Subthreshold depression needs a prime time in old age psychiatry? A narrative review of current evidence

Abstract

This study aims to carry out a narrative review, aiming to update the literature on subsyndromic depression (SD), which is the most prevalent depressive disorder in older adults, and no formal guidelines or consensus are dedicated to this topic. We carried out an electronic search for articles on SD. Relevant articles were retrieved from Pubmed, EMBASE and Web of Science using the search terms “subthreshold depression,” “prevalence,” “treatment” and “older adults” in several combinations. Original articles in English were included from inception to 1st March 2019. No clear consensus exists in the literature on its nosologic classification, diagnostic tools, causes, course, outcomes or management. SD diagnosis should base in depressive symptoms scales and DSM criteria. Treatment relies mainly on collaborative care and psychotherapy. SD is relevant in clinical practice and research in geriatric psychiatry. Given the negative outcomes and potential benefits of treatment, we recommend brief psychotherapy as first-line treatment and use of psychotropic agents in cases with greater severity and/or functional impairment in association with psychotherapy. SD can precede major depressive disorder, but it also may consist of a primary depressive disorder in older adults. Furthermore, adequate treatment of SD can prevent or reduce negative outcomes associated with depressive symptoms such as worsening of clinical comorbidities, loss of functionality, increased demand for health services, and increased mortality.