What is the scientific and clinical evidence for the effectiveness of residential group activities and therapies in treating depression?/Systematic Reviews and Meta-Analyses

Summary

The highest-quality evidence comes from three systematic reviews and meta-analyses published between 2001 and 2024. The anchor finding is Cuijpers et al. (2021), a meta-analysis of 32 randomised controlled trials which found that psychological treatments delivered in institutional settings (including psychiatric inpatient units) produce a small-to-moderate but significant and sustained reduction in depressive symptoms (g=0.42, adjusted for publication bias g=0.27). Two large systematic reviews on day hospital and partial hospitalisation (Marshall et al. 2001; Horvitz-Lennon et al. 2001) found outcomes equivalent to full inpatient admission for appropriately selected patients, at substantially lower cost.

The evidence base is limited in volume — far fewer trials exist for institutional settings than for outpatient psychotherapy — but consistent in direction.

Cuijpers et al. (2021): Psychotherapy in Institutional Settings

Reference: Cuijpers P, Ciharova M, Miguel C, Harrer M, Ebert DD, Brakemeier E-L, et al. Psychological treatment of depression in institutional settings: A meta-analytic review. J Affect Disord. 2021;286:340–350. DOI

This is the most directly relevant meta-analysis to the question. Key findings:

32 randomised trials with 37 comparisons between psychotherapy and control conditions
Overall effect size: g=0.42 (95% CI: 0.29–0.56) — a small-to-moderate effect
After adjustment for publication bias: g=0.27 (95% CI: 0.12–0.42) — still significant
In studies with low risk of bias: g=0.32 (95% CI: 0.11–0.52)
Effects were largely retained at 9–15 months follow-up and remained significant after adjustment for publication bias
Heterogeneity was low to moderate (I²=33; 95% CI: 0–55)
Found no significant difference across types of institutional settings, including psychiatric inpatient settings and nursing homes (though nursing home studies lacked low risk of bias)

The meta-analysis included cognitive behavioural therapy, behavioural activation, interpersonal therapy, problem-solving therapy, and other psychotherapeutic modalities. Most were delivered in group or mixed individual-group formats within institutional settings.

Limitations noted by authors: Small number of studies overall; high risk of bias in a considerable number of trials; different types of institutional settings pooled together.

Marshall et al. (2001): Day Hospital vs Inpatient Admission

Reference: Marshall M, Crowther R, Almaraz-Serrano A, Creed F, Sledge W, Kluiter H, et al. Systematic reviews of the effectiveness of day care for people with severe mental disorders. Health Technol Assess. 2001;5(21):1–75. DOI

A UK Health Technology Assessment programme review covering three related questions. The most relevant section examined acute day hospital versus inpatient admission:

9 randomised controlled trials involving 1,568 randomised patients and 2,268 assessed for suitability
Day hospital was feasible for 23–38% of those currently admitted to inpatient care
No difference in total hospital days between day hospital and inpatient groups
Day hospital patients showed more rapid improvement in mental state (significant time-treatment interaction, p=0.002)
No difference in readmission rates (RR=0.91; 95% CI: 0.72–1.15)
Day hospital care was 20.9% to 36.9% cheaper than inpatient care across four of five trials
No significant difference in social functioning outcomes

For day treatment programmes vs outpatient care for non-psychotic disorders (which includes depression): two of five identified trials found day treatment programmes were superior to continuing outpatient care in improving psychiatric symptoms. No evidence of difference on other clinical or social variables or on costs.

Horvitz-Lennon et al. (2001): Partial vs Full Hospitalisation

Reference: Horvitz-Lennon M, Normand SL, Gaccione P, Frank RG. Partial versus full hospitalization for adults in psychiatric distress: a systematic review of the published literature (1957–1997). Am J Psychiatry. 2001;158(5):676–685. DOI

18 investigations published between 1957 and 1997 systematically reviewed
On measures of psychopathology, social functioning, family burden, and service utilisation, found no evidence of differential outcome between partial and full hospitalisation
Patient and family satisfaction favoured partial hospitalisation within 1 year of discharge, with the largest gap at 7–12 months
Over half of eligible patients were excluded a priori, limiting generalisability

The authors concluded that while partial hospitalisation is not suitable for all patients, outcomes for those who were enrolled were no different from inpatients — a finding that has held up in subsequent research.

Other Relevant Reviews

Stuart et al. (1997) — Review on cognitive therapy with inpatients, describing how the therapeutic milieu of inpatient units includes group psychotherapy and one-on-one therapy. Found that inpatient cognitive therapy enhances continuity of care after discharge. PMID: 9034811
Rosie et al. (1995) — Described a successful day treatment programme providing four months of intensive psychodynamic group-oriented milieu treatment for patients with personality disorders and recurrent major depression. PMID: 8829782

Synthesis

The meta-analytic evidence consistently supports a small-to-moderate benefit of psychological therapies in institutional/residential settings for depression. The effect is modest (g≈0.3–0.4 after adjustment) but statistically significant and sustained at follow-up. Day hospital and partial hospitalisation models produce outcomes equivalent to full inpatient admission for a substantial proportion of patients, with better patient satisfaction and lower costs.

However, the total number of high-quality trials is small compared to the outpatient psychotherapy literature, and most studies group together various institutional settings and therapeutic modalities, making it difficult to isolate the effect of specific residential group activities.