Open AccessThis article is licensed under a Creative Commons Attribution 4.0 International License, which permits use, sharing, adaptation, distribution and reproduction in any medium or format, as long as you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons licence, and indicate if changes were made. The images or other third party material in this article are included in the article's Creative Commons licence, unless indicated otherwise in a credit line to the material. If material is not included in the article's Creative Commons licence and your intended use is not permitted by statutory regulation or exceeds the permitted use, you will need to obtain permission directly from the copyright holder. To view a copy of this licence, visit http://creativecommons.org/licenses/by/4.0/. The Creative Commons Public Domain Dedication waiver (http://creativecommons.org/publicdomain/zero/1.0/) applies to the data made available in this article, unless otherwise stated in a credit line to the data.
Major depressive disorder is common, debilitating, and affects feelings, thoughts, mood, and behaviors. Childhood and adolescence are critical periods for the development of depression and adolescence is marked by an increased incidence of mental health disorders. This protocol outlines the planned scope and methods for a systematic review update that will evaluate the benefits and harms of screening for depression in children and adolescents.
This review will update a previously published systematic review by Roseman and colleagues. Eligible studies are randomized controlled trials (RCTs) assessing formal screening in primary care to identify children or adolescents not already self-reporting symptoms of, diagnosed with, or treated for depression. If no or only a single RCT is available, we will consider controlled studies without random assignment. Studies of participants with characteristics associated with an elevated risk of depression will be analyzed separately. Outcomes of interest are symptoms of depression, classification of major depressive disorder based on a validated diagnostic interview, suicidality, health-related quality of life, social function, impact on lifestyle behavior (e.g., substance use, school performance, lost time at work, or school), false-positive results, overdiagnosis, overtreatment, labeling, and other harms such as those arising from treatment. We will search MEDLINE, Embase, PsycINFO, CINAHL, the Cochrane Library, and grey literature sources. Two reviewers will independently screen the titles and abstracts using the liberal accelerated method. Full-text screening will be performed independently by two reviewers using pre-specified eligibility criteria. Data extraction and risk of bias assessments will be performed independently by two reviewers. Pre-planned analyses, including subgroup and sensitivity analyses, are detailed within this protocol. Two independent reviewers will assess and finalize through consensus the certainty of evidence using the Grading of Recommendations Assessment, Development and Evaluation (GRADE) approach, and prepare GRADE evidence profiles and summary of findings tables for each outcome of interest.
The systematic review will provide a current state of the evidence of benefits and harms of depression screening in children and adolescents. These findings will be used by the Canadian Task Force on Preventive Health Care to inform the development of recommendations on depression screening.
The online version contains supplementary material available at 10.1186/s13643-020-01568-3.
Keywords: Depression, screening, systematic review, child, children, adolescent, youthMajor depressive disorder (MDD) is a common, debilitating mood disorder characterized by negative feelings, thoughts, and behaviors that causes significant impairment in social, occupational and educational functioning, and quality of life, and is related to an increased risk of suicide and death [1, 2]. During the transition from childhood to adolescence, there is an increase in prevalence of some psychiatric disorders including depression [3]. This transition involves physical, psychological, and emotional changes typical of this developmental period, which may increase an individual’s sensitivity and reactivity to stress exposure [4, 5]. As with the adult population, diagnoses of depressive episodes in children and adolescents are established by one of the two commonly used diagnostic classification systems for psychiatric diagnoses, the Diagnostic and Statistical Manual of Mental Disorders, Fifth Edition (DSM-5) [6], and International Classification of Diseases, 10 th Revision (ICD-10) [7]. Each diagnostic system provides a minimum number of criteria that must be met over a 2-week period for an episode to be considered a depressive episode. Also, the DSM-5 includes further criteria to specifically define MDD for children and youth [6]. Symptoms of irritability can be considered in place of depressed mood, and a failure to meet expected weight gain can be considered instead of weight loss (see Additional file 1).
