HADS

The Hospital Anxiety and Depression Scale (HADS) is a 14-item self-report questionnaire developed by Zigmond and Snaith in 1983 to detect anxiety and depression in medical outpatient settings. It comprises two 7-item subscales — HADS-A (anxiety) and HADS-D (depression) — each scored 0–21, with a combined total of 0–42. The scale deliberately excludes somatic symptoms (fatigue, insomnia, pain) that could be confounded by physical illness, making it particularly suitable for medically ill populations. In psychedelic research, the HADS has been prominently used in psilocybin trials for cancer-related psychological distress at NYU (Stephen Ross) and Johns Hopkins (Roland Griffiths), where it served as a primary or co-primary endpoint. Subscale scores of 8–10 indicate borderline cases and 11+ indicates clinical caseness. The HADS has strong reliability (α = 0.80–0.93) and is validated in over 25 languages.