Psychiatrists are trained first as physicians, and—as such—they may prescribe prescription medication; and specialist psychiatric training begins after medical school in psychiatric residencies: however, their specialty is in mental disorders or forms of mental illness. Clinical psychologists have specialist doctoral degrees in psychology with some clinical and research components. Other clinical practitioners, social workers, mental health counselors, pastoral counselors, and nurses with a specialization in mental health, also often conduct psychotherapy. Many of the wide variety of psychotherapy training programs and institutional settings are multi-professional. In most countries, psychotherapy training are all at a post-graduate level, often at a master's degree (or doctoral) level, over 4 years, with significant supervised practice and clinical placements. Such professionals doing specialized psychotherapeutic work also require a program of continuing professional education after basic professional training.