Schizophrenia

Schizophrenia is a mental disorder characterized variously by hallucinations (typically, hearing voices), delusions, disorganized thinking or behavior, and flat or inappropriate affect. Symptoms develop gradually and typically begin during young adulthood. There is no objective diagnostic test; diagnosis is based on observed behavior, a psychiatric history that includes the person's reported experiences, and reports of others familiar with the person. For a formal diagnosis, the described symptoms need to have been present for at least six months (according to the DSM-5) or one month (according to the ICD-11). Many people with schizophrenia have other mental disorders, especially mood, anxiety, and substance use disorders, as well as obsessive–compulsive disorder (OCD).
The lifetime prevalence of developing schizophrenia is about 0.3% to 0.7%. In 2017, there were an estimated 1.1 million new cases and in 2022 a total of 24 million cases globally. Males are more often affected and on average have an earlier onset than females. The causes of schizophrenia may include genetic and environmental factors. Genetic factors include a variety of common and rare genetic variants. Possible environmental factors include being raised in a city, childhood adversity, cannabis use during adolescence, infections, the age of a person's mother or father, and poor nutrition during pregnancy.
About half of those diagnosed with schizophrenia will experience a marked improvement over the long term with no further relapses, and a small proportion of these will recover completely. The other half will have a lifelong impairment. In severe cases, people may be admitted to hospitals. Social problems such as long-term unemployment, poverty, homelessness, exploitation, and victimization are commonly correlated with schizophrenia. Compared to the general population, people with schizophrenia have a higher suicide rate (about 5% overall) and more physical health problems, leading to an average decrease in life expectancy by 20 to 28 years. In 2015, an estimated 17,000 deaths were linked to schizophrenia.
The mainstay of treatment is antipsychotic medication, including olanzapine and risperidone, along with counseling, job training, and social rehabilitation. Up to a third of people do not respond to initial antipsychotics, in which case clozapine is offered. Most antipsychotics improve schizophrenia symptoms, with clozapine the most effective overall; side effects vary considerably and guide treatment choices. In situations where doctors judge that there is a risk of harm to self or others, they may impose short involuntary hospitalization. Long-term hospitalization is used on a small number of people with severe schizophrenia. In some countries where supportive services are limited or unavailable, long-term hospital stays are more common.