A neurodevelopmental disorder characterized by positive symptoms (hallucinations, delusions and disorganized thought and speech) and by negative symptoms (deficiencies in experiencing
pleasure or motivation).
The disorder usually develops in late adolescence or early adulthood, the
time when the brain fully matures.
Treatment includes antipsychotics, which usually have a large effect on symptoms, however compliance is usually poor due to their severe side effects. Cognitive function usually does not improve with treatment, and is a
major source of disability.
Heritability is estimated to be about 80%. Genetic studies implicate general neurodevelopmental pathways, and especially
sperm function, the immune
system, DNA repair and synaptic development. Environmental factors include problems during pregnancy, advanced parental age, childhood adversity, an urban environment, cannabis use in childhood or adolescence and addiction to
alcohol or stimulants.
Complications include suicide (about
5%), uncemployment (about 85%) and social isolation.
About 0.
5% of people suffer from schizophrenia.
