Schizophrenia is a severe mental disorder characterized by psychosis, including hallucinations, delusions, disorganized thinking, and social withdrawal. It usually emerges in late adolescence or early adulthood and affects about 1 percent of the population worldwide. The condition is chronic, with episodes of acute psychosis and periods of partial remission.

Research shows that schizophrenia is highly heritable, with many genetic variants each contributing a small increase in risk. These genes are often involved in brain development, synaptic function, and immune processes. Environmental factors such as pregnancy complications, childhood adversity, cannabis use, and urban upbringing can interact with genetic vulnerability to increase risk. Neuroimaging studies reveal structural and functional brain changes, including reduced gray matter volume in frontal and temporal regions and altered connectivity in key networks.

Dopamine dysregulation in specific brain pathways is a central finding. Excess dopamine activity in the striatum is linked to psychotic symptoms, while reduced dopamine in the frontal cortex relates to cognitive deficits. Glutamate signaling abnormalities, particularly involving NMDA receptors, also appear important, suggesting that schizophrenia involves broader network dysfunction rather than a single neurotransmitter problem.

Cognitive impairment in attention, memory, and executive function is a core feature and a major driver of disability. Current antipsychotic medications primarily target dopamine and are effective for many positive symptoms but less so for negative symptoms and cognition. Newer research aims at earlier detection, interventions during high risk states, and treatments acting on glutamate, inflammation, and synaptic plasticity. There is also growing emphasis on psychosocial therapies, cognitive remediation, and long term recovery oriented care.