HADS — Hospital Anxiety and Depression Scale: when two profiles are better than one
Why measure anxiety and depression simultaneously
Anxiety and depression are the most common comorbid conditions in clinical practice. By various estimates, 40% to 60% of clients with depression simultaneously experience clinically significant anxiety. If a clinician measures only one, they see half the picture. HADS — the Hospital Anxiety and Depression Scale — solves this with a single 14-item instrument that takes 2-5 minutes.
In everyday practice, clinicians tend to administer either the PHQ-9 (depression) or GAD-7 (anxiety), but not both — two separate forms, 16 questions, two calculations. HADS delivers two independent scores from a single administration. With repeated measurements every 2-4 weeks, this advantage compounds: over 12 sessions, HADS saves approximately 60 minutes compared to the PHQ-9 + GAD-7 pair.
HADS was specifically designed to exclude somatic symptoms. None of the 14 items asks about sleep, appetite, or fatigue. This makes the scale significantly more accurate when working with clients who have somatic conditions — from oncology to cardiology.
How HADS works: two profiles in 14 questions
HADS was created by Zigmond and Snaith in 1983 to screen for anxiety and depression in medical hospital patients. The structure is straightforward: 14 items, each scored 0 to 3. Seven items form the anxiety subscale (HADS-A), seven form the depression subscale (HADS-D). Each subscale yields a score from 0 to 21. The systematic review by Bjelland et al. (2002), covering 747 studies, confirmed the reliability of both subscales: Cronbach's α of 0.83 for anxiety and 0.82 for depression.
The authors' key design decision: all HADS items are cognitive and emotional. There is not a single question about physical symptoms. This fundamentally distinguishes HADS from the BDI-II (which includes items on sleep, appetite, fatigue) and PHQ-9 (items on sleep disturbance and energy). In an oncology or cardiology patient, insomnia and fatigue are more often symptoms of the primary condition, not depression. HADS avoids this trap by design.
Thresholds and clinical interpretation
Each subscale is interpreted independently — that is the point of HADS. A client with HADS-A = 14 and HADS-D = 5 has severe anxiety with normal depression. A client with HADS-A = 3 and HADS-D = 16 — the opposite. The total score (HADS-T) may be the same, but the clinical meaning is radically different. The largest meta-analysis by Wu et al. (2021, N=25,574) confirmed: at the ≥7 cutoff, HADS-D sensitivity for detecting major depression is 0.82, specificity 0.78. For HADS-A at ≥8 — sensitivity 0.82 for detecting GAD (Fomenko et al., 2025, Cochrane, 67 studies).
Dual profile: when anxiety and depression diverge
The mean correlation between HADS subscales is 0.56 (Bjelland, 2002). This means approximately 31% shared variance and 69% unique variance. The subscales measure related but distinct constructs. In practice, this means a single client's anxiety and depression can move in different directions during therapy — and only dual measurement makes this visible.
Most factor analyses confirmed a two-factor solution in good accordance with the HADS subscales for Anxiety and Depression, respectively.— Bjelland et al., 2002, Journal of Psychosomatic Research
Imagine: after 6 CBT sessions, a client's HADS-A drops from 15 to 8, while HADS-D rises from 7 to 12. The total score barely changed (22 → 20), but the clinical picture has flipped — anxiety has moved to the subclinical range while depression has become clinically significant. Without the dual profile, the therapist would see only "minimal improvement" instead of a signal to shift the therapy focus.
HADS over time: what a measurement series reveals
Herrmann (1997), summarizing over 200 studies, confirmed: HADS is sensitive to changes both during the course of diseases and in response to psychotherapeutic and pharmacological intervention. This makes it suitable for repeated measurement — the core of measurement-based care. Optimal frequency: every 2-4 weeks during active therapy, monthly during maintenance.
- Parallel decrease in both subscales → therapy is working comprehensively, stay the course
- Anxiety decreasing, depression stable → reassess focus: anhedonia and hopelessness may need targeted work
- Depression decreasing, anxiety stable → add anxiety management techniques (exposure, relaxation)
- Parallel increase in both subscales → warning signal: treatment is not working or an external stressor has emerged
Clinically significant change on HADS is approximately 5 points per subscale. If HADS-A has dropped by 5+ points while HADS-D hasn't changed — this is not "stagnation" but diverging trajectories. Two graphs instead of one = two clinical decisions instead of one.
When HADS excels and when to choose another tool
HADS excels in three situations: somatic comorbidity (oncology, cardiology, neurology — where somatic scales produce false positives), the need for dual screening in minimal time, and longitudinal monitoring where each measurement must yield two trends. The Russian HADS adaptation (Andryushchenko et al., 2003) is validated and included in the Russian Ministry of Health clinical guidelines, confirming its applicability in Russian practice.
HADS is less suitable when a deep assessment of depression is needed — the BDI-II with its 21 items provides significantly more detail. There is no validated HADS version for adolescents under 16. For suicide risk assessment, HADS contains no direct question — additional instruments are needed (BHS, Columbia Protocol). The licensing aspect is also important: HADS is proprietary (GL Assessment), unlike the free PHQ-9 and GAD-7. Choosing an instrument is always a balance between depth, speed, cost, and the clinical task. The strength of HADS lies not in replacing specialized scales, but in the fact that two independent trends from a single administration provide clinical answers that no single measurement can offer.