Locus of Control among People with Dementia - associations with dementia severity, cognitive function and depressive symptoms

Abstract

Dementia is characterized by cognitive dysfunction, behavioural and psychological changes, and a gradual inability to perform everyday activities. Depression is a common comorbidity. The psychological construct locus of control can affect how a person cope with stressors and may thus inform our ability to help people with dementia cope with their difficulties.

Using observational data, the aim of this thesis was to examine locus of control among people with dementia by examining its association with dementia severity, cognitive function, and depressive symptoms.

First, we synthesized current knowledge regarding control belief constructs among people with dementia. 18 eligible papers were found, and self-efficacy was the most examined construct. The studies were varied, with no clear overall conclusion, but none reported difficulties with measuring control beliefs in this population.

Next, we examined the applicability of a specific locus of control scale for people with dementia. Age, education, and cognitive function affected the ability to complete the scale, but cognitive function did not appear to affect reliability. Further, having a more external locus of control was associated with depression.

Then we examined the association between locus of control and depressive symptoms among people with dementia, both cross-sectionally and prospectively. Locus of control was associated with depressive symptoms at both time points. When examining changes over one year, most participants became either more or less externally oriented. Participants who became more external showed more signs of dementia progression, however had a decrease in the severity of depressive symptoms.

It appears valuable to examine locus of control among people with dementia, but cognitive impairment can affect the ability to complete such complex scales. Apart from completion, dementia severity and cognitive function were not associated with locus of control, however depressive symptoms were.