This research aims to evaluate the ability of individual reminiscence therapy (RT), using a simple reminiscence format, to improve the overall cognitive function, memory, emotional status and quality of life (QoL) of older adults with neurocognitive disorders (NCD) attending social care and support services. A multicentre randomised controlled trial (RCT) is proposed in Azores archipelago with repeated measures (pre-intervention, post-intervention and follow-up). Intervention group will hold 26 individual RT sessions, twice a week for 13 weeks. Control group participants will maintain their treatment as usual. Make a subsample analysis of the main clinical diagnoses, and compare the results of sample and subsample with a previous study that had the same intervention protocol.

Neurocognitive disorder (NCD) is one of the main causes of disability among older adults and its prevalence is increasing due to the ageing of the population. It is estimated that globally, neurocognitive disorders affect 44.35 million people and it is expected that by the year 2050 the number of those affected worldwide will triple up to 135.46 million.

The absence of an effective pharmacological treatment that halts or delays the development of the disease has aroused interest in non-pharmacological therapies (NPT) as a complement to pharmacological treatment that can improve the quality of life of people with neurocognitive disorders. One of the most researched NPT and with the greatest tradition in this field is Reminiscence Therapy (RT).

RT implies the discussion of past activities, events and experiences, usually with the help of triggers (e.g., photographs, home objects and other familiar items from the past, music, any object or stimulus) that serve to stimulate memories. In its application to dementias, RT is based on the fact that the memory deficit of people with dementia implies that they are able to remember events from their past life, especially from childhood to early adulthood, but not newer facts. It focuses on preserved capacities and memories, promotes communication and enables the person to connect with his past and recover his sense of personal identity. In this way, the RT can be understood as an intervention on the edge of those of cognitive orientation and those centred on emotion, with potential interactive effects on autobiographical memory and psychological well-being.

In simplified form, there are at least two approaches to RT. The first approach as a "life review" where participants are guided through significant experiences of their biography trying to give meaning to their lives. This type of RT is more structured and is usually conducted in an individual format. It may involve the production of "life books". This approach is considered to have an integrative function aimed at achieving a sense of validation, coherence and reconciliation with one's past. Another approach that call general or simple reminiscence, implies the stimulation of autobiographical memory during conversations on specific themes of the past (e.g, holidays, food and drink, work) using stimulus to trigger memories. It has been described as an unstructured autobiographical memory narration. This reminiscence format can be conducted both individually and in groups and promotes communication between participants who share their memories and stories.

In either format that RT is applied on, the introduction of triggering stimulus (e.g., photographs, music, old objects) to help memory is considered fundamental. These triggers can be generic, reflecting common experiences in the lives of people relevant to their age group (e.g., a school manual can serve as a reminder of the experience during their school stage), or specific, with stimulus related to the person's own experiences (e.g., photographs of an important vital event such as their wedding day or a journey during their youth).

As for the effectiveness of RT, according to a recent review by Cochrane, there is some evidence on its positive effects on cognition, QoL, communication and possibly on the mood of people with dementia, even if the benefits are small. Despite the distinction between the two different approaches to RT (general reminiscence vs. life history), the therapy modality does not seem to be as important to achieve positive effects as the individual or group format of the sessions and the context in which the intervention is administered (people living in the community or institutionalised).

In particular, according to the results of the review study, the RT seems to be able to generate a small benefit on cognitive function immediately after the intervention, although it usually does not continue after a longer follow-up period. Regarding the administration format, the individual RT seems slightly superior in its effects on cognition both immediately and after a follow-up period. In any case, its effects seem comparable to those of other cognitive stimulation modalities.

As for the effect of RT on quality of life (QoL), an individual RT study based on life review, showed an improvement in Qol-AD. The effects with a group modality do not seem consistent, showing little or no effect on QoL, although the key factor may be the context of application (community vs. institution), with better group RT results in institutionalised patients.

In a multicentre study conducted in Portugal with older adults with neurocognitive disorders, in individual format, there was a significant effect on the overall cognition, memory and QoL of the participants.

Group RT was associated with a likely effect on communication both after the intervention and in the follow-up. This effect was not replicated in the individual RT, with uncertain results.

Finally, despite the evidence on the effect of RT on the mood of elderly people without dementia, in the case of people with dementia only a small effect on mood was found for those participating in individual RT. In the portuguese multicentre studies there were no significant differences in depressive symptomatology.

Based on the above, this research proposal aims to evaluate the ability of individual RT within a general reminiscence format, to improve overall cognitive function, in particular memory, emotional state (depression and anxiety) and QoL of older adults with neurocognitive disorders attending social care and support services in the Azores archipelago.

It is proposed to evaluate the efficacy of the intervention in the endpoint assessment and the duration of the effects at three months follow-up. Furthermore, an analysis of results based on the diagnosis of the participants is proposed for those diagnoses with sufficient representation in the sample (more than 20 cases in each group). Additionally, it is proposed to analyze the factors that predict the response to the intervention (responder analysis). Finally, the results of this study will be compared and can be analyzed together with those of a previous study that used the same individual RT program and the same experimental design (clinicaltrials.gov ID: NCT04047238).

Inclusion Criteria:

• Having a formal diagnosis of a neurocognitive disorder according to Diagnostic and Statistical Manual of Mental Disorders, fifth edition [DSM-5] criteria (participants diagnosis will be confirm in their health records at the institution).
• Having delivered the informed consent form, duly completed and signed, after prior information.
• Being able to communicate and understand.
• Possibility of gathering information about the participant's life history through family members or usual caregivers, using the socio-family questionnaire designed for that purpose.
• Being 65 years of age or older.
• Being a native Portuguese speaker.
• Regularly attending an institution that provides social care and support services for older adults (including people living in long-term care centres, people attending day and social centres and people receiving home support services).

Exclusion Criteria:

• Suffering from an acute or severe illness that prevent participation in the intervention sessions.
• Severe sensory and physical limitations that prevent participation.
• Low level of consciousness and minimal attention span.
• Presence of severe neuropsychiatric symptoms, such as agitation, psychosis, severe depressive and anxiety symptoms, apathy, or presence of uncontrolled delirium that prevent participation in the sessions.
• Traumatic life history or marked by adverse events that discourage participation in RT sessions; history of adverse reactions during RT sessions or similar activities.
• Have a serious or total functional dependence (assessed through the Barthel index).