Depression and mild cognitive impairment – Comorbidity and/or continuum?

Abstract

Introduction

Depression and mild cognitive impairment are common among the elderly. Half the patients with late-life depression also present some degree of cognitive decline, making the distinction between these conditions difficult.

Objectives

To conduct a database review in order to understand the relationship between these entities, and treatment approaches.

Aims

To create and implement clinical guidelines at our institution, to evaluate and treat elderly patients presenting with depression and mild cognitive impairment.

Methods

A PubMed database search using as keywords “late life depression”, “depression”; “cognitive impairment”; “mild cognitive impairment” and “dementia” between the year 2008 and 2015.

Results

Late-life depression and cognitive impairment are frequent among the elderly (10–20%). Depression is also common in the early stages of dementia decreasing as the cognitive decline progresses. The causal relationship between these entities is not well understood and some authors advocate a multifactorial model (genetic risk factors; neuroendocrine changes; vascular risk factors) and the cognitive impairment of said changes is dependent on the individual's cognitive reserve. Regarding treatment of depression in patients with cognitive impairment, most authors advocate a stepped approach with watchful waiting and then, if symptoms persist, the introduction of pharmacotherapy and psychosocial intervention.

Conclusions

The relationship between cognitive impairment and depression is still not clear and probably multifactorial. The diagnosis of depressive symptoms in patients with severe cognitive impairment can be difficult and most forms of pharmacological treatment in this population are not beneficial, making it important to carefully evaluate the benefits of introducing new medication.

Disclosure of interest

The authors have not supplied their declaration of competing interest.