite the appearance of blunted affect, recent studies indicate that there is often a normal or even heightened level of emotionality in Schizophrenia especially in response to stressful or negative events. A third symptom grouping, the disorganization syndrome, is commonly described, and includes chaotic speech, thought, and behaviour. There is evidence for a number of other symptom classifications.
Diagnosis
Diagnosis is based on the self-reported experiences of the person as well as abnormalities in behavior reported by family members, friends or co-workers, followed by secondary signs observed by a psychiatrist, social worker, clinical psychologist or other clinician in a clinical assessment. There is a list of criteria that must be met for someone to be so diagnosed. These depend on both the presence and duration of certain signs and symptoms.
An initial assessment includes a comprehensive history and physical examination by a physician. Although there are no biological tests which confirm schizophrenia, tests are carried out to exclude medical illnesses which may rarely present with psychotic schizophrenia-like symptoms. These include blood tests measuring TSH to exclude hypo- or hyperthyroidism, basic electrolytes and serum calcium to rule out a metabolic disturbance, full blood count including ESR to rule out a systemic infection or chronic disease, and serology to exclude syphilis or HIV infection; two commonly ordered investigations are EEG to exclude epilepsy, and a CT scan of the head to exclude brain lesions. It is important to rule out a delirium which can be distinguished by visual hallucinations, acute onset and fluctuating level of consciousness and indicates an underlying medical illness. There are several psychiatric illnesses which may present with psychotic symptoms other than schizophrenia . These include bipolar disorder, borderline personality disorder, drug intoxication, brief drug-induced psychosis, and schizophreniform disorder.
Investigations are not generally repeated for relapse unless there is a specific medical indication. These may include serum BSL if olanzapine has previously been prescribed, liver function tests if chlorpromazine or CPK to exclude neuroleptic malignant syndrome. Assessment and treatment are usually done on an outpatient basis; admission to an inpatient facility is considered if there is a risk to self or others.
The most widely used criteria for diagnosing schizophrenia are 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 USA or 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.
Treatment and Services
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). Aiming for management of symptoms and improving function is often 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. The outcome for people diagnosed with schizophrenia in non-Western countries may actually be better than for people in the West. The reasons for this effect are not clear, although cross-cultural studies are being conducted.
Medication
The mainstay of psychiatric treatment for schizophrenia is an antipsychotic medication. These can reduce the "positive" symptoms of psychosis. Most antipsychotics take around 7–14 days to have their main effect.
Though expensive, the newer atypical antipsychotic drugs are usually preferred for initial treatment over the older typical antipsychotics; they are thought to be generally better tolerated and associated with lower rates of tardive dyskinesia, although they are more likely to induce weight gain and obesity-related diseases. 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.
A substantial number of individuals with schizophrenia do not benefit satisfactorily from antipsychotics. "Treatment-resistant schizophrenia" is a term used in psychiatric services 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 potentially superior effectiveness but several potentially lethal side effects including agranulocytosis and myocarditis. 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. 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. Nevertheless, some findings indicate that in the longer-term many individuals do better without taking antipsychotics.
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