Course of Schizophrenia
Schizophrenia is less common than many other major psychiatric disorders, such as major depressive disorder (depression) or bipolar disorder. Schizophrenia affects about 1% of the population in the United States. Every year, one person in 10,000 will be diagnosed with schizophrenia. Full recovery is rare, and intensity may depend on age of onset, sex, and environment.
There is no sex-related difference for the prevalence of schizophrenia among men and women. The average age of onset, however, differs slightly. For men, it is usually between 15 and 25, while women typically experience its onset between 25 and 35. Onset before age 15 and after age 50 is rare.
Prevalence in other countries is difficult to determine, because cultural perceptions change the way we define schizophrenia and its symptoms. However, an international pilot study on schizophrenia conducted by the World Health Organization established a global risk of 1%, with rare exception. It is estimated that people with schizophrenia occupy 10% of hospital beds in the United States, and that 30% of people with the disease are hospitalized. Roughly 10% of people with schizophrenia commit suicide, though as many as 50% of them may attempt it.
Schizophrenia worsens in 75% of people after its onset. About 25% of people experience an abrupt onset of sudden psychosis. However, most people enter a phase known as the prodromal phase, during which certain signs and symptoms precipitate an acute episode. The following signs are common:
- Eccentric ideas
- Erratic behavior (e.g., angry outbursts)
- Loss of interest or volition
- Persecutory thoughts
- Poor hygiene
- Social withdrawal
- Strange emotional affect
These behaviors worsen gradually and eventually become psychotic symptoms. An acute episode of psychosis typically features one or many positive symptoms and leads to notable dysfunction, which is usually chronic.
A person with schizophrenia rarely returns to normalcy and regains complete function after an acute psychotic episode, especially men. Recurrence of acute episodes is likely.
Changes in mood often occur with schizophrenia. More than 50% of people are depressed during their illness. Some of these people are also diagnosed with schizoaffective disorder, which may feature depressive or manic episodes.
Positive outcome is associated with an acute (quick and brief) and deeply symptomatic onset, particularly if it occurs after teens and features obvious positive symptoms. The following factors more often result in poor prognosis:
- Gradual onset (especially at a young age)
- No obvious precipitating signs
- Predominance of negative symptoms
- Family history
- CT scan abnormalities
Computerized tomography (CT scan) shows abnormal brain structure in many, but not all, people with schizophrenia. Abnormalities of the brain are also associated with early onset, negative symptoms, poor prognosis, and men.