Scientists have learned a great deal about schizophrenia in the past few decades, but public perception of the disorder is still often rooted in outdated myths.
Schizophrenia is a mental disorder characterized by abnormal social behavior and failure to understand reality. Common symptoms include false beliefs, unclear or confused thinking, hearing voices that others do not, reduced social engagement and emotional expression, and a lack of motivation. People with schizophrenia often have additional mental health problems such as anxiety, depressive, or substance-use disorders. Symptoms typically come on gradually, begin in young adulthood, and last a long time.
The causes of schizophrenia include environmental and genetic factors. Possible environmental factors include being raised in a city, cannabis use during adolescence, certain infections, parental age and poor nutrition during pregnancy. Genetic factors include a variety of common and rare genetic variants. Diagnosis is based on observed behavior, the person's reported experiences and reports of others familiar with the person. During diagnosis a person's culture must also be taken into account. As of 2013 there is no objective test. Schizophrenia does not imply a "split personality" or "dissociative identity disorder" – conditions with which it is often confused in public perception.
The mainstay of treatment is antipsychotic medication, along with counselling, job training and social rehabilitation. It is unclear whether typical or atypical antipsychotics are better. In those who do not improve with other antipsychotics clozapine may be tried. In more serious situations where there is risk to self or others involuntary hospitalization may be necessary, although hospital stays are now shorter and less frequent than they once were.
About 0.3–0.7% of people are affected by schizophrenia during their lifetimes. In 2013 there were an estimated 23.6 million cases globally. Males are more often affected, and on average experience more severe symptoms. About 20% of people do well and a few recover completely. About 50% have lifelong impairment. Social problems, such as long-term unemployment, poverty and homelessness are common. The average life expectancy of people with the disorder is ten to twenty-five years less than for the general population. This is the result of increased physical health problems and a higher suicide rate (about 5%). In 2015 an estimated 17,000 people worldwide died from behavior related to, or caused by, schizophrenia.
Signs and symptoms
Individuals with schizophrenia may experience hallucinations (most reported are hearing voices), delusions (often bizarre or persecutory in nature), and disorganized thinking and speech. The last may range from loss of train of thought, to sentences only loosely connected in meaning, to speech that is not understandable known as word salad. Social withdrawal, sloppiness of dress and hygiene, and loss of motivation and judgment are all common in schizophrenia.
Distortions of self-experience such as feeling as if one's thoughts or feelings are not really one's own to believing thoughts are being inserted into one's mind, sometimes termed passivity phenomena, are also common. There is often an observable pattern of emotional difficulty, for example lack of responsiveness. Impairment in social cognition is associated with schizophrenia, as are symptoms of paranoia. Social isolation commonly occurs. Difficulties in working and long-term memory, attention, executive functioning, and speed of processing also commonly occur. In one uncommon subtype, the person may be largely mute, remain motionless in bizarre postures, or exhibit purposeless agitation, all signs of catatonia. People with schizophrenia often find facial emotion perception to be difficult. It is unclear if the phenomenon called "thought blocking", where a talking person suddenly becomes silent for a few seconds to minutes, occurs in schizophrenia.
About 30 to 50 percent of people with schizophrenia fail to accept that they have an illness or comply with their recommended treatment. Treatment may have some effect on insight.
People with schizophrenia may have a high rate of irritable bowel syndrome but they often do not mention it unless specifically asked. Psychogenic polydipsia, or excessive fluid intake in the absence of physiological reasons to drink, is relatively common in people with schizophrenia.
Genetic
Estimates of the heritability of schizophrenia is around 80%, which implies that 80% of the individual differences in risk to schizophrenia is explained by individual differences in genetics. These estimates vary because of the difficulty in separating genetic and environmental influences. The greatest single risk factor for developing schizophrenia is having a first-degree relative with the disease (risk is 6.5%); more than 40% of monozygotic twins of those with schizophrenia are also affected. If one parent is affected the risk is about 13% and if both are affected the risk is nearly 50%.
Many genes are known to be involved in schizophrenia, each of small effect and unknown transmission and expression. The summation of these effect sizes into a polygenic risk score can explain at least 7% of the variability in liability for schizophrenia. Around 5% of cases of schizophrenia are understood to be at least partially attributable to rare copy number variants (CNVs), including 22q11, 1q21 and 16p11. These rare CNVs increase the risk of an individual developing the disorder by as much as 20-fold, and are frequently comorbid with autism and intellectual disabilities. There is a genetic relation between the common variants which cause schizophrenia and bipolar disorder, an inverse genetic correlation with intelligence and no genetic correlation with immune disorders.
