Effect of Individual Cognitive Stimulation on Memory and Executive Function in Older Adults With Alzheimer's Disease

This multicentre study, with a randomised controlled repeated measures experimental design, will be conducted in several Portuguese institutions, which provide care and supportive services for older adults diagnosed with mild or moderate Alzheimer's disease (AD), with an aim to assess the effect of individual cognitive stimulation (CS) on memory and executive functioning. Participants in the intervention group will attend 24 individual CS sessions, twice weekly for 12 weeks. Participants in the control group will complete their usual routines without any activity restrictions.

Neurocognitive disorders (NCD) currently affect around 55 million people worldwide and expected to increase to 78 million by 2030 and 139 million by 2050, with Alzheimer's disease (AD) potentially accounting for 60-70% of dementia cases. Dementia is a syndrome, generally chronic or progressive in nature, that causes deterioration of cognitive function, particularly memory and executive functions, beyond what is expected in normal aging. However, there is evidence that in the early stages of NCD, people can learn and improve their cognitive functions through interventions such as CS. CS is a psychosocial intervention and a non-pharmacological therapy recommended by international practice guidelines for people with mild-to-moderate stage AD. However, it is also important to investigate whether NCD generates new skills or only preserves acquired skills, given that AD manifests initially and notably with deficits in memory and learning, sometimes accompanied by deficits in executive functions. Testing the effectiveness of CS by recruiting a representative sample from several Portuguese districts and using a CS programme with detailed and comprehendible content, may elicit relevant evidence in clinical practice, contribute to the development of social development programs and initiatives to ensure social protection and inclusion, promote recurrent therapeutic interventions in Portuguese institutions with provide care and supporting services for older adults with dementia, and strengthen research on non-pharmacological therapies. Thus, this multicentre, randomised controlled study is essential to analyse the effects of the individual CS on global cognitive function and specific cognitive domains (e.g., executive functioning, memory) in older adults with mild or moderate AD.

Eligibility Criteria:
Inclusion Criteria:

* Age 65 or over.
* Receive care and support services for older adults for at least three months.
* Alzheimer's disease, according to the criteria of the Diagnostic and Statistical Manual of Mental Disorders, 5th edition.
* Ability to communicate and understand.
* Native speakers of Portuguese.
* To have given informed consent for the project, duly completed and signed, after previous information.
* Total scores between 10 and 24 points on the Mini Mental State Examination.

Exclusion Criteria:

* Cannot read and write.
* Severe sensory and physical limitations and/or an acute or serious illness preventing participation in the CS sessions.
* Evidence of aggressive and disruptive behaviour, as indicated by the reference technicians of the institution to which the participant is linked.
* Consumption of psychoactive substances, taking neuroleptics and/or antipsychotics in the last two months.