Schizophrenia is a severe psychiatric condition that affects a person's mental and physical well-being by disrupting how their brain works, impacting thoughts, memory, senses and behaviours. It is characterised by a disconnection from reality that can include hallucinations and delusions. Schizophrenia is now viewed as a spectrum of conditions. Key aspects of schizophrenia include:

• Symptoms: Symptoms are categorised as positive, negative and cognitive. Positive symptoms include hallucinations and delusions. Negative symptoms are deficits of normal emotional responses, or of other thought processes, such as a flat affect, poverty of speech, inability to feel pleasure, lack of desire to form relationships and a lack of motivation. Cognitive symptoms affect memory, attention, and the ability to organise thoughts.
• Causes: The exact causes of schizophrenia are not fully known, but it is believed that a mix of genetics, brain chemistry and environmental factors play a part. Changes in certain brain chemicals, like dopamine and glutamate, may contribute to the condition. Neuroimaging studies show changes in the brain structure and central nervous systems of people with schizophrenia, which indicate that it is a brain disease.
• Risk factors: Several factors can increase the risk of developing schizophrenia, including genetic factors, such as a family history of the condition . Environmental risk factors include substance use, maternal obesity , and childhood adversity .
• Diagnosis: Diagnosis typically involves assessing symptoms over a period of time and ruling out other conditions. The criteria for diagnosis can vary, with the ICD criteria typically used in European countries and the DSM criteria used predominantly in the United States and Canada.
• Treatment: The primary treatment for schizophrenia is antipsychotic medication, often combined with psychosocial interventions and social support. Community support services, such as drop-in centers, mental health teams, and support groups are also common. Early diagnosis and treatment are important for better management of the condition. The time between the onset of psychotic symptoms and treatment is associated with a poorer outcome.
• Management: Management of schizophrenia involves a combination of medication, psychosocial interventions and community support. Assertive community treatment (ACT) and intensive care management (ICM) are approaches that provide support in the community, outside of the hospital setting, including assistance with routine matters.
• Stigma: There is considerable stigma associated with schizophrenia. Efforts have been made in some countries to reduce this stigma by changing the name of the condition.

It is important to note that proper treatment of schizophrenia can reduce the risk of suicide.