This document provides an overview of psychiatry and psychiatric disorders. It discusses that psychiatry deals with the diagnosis and treatment of mental disorders manifested by disorders of perception, thinking, emotions, decision making and motor behavior. It notes that psychiatric disorders are widely prevalent and can impact physical health, functioning, and be an economic burden. Common disorders include depression, alcohol use disorder, schizophrenia, and bipolar disorder. The etiology of psychiatric disorders involves complex interactions between biological, psychological and social factors that can predispose, precipitate, or perpetuate conditions. Advances in neuroscience have provided insights into the brain changes associated with psychiatric conditions.