Schizophrenia is one of the most disabling and emotionally devastating illnesses known, affecting behavior, emotion, and cognition. It is caused by a combination of genetic and environmental factors. Symptoms include inappropriate emotions, social withdrawal, disordered thought, delusions, paranoia, and hallucinations. After diagnosis, patients often experience extreme fear and social stigma. Treatment focuses on reducing positive symptoms like hallucinations with antipsychotics, but negative symptoms are more difficult to treat and contribute more to long-term disability. Integrated treatment of both mental health and substance abuse issues is important for long-term management of the disorder.