WordNet (r) 3.0 (2006):

psychiatrist
    n 1: a physician who specializes in psychiatry [syn:
         psychiatrist, head-shrinker, shrink]

Moby Thesaurus II by Grady Ward, 1.0:

59 Moby Thesaurus words for "psychiatrist":
   Adler, Freud, Horney, Pavlov, Reich, Skinner, Watson, alienist,
   analyst, anesthesiologist, behavior therapist, cardiologist,
   chiropodist, clinical psychologist, dermatologist, eye doctor,
   eye-ear-nose-throat specialist, geriatrician, gerontologist,
   gynecologist, headshrinker, hypnotherapist, immunologist,
   industrial psychologist, internist, narcotherapist, neurologist,
   neuropsychiatrist, obstetrician, oculist, ophthalmologist,
   orthopedist, otolaryngologist, otologist, pathologist,
   pediatrician, pediatrist, podiatrist, psychoanalyst,
   psychoanalyzer, psychobiologist, psychochemist, psychographer,
   psychologist, psychologue, psychopathist, psychopathologist,
   psychophysicist, psychophysiologist, psychotechnologist,
   psychotherapeutist, psychotherapist, radiologist, serologist,
   shrink, shrinker, skin man, somatist, specialist