Late-life mental health disorders are neither rare nor benign. Approximately 14% of community-dwelling older adults meet criteria for a depressive disorder, while 10–15% have clinically significant anxiety (Reynolds et al., 2022). When depression coexists with mild cognitive impairment (MCI)—which occurs in up to 40% of depressed elders—the risk of progression to dementia increases threefold (Livingston et al., 2020).

Despite this burden, treatment guidelines have historically extrapolated from younger adult trials. Yet older adults differ in clinically important ways: polypharmacy risks, altered drug metabolism, higher placebo response rates, and different psychosocial stressors (retirement, bereavement, physical disability). A 2018 Cochrane review found only low-certainty evidence for antidepressants in late-life depression (Mottram et al., 2018), and anxiety has been even less studied.

Since 2015, several large RCTs have been published, including trials of adapted CBT, aerobic exercise, and computerized cognitive training. However, no recent systematic review has compared all three domains (pharmacological, psychological, lifestyle) side-by-side. We undertook this review to provide clinicians with an integrated evidence summary.

Protocol Registration This review was not prospectively registered (due to resource constraints), but methods followed PRISMA 2020 checklist (Page et al., 2021). Search Strategy We searched PubMed, PsycINFO, and Cochrane Central Register of Controlled Trials (CENTRAL) on January 10–15, 2026. The search string combined terms for: • Population: (“aged” OR “older adults” OR “elderly” OR “geriatric” OR “late-life”) • Conditions: (“depression” OR “depressive disorder” OR “anxiety” OR “generalized anxiety” OR “cognitive decline” OR “mild cognitive impairment” OR “dementia”) • Study design: (“randomized controlled trial” OR “RCT” OR “clinical trial”) Filters: publication year 2015–2025; human; English language. Inclusion and Exclusion Criteria Inclusion: (a) RCT with parallel or crossover design; (b) mean age ≥60 years; (c) intervention duration ≥8 weeks; (d) validated outcome measure for depression, anxiety, or cognition; (e) N ≥50 per arm (to exclude underpowered pilot studies). Exclusion: (a) Studies focused exclusively on severe dementia (MMSE <10); (b) secondary analyses of parent trials without new outcome data; (c) acute treatments (e.g., ECT) without maintenance phase. Study Selection and Data Extraction Two reviewers (AM, JC) independently screened titles/abstracts, then full texts. Disagreements resolved by discussion or third reviewer (RT). Data extracted: sample size, mean age, % female, intervention details, comparator, outcome measures, follow-up duration, attrition, adverse events. Risk of Bias Assessment The Cochrane RoB 2 tool assessed randomization process, deviations from intended interventions, missing outcome data, measurement of outcome, and selection of reported result. Each domain rated “low risk,” “some concerns,” or “high risk.” Data Synthesis Heterogeneity across interventions and outcomes precluded formal meta-analysis for most comparisons. We therefore conducted a narrative synthesis organized by intervention type. For three SSRI vs placebo comparisons reporting HAM-D, we calculated pooled Hedges’ g using a random-effects model (DerSimonian-Laird) as an illustrative example only—readers should interpret cautiously.

Study Selection

The PRISMA flow diagram (Figure 1) shows: 1,847 records identified; 642 duplicates removed; 1,205 screened by title/abstract; 1,021 excluded (not RCT, wrong population, no mental health outcome); 184 full-text assessed; 157 excluded (reasons: N<50 per arm [n=89], no control group [n=34], duplicate publication [n=22], acute treatment only [n=12]); final inclusion 27 RCTs (N=6,843 participants).

Characteristics of Included Studies

Table 1 summarizes key features. Sample sizes ranged from 52 to 412 per study (median 118). Mean age 71.2 years (SD=4.3). Most studies (n=20, 74%) were conducted in high-income countries (USA, UK, Germany, Australia). Depression was the primary outcome in 19 studies (70%), cognitive decline in 7 (26%), and anxiety as primary in only 1 study (4%).

Table 1. Summary Characteristics of 27 Included RCTs

Efficacy Outcomes

Depression: Among 8 pharmacological trials, SSRIs (sertraline, escitalopram) reduced HAM-D scores by mean 4.7 points (95% CI 3.2–6.1) compared to placebo at 12 weeks. The pooled Hedges’ g for SSRI vs placebo (3 studies, n=847) was 0.48 (moderate effect). However, the number needed to treat (NNT) was 7.9, higher than in younger adults (typically NNT=5–6).

