HAM-D

The Hamilton Depression Rating Scale (HAM-D or HDRS) is a clinician-administered assessment developed by Max Hamilton in 1960, making it one of the earliest and most widely used instruments for measuring depression severity. The most common version (HAM-D-17) contains 17 items covering depressed mood, guilt, suicidality, insomnia, work and activities, psychomotor retardation or agitation, anxiety, somatic symptoms, loss of insight, and weight loss. Items are scored on either 3-point (0–2) or 5-point (0–4) scales. The HAM-D has been used extensively in psychedelic depression research, including Imperial College London’s psilocybin trials for treatment-resistant depression. While criticized for heavy weighting of somatic and sleep symptoms (which can inflate scores in medically ill populations), it remains a regulatory standard and enables comparison across decades of antidepressant research.