P-6: Mood Disorder in Older Adults: A Proposed Model of Relationship between the Disease and Disability
Dr. Sunny Luthra
Atul Sunny Luthra*,
Mood disorder in older adults (MDOA) is managed as a chronic medical disease with emphasis on optimal remission of the index episode and greater emphasis on recurrence prevention. The level of disability associated with it is one of the highest in comparison to other chronic medical illnesses.
Review of the literature identified three of the established determinants impacting functioning in MDOA: 1) amotivational states 2) intellectual dysfunction 3) psychological coping. Resident Assessment Inventory (RAI) is a standardized tool administered to all patients admitted to Program for Older Adults (POA), Homewood Health Centre. Embedded in this inventory are several subscales which reflect specific symptoms and functional factors. Three subscales were identified to suitably reflect the individually identified determinants of disability in MDOA: the “Withdrawal/ Negative Symptom Scale” accurately captures amotivational states, the “Cognitive Performance Scale” accurately captures intellectual dysfunction, and the “Depression” and “Anxiety Rating Scales” capture psychological function. Three subscales to capture functioning were: “Interpersonal Conflict/ Social Function Scale,” the “Activities of Daily Living Hierarchy Scale,” and “Activities of Daily Living Instrumental Scale.” Based on the outcomes of patients with MDOA, a dynamic interactional model amongst these “independent” and “dependent” variables was established as a way of proposing a new model to understand the relationship between disease and disability.
Three different multiple linear regression analyses were performed on the patients admitted to POA during the interval 2012 to 2015. They were managed in with this new innovative approach to tailor pharmacological treatment with the changing phenotype of the ‘index episodes’. 120 patients were included in the analysis.
We first computed change scores for all embedded subscales in RAI to track a dynamic relationship between admission and discharge scores. Next, we allocated the ‘Independent’ (Negative Symptom Scale, Depression Rating Scale, Anxiety Scale and Cognitive Performance Scale) and ‘Dependent’ (Interpersonal Conflict Scale, Activities of Daily Living Hierarchy Scale, Activities of Daily Living Instrumental) variables relevant to the model. We used ‘multiple linear regression analysis’ to identify statistically significant relationships amongst these variables to establish the model.
The first hypothesis evaluated the relationship between the four ‘independent’ variables with one dependent variable of interpersonal conflict/social functioning. The second hypothesis evaluated the relationship between depression (positive relationship) and anxiety (negative relationship) and interpersonal conflict/social function. The third hypothesis evaluated the relationships between four independent variables and the dependent variable of Activities of Daily Living Hierarchy (ADLH). The fourth hypothesis evaluated the relationship between the 4 independent variables and the dependent variable of Activities of Daily Living Instrumental (ADLI).
Multiple linear regression was performed and found a statistically significant model where changes in Cognitive Performance (positive relationship) predicted changes in ADLI. That means that Depression, Anxiety and Negative Symptoms did not significantly influence ADLI
Multiple linear regression was performed and found a statistically significant model where changes in Negative Symptoms (positive relationship) predicted changes in ADLH. That means that Depression, Anxiety and Cognition did not significantly influence ADLH.
Multiple linear regression was performed and found a statistically significant model where changes in Depression (positive relationship) and changes in Anxiety (negative relationship) predicted changes in Interpersonal Conflict. That means that Negative Symptoms and Cognition did not significantly influence Interpersonal conflict.
Motivational drives influence ADLs, executive function influences IADLs, and psychological coping influences social function. Optimal return to function must include individualized treatment interventions tailored to each of these determinants.