Diagnostic Criteria: These are specific signs, symptoms, behaviors or characteristics that must be present in order to diagnose a particular disorder according to the DSM.
Mental Disorder: A syndrome characterized by clinically significant disturbance in an individual's cognition, emotion regulation, or behavior that reflects a dysfunction in the psychological, biological, or developmental processes underlying mental functioning.
Psychopathology: The scientific study of mental disorders including efforts to understand their genetic, biological, psychological and social causes; effective classification schemes (nosology); course across all stages of development; manifestations; and treatment.