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

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

Effect of Individual Cognitive Stimulation on Memory and Executive Functioning in Older Adults With Mild to Moderate Alzheimer's Disease: A Multicentre Randomised Controlled Trial

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.

older adults, cognitive function, memory, executive function, dementia, cognitive stimulation therapy, cognition, neurocognitive disorders, individual therapy, non-pharmacological therapy, randomised controlled trial, Alzheimer disease

Participants who meet the inclusion criteria will be randomly assigned to the intervention group receiving individual CS or to the control group receiving treatment as usual (participating in the activities previously established in their individual intervention plan). Participants in the intervention group will participate in two individual CS sessions per week for 12 weeks in addition to their treatment as usual. The sessions will include the same protocol in every participant site.

Participants in the control group will receive treatment/activities as usual, participating in the activities previously established in their individual intervention plan.

The intervention program will have 24 sessions (base scheme of 4 series of 6 sessions), lasting approximately 45 min and will be developed according to the following structure: - welcoming (greeting to the participant) (5 min); - orientation to reality (10 min); - main cognitive stimulation activity (25 min); - return to calm and evaluation of the session (5 min). The CS sessions will have an individual format and will be conducted by a professional with experience in CS and previously trained in this intervention. The intervention sessions will include several activities based on the CS principles, with evidence suggesting positive participant effects. The CS sessions will be carried out using material, developed by the principal investigator, in digital format (power point presentations). There will be no repetition of activities, and throughout the base CS program, the degree of difficulty of the exercises will be adjusted based on the dementia stage of the participant.

Cognitive functioning assessed by the Mini-Mental State Examination (MMSE), a gold standard screening tool for assessing global cognitive function. Scores range from 0 to 30, with higher scores indicating better cognitive functioning.

Change in cognitive functioning evaluated by the Mini-Mental State Examination (MMSE), a gold standard screening tool for assessing global cognitive function. Scores range from 0 to 30, with higher scores indicating better cognitive functioning.

Change in cognitive functioning evaluated by the Mini-Mental State Examination (MMSE), a gold standard screening tool for assessing global cognitive function. Scores range from 0 to 30, with higher scores indicating better cognitive functioning.

Cognitive functioning assessed through Alzheimer's Disease Assessment Scale - Cognitive Subscale (ADAS-COG)

Evaluates the severity of cognitive deficits in AD in the following domains: memory, orientation, language, praxis and constructive capacity. The total score in the Portuguese version of ADAS-Cog is composed of 11 subtests in the cognitive part and varies between 0 (better performance) and 68 points (worse performance), i.e., higher scores equals better performance.

Change in cognitive functioning assessed through Alzheimer's Disease Assessment Scale - Cognitive Subscale (ADAS-COG)

Evaluates the severity of cognitive deficits in AD in the following domains: memory, orientation, language, praxis and constructive capacity. The total score in the Portuguese version of ADAS-Cog is composed of 11 subtests in the cognitive part and varies between 0 (better performance) and 68 points (worse performance), i.e., higher scores equals better performance.

Change in cognitive functioning assessed through Alzheimer's Disease Assessment Scale - Cognitive Subscale (ADAS-COG)

Evaluates the severity of cognitive deficits in AD in the following domains: memory, orientation, language, praxis and constructive capacity. The total score in the Portuguese version of ADAS-Cog is composed of 11 subtests in the cognitive part and varies between 0 (better performance) and 68 points (worse performance), i.e., higher scores equals better performance.

The MAT is used to assess memory function. It is an easy and quick instrument that assesses five memory domains: temporal orientation, encoding, semantic memory, free recall, and cued recall. Total scores range from 0 to 50, with higher scores indicating better memory. It has good psychometric properties and is highly sensitive to mild cognitive decline.

The MAT is used to assess memory function. It is an easy and quick instrument that assesses five memory domains: temporal orientation, encoding, semantic memory, free recall, and cued recall. Total scores range from 0 to 50, with higher scores indicating better memory. It has good psychometric properties and is highly sensitive to mild cognitive decline.

The MAT is used to assess memory function. It is an easy and quick instrument that assesses five memory domains: temporal orientation, encoding, semantic memory, free recall, and cued recall. Total scores range from 0 to 50, with higher scores indicating better memory. It has good psychometric properties and is highly sensitive to mild cognitive decline.

FCSRT is a verbal learning and memory test that allows prompting the encoding and retrieval conditions by using semantic cues on learning and recall trials. It is composed of 16 semantically categorised, unrelated items/words.

FCSRT is a verbal learning and memory test that allows prompting the encoding and retrieval conditions by using semantic cues on learning and recall trials. It is composed of 16 semantically categorised, unrelated items/words.

FCSRT is a verbal learning and memory test that allows prompting the encoding and retrieval conditions by using semantic cues on learning and recall trials. It is composed of 16 semantically categorised, unrelated items/words.

FAB assesses executive functions such as abstract thinking, mental flexibility, motor programming, interference sensibility, inhibitory control and environmental independence. Scores range between 0 - 18 points with higher scores indicating better cognitive function.

FAB assesses executive functions such as abstract thinking, mental flexibility, motor programming, interference sensibility, inhibitory control and environmental independence. Scores range between 0 - 18 points with higher scores indicating better cognitive function.

FAB assesses executive functions such as abstract thinking, mental flexibility, motor programming, interference sensibility, inhibitory control and environmental independence. Scores range between 0 - 18 points with higher scores indicating better cognitive function.

TMT is one of the most widely used instruments in clinical and experimental neuropsychology. It is very sensitive to identify cognitive impairments, measuring simple motor and spatial skills, basic sequencing skills, mental flexibility, selective attention, visuo-perceptual skills, motor speed, and executive functions. Higher scores indicate greater impairment.

TMT is one of the most widely used instruments in clinical and experimental neuropsychology. It is very sensitive to identify cognitive impairments, measuring simple motor and spatial skills, basic sequencing skills, mental flexibility, selective attention, visuo-perceptual skills, motor speed, and executive functions. Higher scores indicate greater impairment.

TMT is one of the most widely used instruments in clinical and experimental neuropsychology. It is very sensitive to identify cognitive impairments, measuring simple motor and spatial skills, basic sequencing skills, mental flexibility, selective attention, visuo-perceptual skills, motor speed, and executive functions. Higher scores indicate greater impairment.

The sociodemographic questionnaire was designed specifically for this study. It gathers information about the participants' gender, age, marital status, educational level, care and support services that the participant attends, medical comorbidities (including cognitive ones), and pharmacological treatment. It will be administered to all participants.

Adherence to the intervention and dropouts will be assessed using a session form, designed specifically for this study, completed by the technician after each session, tracking the attendance and mood/behaviour of the participants throughout the intervention sessions.

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.