Individualized Cognitive Stimulation in Mild Alzheimer’s Disease: Evidence from a Multicenter RCT

A recent randomized controlled trial conducted across multiple sites in Portugal provides new insight into the clinical utility of individualized cognitive stimulation (iCS) in older adults with mild Alzheimer’s disease (AD).

While global cognitive outcomes remained largely stable, the intervention produced measurable improvements in semantic memory and executive function—two domains closely linked to daily autonomy.

Study Design: Structured and Personalized Interventions

The trial enrolled 62 community-dwelling older adults (mean age 82.7) diagnosed with mild AD. Participants were randomized to receive either iCS or treatment as usual (TAU).

The iCS protocol involved two 45-minute one-on-one sessions per week over 12 weeks, delivered by trained professionals across 13 institutions. Sessions were structured to progressively engage multiple cognitive domains using culturally adapted tools with content targeting language, calculation, semantic processing, and autobiographical recall.

Outcome measures included the Mini-Mental State Examination (MMSE), Alzheimer’s Disease Assessment Scale-Cognitive Subscale (ADAS-Cog), Memory Alteration Test (MAT), Free and Cued Selective Reminding Test (FCSRT), and Frontal Assessment Battery (FAB). Blinded raters assessed participants at baseline, post-intervention, and at 12-week follow-up.

Key Findings: Selective Improvement in Memory and Executive Function

While MMSE and ADAS-Cog scores remained statistically unchanged between groups, subdomain analysis within the ADAS-Cog indicated a trend toward improved word recall among iCS participants. This trend approached the threshold commonly cited as clinically relevant in dementia trials (≥3-point change).

Notably, the iCS group demonstrated significant gains on the MAT, particularly in encoding and semantic memory, with these improvements persisting at the 12-week follow-up. Free delayed recall, as measured by the FCSRT, also improved significantly, reinforcing the intervention’s effect on retrieval processes.

Executive function, evaluated via the FAB, showed overall improvement in the iCS group, with a trend toward significance in subcomponents such as environmental autonomy.

Participant engagement was high: 97% of participants attended at least 21 of 24 sessions, with 64% attending all sessions. 95.3% of planned activities were completed, suggesting strong tolerability and acceptability of the intervention in this population.

Clinical Relevance and Implications

Although iCS did not produce statistically significant changes in global cognitive measures, the intervention yielded meaningful improvements in semantic memory and executive functioning—domains critical to communication, orientation, and independent living. The specificity of these effects underscores the potential of domain-targeted interventions in slowing functionally relevant decline in early AD.

Importantly, the observed stability in MMSE and ADAS-Cog may itself be of clinical interest, given the typically progressive nature of AD. In the absence of cognitive deterioration, modest improvements in targeted domains represent a favorable outcome.

The study’s modest sample size, limited follow-up period, and absence of biomarker confirmation of AD diagnosis limit generalizability. Moreover, although the intervention was culturally tailored and well-received, the lack of structured control for non-specific effects (e.g., therapist interaction) warrants cautious interpretation.

Nevertheless, this trial contributes to a growing evidence base supporting the incorporation of individualized cognitive stimulation into early Alzheimer’s disease care plans.

Reference:
Justo-Henriques SI, Lemos R, Rahmatpour P, et al. Effectiveness of individual cognitive stimulation on cognition in mild Alzheimer’s disease: a multicenter RCT. Psychogeriatrics. 2025;25(6):e70109. doi:10.1111/psyg.70109