Psychosis is a loss of contact with reality, usually including false beliefs about what is taking place or who one is (delusions) and seeing or hearing things that aren't there (hallucinations).

A number of substances and medical conditions can cause psychosis, including:

• Alcohol and certain illegal drugs, both during use and during withdrawal
• Brain tumors or cysts
• Dementia (including Alzheimer's disease)
• Degenerative brain diseases, such as Parkinson's disease, Huntington's disease, and certain chromosomal disorders
• HIV and other infections that affect the brain
• Some prescription drugs, such as steroids and stimulants
• Some types of epilepsy
• Stroke

Psychosis is also part of a number of psychiatric disorders, including:

• Bipolar disorder (manic or depressed)
• Delusional disorder
• Depression with psychotic features
• Personality disorders (schizotypal, shizoid, paranoid, and sometimes borderline)
• Schizoaffective disorder
• Schizophrenia

Review Date: 02/07/2010
Reviewed By: David B. Merrill, MD, Assistant Clinical Professor of Psychiatry, Department of Psychiatry, Columbia University Medical Center, New York, NY. Also reviewed by David Zieve, MD, MHA, Medical Director, A.D.A.M., Inc.

A.D.A.M., Inc. is accredited by URAC, also known as the American Accreditation HealthCare Commission (www.urac.org)