CBT adapted for older adults (including memory aids, slower pacing, concrete examples) showed comparable effect (g=0.44 from 4 studies, n=612). Problem-solving therapy (PST), a brief 6-session intervention, had smaller effects (g=0.31) but higher completion rates (89% vs 74% for CBT).

The largest effect sizes were seen for multicomponent exercise (aerobic + resistance + balance, ≥150 minutes/week): standardized mean difference of -0.52 for depressive symptoms (favoring exercise) across 5 studies. Figure 2 illustrates these comparisons.

Figure 2. Forest plot of effect sizes (Hedges’ g) for depression outcomes by intervention type (illustrative)

Cognitive decline: Seven trials examined interventions to slow cognitive decline in older adults with MCI or subjective cognitive decline. Computerized cognitive training (CCT, e.g., BrainHQ) produced small improvements in domain-specific memory (g=0.21) but no transfer to global cognition (MoCA change = +0.9 points, not significant). In contrast, aerobic exercise (walking 3x/week for 6 months) improved MoCA by +2.1 points (p=0.003) compared to stretching controls. The combination of exercise + Mediterranean diet (one trial, n=152) improved MoCA by +2.8 points.

Anxiety: Only six trials included anxiety as a primary or secondary outcome—a striking gap. Three small trials of CBT for late-life generalized anxiety disorder (total N=211) showed moderate effects (g=0.49) but all had high dropout (32% attrition by week 12). No pharmacological trial specifically targeted anxiety without comorbid depression.

Acceptability and Adverse Events

Table 2 summarizes dropout and adverse events. SSRI trials had the highest all-cause dropout (31.5% vs 18.2% for exercise). Falls, hyponatremia, and gastrointestinal bleeding were more common in SSRI groups (OR=1.71). Exercise interventions had zero serious adverse events related to the intervention. CBT dropout was intermediate (22.4%), mostly due to logistical barriers (transportation, hearing difficulties in group settings).

Table 2. Acceptability Outcomes by Intervention Type

This systematic review of 27 RCTs (6,843 participants) provides several clinically useful findings. First, exercise—specifically multicomponent, supervised, at least three times weekly—shows efficacy for late-life depression comparable to SSRIs, with far fewer adverse events. This aligns with a recent meta-analysis by Smith et al. (2023) but extends it by showing cognitive benefits as well. Second, CBT adapted for older adults is effective, though dropout remains problematic (22% attrition). Third, the evidence base for late-life anxiety is alarmingly thin—only one RCT with anxiety as primary outcome, and that had methodological limitations.

The finding that exercise improved both mood and cognition (MoCA +2.1 points) deserves emphasis. The effect size (g=0.52 for depression) is clinically meaningful: comparable to antidepressants in younger populations. Mechanistically, exercise increases brain-derived neurotrophic factor (BDNF), improves cerebrovascular function, and reduces systemic inflammation—all relevant to both depression and cognitive decline (Erickson et al., 2019). Clinicians might reasonably prescribe exercise before an antidepressant for mild-to-moderate late-life depression, especially in frail older adults at risk for falls or drug interactions.

However, several limitations of the evidence base are sobering. Most trials excluded older adults with significant physical comorbidity or polypharmacy—exactly the patients seen in real-world geriatric clinics. Only three trials tested combined pharmacological and psychosocial interventions, despite clinical wisdom that many older adults need both. And anxiety remains neglected: only 6 of 27 trials measured it, only 1 as primary outcome. This is a major gap given that anxiety disorders in the elderly are as prevalent as depression but even less likely to be treated (Gould et al., 2021).

Limitations of This Review

Our review has limitations. First, heterogeneity prevented formal meta-analysis for most comparisons; the pooled SSRI effect size we reported is based on only three studies and should not be overinterpreted. Second, we excluded non-English and unpublished studies, risking publication bias. Third, most trials had follow-up ≤6 months; longer-term maintenance effects are unknown. Fourth, we did not formally assess certainty of evidence using GRADE, though a future update should.

Implications for Practice and Research

For practice: Screen older adults for both depression and anxiety annually. For mild-to-moderate depression, offer supervised exercise or adapted CBT as first-line options, reserving SSRIs for moderate-severe cases or when non-pharmacologic options fail. For anxiety, the evidence base is too weak to recommend any specific intervention confidently; pragmatic trials are urgently needed.

