Psychiatry is the branch of medicine focused on the diagnosis, treatment and prevention of mental, emotional and behavioral disorders. A psychiatrist is a medical doctor (an M.D. or D.O.) who specializes in mental health, including substance use disorders. Psychiatrists are qualified to assess both the mental and physical aspects of psychological problems. People seek psychiatric help for many reasons. The problems can be sudden, such as a panic attack, frightening hallucinations, thoughts of suicide, or hearing "voices." Or they may be more long-term, such as feelings of sadness, hopelessness, or anxiousness that never seem to lift or problems functioning, causing everyday life to feel distorted or out of control.