Schizophrenia (pronounced /ˌskɪtsɵˈfrɛniə/ or /ˌskɪtsɵˈfriːniə/) is a mental disorder characterized by a disintegration of the process of thinking and of emotional responsiveness.[1] It most commonly manifests as auditory hallucinations, paranoid or bizarre delusions, or disorganized speech and thinking, and it is accompanied by significant social or occupational dysfunction. The onset of symptoms typically occurs in young adulthood,[2] with a global lifetime prevalence of around 1.5%.[3][4] Diagnosis is based on the patient's self-reported experiences and observed behavior.
Schizophrenia has increasingly been recognized as a collection of neurodevelopmental disorders that involve alterations in brain circuits.[5] Genetics, early environment, neurobiology, psychological and social processes appear to be 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 this inquiry has not isolated a single organic cause. As a result of the many possible combinations of symptoms, there is debate about whether the diagnosis represents a single disorder or a number of discrete syndromes. Despite the etymology of the term from the Greek roots skhizein (σχίζειν, "to split") and phrēn, phren- (φρήν, φρεν-; "mind"), schizophrenia does not imply a "split mind" and it is not the same as dissociative identity disorder—also known as "multiple personality disorder" or "split personality"—a condition with which it is often confused in public perception.[6]
Unusually high dopamine activity in the mesolimbic pathway of the brain has been found in people with schizophrenia. The mainstay of treatment isantipsychotic 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, and 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 shorter and less frequent than they were in previous times.[7]
The disorder is thought mainly to 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;[8] 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 (about 5%).[9][10]
Schizophrenia has increasingly gained attention among the general public and the scientific community. Indeed, the November 11, 2010 issue of Naturewas devoted to the theme of schizophrenia.[11]