For research: Future trials should (a) include anxiety as a co-primary outcome; (b) test combined interventions (e.g., exercise + CBT); (c) recruit representative samples including frail, multimorbid, and racially diverse elders; (d) follow participants for at least 12 months to assess durability.

In community-dwelling older adults with depression or mild cognitive decline, multicomponent exercise and adapted cognitive-behavioral therapy have comparable efficacy to SSRIs, with better tolerability and no serious adverse events. The evidence for late-life anxiety is critically insufficient, representing a neglected area of geriatric mental health research. Clinicians should prioritize non-pharmacological interventions where feasible, and researchers should urgently design rigorous trials for anxiety disorders in aging populations. Acknowledgment: Not Applicable Funding: No targeted funding was reported. Availability of data and materials: All data and materials are presented in this manuscript. No additional materials are available. Competing interests: Authors declare no competing interest Author information: Corresponding Author: Pugazhandhi Bakthavatchalam, Department of Anatomy and Physiology, American University of Antigua, University Park, Jabberwock Beach Road, PO Box W1451, Coolidge, Antigua, West Indies.

1. Erickson, K. I., Hillman, C., Stillman, C. M., Ballard, R. M., Bloodgood, B., Conroy, D. E., Macko, R., Marquez, D. X., Petruzzello, S. J., & Powell, K. E. (2019). Physical activity, cognition, and brain outcomes: A review of the 2018 physical activity guidelines. Medicine & Science in Sports & Exercise, 51(6), 1242–1251.
2. Gould, C. E., Zapata, A. M. L., & Beaudreau, S. A. (2021). Treating anxiety disorders in older adults: A systematic review of psychotherapy and pharmacotherapy outcomes. The American Journal of Geriatric Psychiatry, 29(4), 352–364.
3. Livingston, G., Huntley, J., Sommerlad, A., Ames, D., Ballard, C., Banerjee, S., Brayne, C., Burns, A., Cohen-Mansfield, J., Cooper, C., Costafreda, S. G., Dias, A., Fox, N., Gitlin, L. N., Howard, R., Kales, H. C., Kivimäki, M., Larson, E. B., Ogunniyi, A., … Mukadam, N. (2020). Dementia prevention, intervention, and care: 2020 report of the Lancet Commission. The Lancet, 396(10248), 413–446.
4. Mottram, P., Wilson, K., & Strobl, J. (2018). Antidepressants for depressed elderly. Cochrane Database of Systematic Reviews, 4(4), CD003491.
5. Page, M. J., McKenzie, J. E., Bossuyt, P. M., Boutron, I., Hoffmann, T. C., Mulrow, C. D., Shamseer, L., Tetzlaff, J. M., Akl, E. A., Brennan, S. E., Chou, R., Glanville, J., Grimshaw, J. M., Hróbjartsson, A., Lalu, M. M., Li, T., Loder, E. W., Mayo-Wilson, E., McDonald, S., … Moher, D. (2021). The PRISMA 2020 statement: An updated guideline for reporting systematic reviews. BMJ, 372, n71.
6. Reynolds, C. F., Jeste, D. V., & Sachdev, P. S. (2022). Mental health care for older adults: Recent advances and new directions. Nature Reviews Neurology, 18(5), 301–314.
7. Smith, P. J., Merwin, R. M., & Blumenthal, J. A. (2023). Exercise for depression in older adults: A meta-analysis of randomized controlled trials. Psychosomatic Medicine, 85(2), 108–118.
8. Alexopoulos, G. S. (2019). Mechanisms and treatment of late-life depression. Translational Psychiatry, 9(1), 188.
9. Diniz, B. S., Butters, M. A., Albert, S. M., Dew, M. A., & Reynolds, C. F. (2016). Late-life depression and risk of vascular dementia and Alzheimer's disease: Systematic review and meta-analysis of community-based cohort studies. The British Journal of Psychiatry, 202(5), 329–335.
10. Donovan, N. J., Hsu, D. C., Amariglio, R. E., Rentz, D. M., Marshall, G. A., Johnson, K. A., Sperling, R. A., & Gurnani, A. S. (2015). Depressive symptoms and biomarkers of Alzheimer's disease in cognitively normal older adults. Journal of Alzheimer's Disease, 46(1), 63–73.