Diagnosis
Criteria
In 2013, the American Psychiatric Association released the fifth edition of the DSM (DSM-5). To be diagnosed with schizophrenia, two diagnostic criteria have to be met over much of the time of a period of at least one month, with a significant impact on social or occupational functioning for at least six months. The person had to be suffering from delusions, hallucinations, or disorganized speech. A second symptom could be negative symptoms, or severely disorganized or catatonic behaviour The definition of schizophrenia remained essentially the same as that specified by the 2000 version of DSM (DSM-IV-TR), but DSM-5 makes a number of changes.
· Subtype classifications – such as catatonic and paranoid schizophrenia – are removed. These were retained in previous revisions largely for reasons of tradition, but had subsequently proved to be of little worth.
· Catatonia is no longer so strongly associated with schizophrenia.
· In describing a person's schizophrenia, it is recommended that a better distinction be made between the current state of the condition and its historical progress, to achieve a clearer overall characterization.
· Special treatment of Schneider's first-rank symptoms is no longer recommended.
· Schizoaffective disorder is better defined to demarcate it more cleanly from schizophrenia.
· An assessment covering eight domains of psychopathology – such as whether hallucination or mania is experienced – is recommended to help clinical decision-making.
The ICD-10 criteria are typically used in European countries, while the DSM criteria are used in the United States and to varying degrees around the world, and are prevailing in research studies. The ICD-10 criteria put more emphasis on Schneiderian first-rank symptoms. In practice, agreement between the two systems is high. The current proposal for the ICD-11 criteria for schizophrenia recommends adding self-disorder as a symptom.
If signs of disturbance are present for more than a month but less than six months, the diagnosis of schizophreniform disorder is applied. Psychotic symptoms lasting less than a month may be diagnosed as brief psychotic disorder, and various conditions may be classed as psychotic disorder not otherwise specified, while schizoaffective disorder is diagnosed if symptoms of mood disorder are substantially present alongside psychotic symptoms. If the psychotic symptoms are the direct physiological result of a general medical condition or a substance, then the diagnosis is one of a psychosis secondary to that condition. Schizophrenia is not diagnosed if symptoms of pervasive developmental disorder are present unless prominent delusions or hallucinations are also present.
Prognosis
Schizophrenia has great human and economic costs. It results in a decreased life expectancy by 10–25 years. This is primarily because of its association with obesity, poor diet, sedentary lifestyles, and smoking, with an increased rate of suicide playing a lesser role. Antipsychotic medications may also increase the risk. These differences in life expectancy increased between the 1970s and 1990s.
Schizophrenia is a major cause of disability, with active psychosis ranked as the third-most-disabling condition after quadriplegia and dementia and ahead of paraplegia and blindness. Approximately three-fourths of people with schizophrenia have ongoing disability with relapses and 16.7 million people globally are deemed to have moderate or severe disability from the condition. Some people do recover completely and others function well in society. Most people with schizophrenia live independently with community support. About 85% are unemployed. Some evidence suggests that paranoid schizophrenia may have a better prospect than other types of schizophrenia for independent living and occupational functioning. In people with a first episode of psychosis a good long-term outcome occurs in 42%, an intermediate outcome in 35% and a poor outcome in 27%. Outcomes for schizophrenia appear better in the developing than the developed world. These conclusions, however, have been questioned.
There is a higher than average suicide rate associated with schizophrenia. This has been cited at 10%, but a more recent analysis revises the estimate to 4.9%, most often occurring in the period following onset or first hospital admission. Several times more (20 to 40%) attempt suicide at least once There are a variety of risk factors, including male gender, depression, and a high intelligence quotient.
Schizophrenia and smoking have shown a strong association in studies worldwide. Use of cigarettes is especially high in individuals diagnosed with schizophrenia, with estimates ranging from 80 to 90% being regular smokers, as compared to 20% of the general population. Those who smoke tend to smoke heavily, and additionally smoke cigarettes with high nicotine content. Among people with schizophrenia use of cannabis is also common.
Thanks to Wikipedia: Schizophrenia