Effectiveness of psychosocial and lifestyle interventions in promoting behaviour change and improving cognitive outcomes in older people with memory concerns: a systematic review.

BACKGROUND: Older adults with mild cognitive impairment or subjective cognitive decline have a greater dementia risk, particularly those from minority ethnic and socioeconomically disadvantaged backgrounds. Psychosocial and lifestyle interventions targeting modifiable risk factors offer hope for reducing risk, yet behavioural mechanisms remain unclear. This systematic review examines these mechanisms and associated outcomes. METHOD: We searched PubMed, Embase (Ovid), PsycINFO (Ovid), Web of Science, and Scopus for randomised control trials testing interventions that aimed to improve lifestyle and cognition in older adults with memory concerns. We explored behavioural mechanisms using the COM-B model and synthesised intervention effectiveness, overall and within underserved groups. We prioritised lower risk of bias studies. RESULTS: 26 studies described 23 randomised control trials (14 multidomain, 9 single domain interventions). Certainty of evidence that behaviour change was associated with cognition was low. Moderate-certainty evidence indicated that interventions providing a socially supportive environment and combining nutritional education and counselling for 6+ months improved diet. Physical activity improved primarily in interventions incorporating education, structured training, and enablement strategies (e.g., tailored programmes, providing tools). Interventions simultaneously targeting capability, opportunity and motivation showed greater overall effectiveness. Few studies recorded ethnicity (13%) or sociodemographic status (9%), and none explored their impact. CONCLUSIONS: Non-pharmacological interventions can help this population improve their lifestyles if they feel capable, equipped and motivated, highlighting the value of careful design and implementation. There is scarce evidence on how these interventions work for underserved populations. Future research should explore this to inform tailored interventions and develop equitable dementia prevention strategies.