Screening for depression among the general adult population and in women during pregnancy or the first-year postpartum: two systematic reviews to inform a guideline of the Canadian Task Force on Preventive Health Care
Authors: Beck Andrew , Hamel Candyce , Thuku Micere , Esmaeilisaraji Leila , Bennett Alexandria , Shaver Nicole , Skidmore Becky , Colman Ian , Grigoriadis Sophie , Nicholls Stuart Gordon , Potter Beth K. , Ritchie Kerri , Vasa Priya , Shea Beverley J. , Moher David , Little Julian , Stevens Adrienne 
Published: August 2022

Abstract
Background
Depression affects an individual’s physical health and mental well-being and, in pregnant and postpartum women, has specific adverse short- and long-term effects on maternal, child, and family health. The aim of these two systematic reviews is to identify evidence on the benefits and harms of screening for depression compared to no screening in the general adult and pregnant and postpartum populations in primary care or non-mental health clinic settings. These reviews will inform recommendations by the Canadian Task Force on Preventive Health Care.

Methods
We searched MEDLINE, Embase, PsycINFO, CINAHL, and the Cochrane Library using a randomized controlled trial filter, where applicable, October 4, 2018, and updated to May 11, 2020. We also searched for gray literature (e.g., websites of organizations of health professionals and patients). Study selection for depression screening trials was performed first on title and abstract, followed by full-text screening. Data extraction, assessment of the risk of bias using the Cochrane risk of bias tool, and application of Grading of Recommendations Assessment, Development and Evaluation were performed by one reviewer and validated by a second reviewer.

Results
A total of three trials were included. All three trials were included in the general adult review, while one of the three trials was included in the pregnant and postpartum review. We did not pool results due to substantial differences between studies and high risk of bias. In the general adult review, the first trial (n = 1001) evaluated whether screening for depression in adults with acute coronary syndrome compared to usual care improves health-related quality of life, depression symptoms, or harms of screening at 6, 12, and 18 months. There were little to no differences between the groups at 18 months for the outcomes. The second trial included adults (n = 1412) undergoing initial consultation for osteoarthritis, evaluated for depression and general health (mental and physical) after initial consultation and at 3, 6, and 12 months. The physical component score was statistically significantly lower (worse health) in the screened group at 6 months; however, this difference was not significant at 3 or at 12 months. There were no clinically important or statistically significant differences for other outcomes between groups at any time. The third trial (included in both reviews) reported on 462 postpartum women. At 6 months postpartum, fewer women in the screening group were identified as possibly depressed compared to the control group (RR 0.59, 95% confidence interval (CI) 0.39 to 0.89) and mean EPDS scores were also statistically significantly lower in the screened group (standardized mean difference 0.34 lower (95% CI 0.15 to 0.52 lower)). All other outcomes did not differ between groups at follow-up. There were serious concerns about the cut-offs used for the questionnaire used to screen, diagnostic confirmation, selective outcome reporting, and the reported magnitude of effects.

Discussion
There are limitations of the evidence included in the reviews. There was moderate certainty in the evidence from one trial that screening for depression in the general adult population in primary care or non-mental health clinic settings likely results in little to no difference on reported outcomes; however, the evidence was uncertain from the other two included trials. The evidence is very uncertain about the effect of screening for depression in pregnant or postpartum women in primary care or non-mental health clinic settings. Well-conducted and better-reported trials are needed that meet the screening trial criteria used in this review.

Systematic review registration
Both protocols have been registered in the International Prospective Registry of Systematic Reviews (PROSPERO) [adult: CRD42018099690; pregnancy and postpartum: CRD42018099689﻿] and published (https://systematicreviewsjournal.biomedcentral.com/track/pdf/10.1186/s13643-018-0930-3).