An article in health promotion international sought to determine the effects of various interventions to promote mental health and decrease depressive symptoms in older adults. There were a total of 44 trials were utilized for a meta-analysis to determine effectiveness. The article concludes social activities were statistically significant at improving mental health compared to physical activity, skill training, and reminiscence. The article's most important conclusion states that a longer duration of intervention may increase the effectiveness to reduce depressive symptoms and increase quality of life. The results demonstrated statistically significant improvement for all intervention lasting longer than 3 months.
https://academic.oup.com/heapro/article/26/suppl_1/i85/687327/Psychosocial-interventions-for-the-promotion-of