Mental disorder

A mental disorder is a clinically significant disturbance in an individual’s cognition, emotional regulation, or behaviour that reflects a dysfunction in the psychological, biological, or developmental processes underlying mental functioning. It is typically associated with distress or impairment in social, occupational, or other important areas of functioning.

Source: Mental disorders – Fact sheet (WHO, 2022)
DSM-5 (APA, 2013) and DSM-5-TR Overview (APA,2022)