A systematic review of the effects of non-pharmacological interventions in people with dementia and cognitive impairment

Abstract Background: Age-related cognitive decline, reducing a person’s abilities in areas of cognition, such as attention, memory, language, or visuospatial ability increasingly gains importance, as the human lifespan increases. When cognitive decline is pathologic and a form of dementia is diagnosed, interventions seek to recognize and counteract typical pathological patterns. On the one hand, pharmacological approaches, such as cholinesterase inhibitors and memantine are proven go-to solutions but are increasingly complemented by therapeutic and non-pharmacological interventions, such as cognitive behavioral therapy, physical and cognitive stimulation, psychosocial interventions, and in recent years even virtual-reality based interventions. Objective: Furthermore, as the objective of the study was to specifically analyze dementia in a certain age group, namely patients over 63 years, studies looking primarily at younger patients were excluded. As dementia has progressive characteristics, the studies were then grouped by diagnosis and the stage of progression, and the results were analyzed according to the reported effectiveness of the non-pharmacological interventions applied. Methods: For this review, three literature databases, namely PubMed, SCOPUS, and ERIC were scanned using a Boolean search with keywords related to different types of dementia, such as Huntington’s, Parkison’s, or vascular dementia. Following the approach outlined in the PRISMA statement, a multi-step process was then executed, reducing the 412 studies by deduplicating them, removing case studies, meta-studies, and, studies suffering from deficiencies, such as lacking a sufficient description of the non-pharmacological intervention applied. Results: Of the 412 studies encountered, only 11 (n = 1353 people) were found to be suitable for inclusion after removing meta-studies, and studies with an unsuitable population, or a lack of information regarding the chosen therapeutic approach. case studies or had an insufficient amount of information regarding the chosen sample. The reviewed studies indicated that physical stimulation had positive effects on cardiovascular disease in patients with dementia and positively correlated with an improvement of executive functions. Another important finding was psychosocial intervention, consisting of cognitive behavioral therapy (CBT) and cognitive rehabilitation improves general cognition, while no consistent results were obtained regarding the effects on specific areas of cognition. For both types of interventions, physical and mental stimulation, the length of the intervention positively correlated with the improvement of the scores. Regarding scores related to quality of life, measured for patients and caregivers alike, cognitive and occupational therapies were found to be a useful tool. Keywords: Dementia, Non-pharmacological intervention, Cognitive impairment, Cognitive rehabilitation, Systematic review, PRISMA statement.