Long-term observation of a multicomponent cognitive intervention in amnestic mild cognitive impairment (aMCI)

Recent studies demonstrated benefits through cognitive intervention (CI) in subjects with amnestic mild cognitive impairment (aMCI). However, few studies determined long-term effects, conversion rate of MCI-subjects into AD, and the role of early intervention. We evaluated a long-term observation of an early and 8-month time-lagged multicomponent CI on subjects with aMCI with follow-up assessments up to 24 months. Primary outcome were changes in global cognitive functions (Alzheimer's Disease Assessment Scale, ADAS-cog, and Mini Mental Status Examination, MMSE), secondary outcome were change in specific cognitive and non-cognitive functions and conversion into AD. 24 aMCI-subjects were randomly assigned to a 6-months CI (n = 12) and an active control condition (n = 12). Following the control condition participants attended to the CI with 8-month time-lag (IG 2) compared to early intervention (IG 1). 18 participants completed the study after 24 months. Data of 1- and 2-year follow-up revealed a stable intervention-effect on the primary outcome ADAS-cog in the IG 1 (p = .024). Compared to early beginners, IG 2 seemed to benefit from CI to a lesser extent. Only participants of the IG 2 (6 of 12) converted into AD. Cognitive benefits of the CI on global cognitive status appear to be preserved over extended follow-up periods. Early CI may be able to delay conversion to AD. Findings in a small sample of subjects encourage the use of the CI in larger scales studies to confirm effects.