Branch of psychology concerned with the diagnosis and treatment of mental disorders .
Clinical psychologists evaluate patients through interviews, observation, and psychological tests , and they apply current research findings and methodologies in making diagnoses and assigning treatments. Most clinical psychologists hold an academic degree (Ph.D. or Psy.D.) rather than a medical degree (M.D.); they may provide psychotherapy but cannot prescribe medications. Most practictioners work in hospitals or clinics or in private practice, often in tandem with psychiatrists and social workers, treating mentally or physically disabled patients, prison inmates, drug and alcohol abusers, and geriatric patients, among others. See also psychiatry ; social work .