Late-onset depression: A risk factor for major neurocognitive disorder?

Depression and dementia/major neurocognitive disorder (MNCD) are the most common psychiatric morbidities in elderly people. To assess whether late-onset depression (LOD)—defined as onset of first major depressive episode occurring at or above 50 years—and other socio-demographic and clinical variables are risk factors for MNCD in those aged 60 years or above. A hospital-based, case-control study was undertaken, with 170 cases of MNCD and 172 controls without MNCD (as assessed using Malayalam adaptation of Addenbrooke's Cognitive Examination). Participants were evaluated for LOD using Structured Clinical Interview for Diagnostic and Statistical Manual for Mental Disorders-Fourth Edition-Text Revision- Research Version. LOD had a crude OR of 1.22 (95% CI = 0.75–2.00). On univariate analysis, age group ≥80 years, family history of MNCD, hypertension, hyperlipidaemia, movement disorder, normal pressure hydrocephalus and history of treatment for depression were found to be significant risk factors and low income a significant protective factor. After adjusting for socio-demographic and clinical variables using multiple logistic regression, LOD was not found to be a significant risk factor for MNCD (adjusted OR = 0.62, 95% CI = 0.32–1.20). Age ≥80 years, female sex, history of treatment for depression, family history of MNCD, hyperlipidaemia and movement disorders were significant risk factors for MNCD, in the model. LOD does not increase the risk of MNCD significantly in elderly population. Increasing age, female sex, a positive family history of MNCD and medical comorbidities like hyperlipidaemia and movement disorders were significant risk factors along with a history of treatment for depression.