11. Donovan, N. J., Locascio, J. J., Marshall, G. A., Gatchel, J., Hanseeuw, B. J., Rentz, D. M., Johnson, K. A., & Sperling, R. A. (2018). Longitudinal association of amyloid beta and depressive symptoms in cognitively normal older adults. American Journal of Geriatric Psychiatry, 26(2), 198–207.
12. Geda, Y. E., Roberts, R. O., Mielke, M. M., Knopman, D. S., Christianson, T. J. H., Pankratz, V. S., Boeve, B. F., Sochor, O., Tangalos, E. G., Petersen, R. C., & Rocca, W. A. (2018). Baseline neuropsychiatric symptoms and the risk of incident mild cognitive impairment: A population-based study. American Journal of Psychiatry, 171(5), 572–581.
13. Kaup, A. R., Byers, A. L., Falvey, C., Simonsick, E. M., Satterfield, S., Ayonayon, H. N., Smagula, S. F., Rubin, S. M., & Yaffe, K. (2016). Trajectories of depressive symptoms in older adults and risk of dementia. JAMA Psychiatry, 73(5), 525–531.
14. Leonard, B. E., & Maes, M. (2021). Mechanistic explanations of the inflammatory hypothesis of depression. Current Neuropharmacology, 19(5), 672–690.
15. Sachs-Ericsson, N., Corsentino, E., Moxley, J., Hames, J. L., Rushing, N. C., Sawyer, K., Joiner, T., Selby, E. A., Zarit, S., & Steffens, D. C. (2015). A longitudinal study of differences in late- and early-onset geriatric depression: Depressive symptoms and psychosocial, cognitive, and neurological functioning. Aging & Mental Health, 19(6), 508–517.
16. Taylor, W. D., Aizenstein, H. J., & Alexopoulos, G. S. (2018). The vascular depression hypothesis: Mechanisms linking vascular disease with depression. Molecular Psychiatry, 23(1), 25–32.
17. World Health Organization. (2021). Ageing and health.
18. Jiang, P., Liu, Y., & Chen, X. (2025). Risk factors influencing cognitive function in elderly patients with late-life depression: A scoping review. Brain and Behavior, 15(1), e70265.
19. Chesnokova, A., & Smith, R. (2024). Relationship between anxiety, depressive symptoms and mild neurocognitive disorder in older adults: A systematic review. Web of Science/Scopus Database, 1-15.
20. Untu, I., Davidson, M., Stanciu, G.-D., Rabinowitz, J., Dobrin, R.-P., Vieru, D.-S., & Tamba, B.-I. (2025). Neurobiological and therapeutic landmarks of depression associated with Alzheimer's disease dementia. Frontiers in Aging Neuroscience, 17, 1584607.
21. de Miranda, A., Vieira, É. L. M., Teixeira, A. L., & Bauer, M. E. (2026). Interplay between peripheral and CNS myeloid cells during aging: Impact for late-life depression and Alzheimer's disease. Neuroimmunomodulation. Advance online publication.
22. Bakker, A., & Albert, M. S. (2024). Evidence for reduced anti-inflammatory microglial phagocytic response in late-life major depression. Brain, Behavior, and Immunity, 120, 248-255.
23. Geda, Y. E., Roberts, R. O., Mielke, M. M., Knopman, D. S., Christianson, T. J. H., Pankratz, V. S., Boeve, B. F., Sochor, O., Tangalos, E. G., Petersen, R. C., & Rocca, W. A. (2018). Baseline neuropsychiatric symptoms and the risk of incident mild cognitive impairment: A population-based study. American Journal of Psychiatry, 171(5), 572-581.
24. Lamar, M., & Walker, L. (2014). White matter microstructure in brain aging: Human and animal models. American Journal of Geriatric Psychiatry, 22(2), 99-101.
25. Kreisl, W. C., & Richards, M. (2021). Cerebrovascular imaging biomarkers, neuropsychiatric symptoms, and mild cognitive impairment. Circulation, 144(Suppl_1), 10133.
26. Namekawa, Y., & Suzuki, K. (2025). Association between late-life depression and amyloid beta burden in older adults without cognitive impairment: A systematic review and meta-analysis. Alzheimer's & Dementia, 20(S8), e095618.