From the 2014 Ontario Child Health Study, the 6-month prevalence of possible major depressive episodes (MDE) was 1.1% for children (4- to 11-year-old) and 5.2% or 7.5% for adolescents (12- to 17-years-old) based on parent or adolescent report, respectively [8]. In pooled estimates from the Canadian Community Health Survey, a series of cross-sectional surveys from 2000 to 2014, 5.5% of 12- to 19-year-olds reported experiencing MDE-like episodes in the past year, with little change in prevalence from 2000 to 2014 [9]. Rates were higher among females and among those aged 15 to 19 years (10.1% for females; 4.1% for males) compared to those aged 12 to 14 years (4.1% for females; 0.6% for males) [9], with similar findings supported by other literature [10–12].
The burden of depression is high among children and adolescents. Unipolar depressive disorders (i.e., major depressive episode, dysthymia) are a leading cause of years lost to disability among both the 10- to 14-year-old and 15- to 19-year-old age groups [13, 14]. Poor long-term social outcomes are also a consequence of depression in adolescence. Those with depression are at an increased risk of leaving secondary school, unemployment, early pregnancy, and parenthood [15]. As well, they have a lower likelihood of entering post-secondary education [15]. Depression with onset in childhood and adolescence can continue into adulthood, posing a burden on individuals, families, and communities [15–18]. A recent systematic review found that adolescents who suffer from depression have around 2.5 (2.78 [95% CI 1.97, 3.93]) times the odds of developing depression in adulthood compared with adolescents without depression [16]. Additionally, those who suffer from depression in adolescence are at an increased risk for suicidal ideation, attempts, and completion in adulthood [19–21].
There are several risk factors associated with depression in children and adolescents. As shown above, females are at a higher risk, particularly in adolescence, with the difference between sexes becoming smaller later in adulthood [12, 22]. A family history of depression and exposure to adverse events such as illness or death of a family member, physical or sexual abuse, are also strong risk factors [23, 24]. Parental behaviors associated with an increased risk include aversive behaviors toward the child or adolescent (e.g., criticism, punishment, and conflict), lack of autonomy given to the child or adolescent, lack of warmth, inconsistent parental discipline, and parental over-involvement [25]. Other influential factors include aspects related to the school environment such as bullying, low connectedness with peers and teachers [26, 27], poor academic achievement [28], learning disabilities (e.g., attention deficit hyperactivity disorder, dyslexia) [29–31], and community environment factors such as safety, ethnicity, and prevalence of discrimination [32]. Additional risk factors include substance abuse (e.g., alcohol, tobacco, cannabis, other illicit drugs), poor sleep, screen time, unhealthy diet, and weight problems [33–35].
A screening program for depression must identify symptomatic disease that would not otherwise be reported (e.g., by spontaneous patient self-report, parent/caregiver report, or clinical inquiry). If effective, screening for depression would be expected to lead to interventions that improve future health outcomes in those who otherwise would not have been identified [36]. However, as noted by Cosgrove et al. [37], without evidence on the benefits and harms of screening, there are several assumptions that are questionable in the case of depression screening. First, unlike other disorders, depression does not have a detectable asymptomatic early stage. It manifests as one or more discrete episodes and many patients remit after an initial episode. Screening tools rely on identifying symptoms of depression itself and therefore can only be effective at early detection if the use of the tool prompts consideration of whether or not symptoms of depression are present. Second, there is currently little evidence that adding screening questionnaires to primary care reduces depressive symptoms. Third, optimal treatment for screen-detected depression is not clear. Most people identified as depressed via screening will have mild symptoms that may resolve without intervention. Many are treated with antidepressant medications. However, the majority of antidepressant medications have not been shown to be as effective in adolescents as in adults, may increase risk for suicidality, and may be even less likely to be effective for the mild cases likely overrepresented in patients identified through screening questionnaires [38, 39]. Psychological therapies are a reasonable option to medications with some positive effects [40, 41].
In considering the potential benefits and harms of screening, the proper design of trials is paramount [42, 43]. Experts have criticized previous systematic reviews on depression screening that have not explicitly defined the characteristics of screening trials to isolate the effect of screening from, for example, diagnostic suspicion by patients or clinicians [44, 45]. For example, a screening trial should separate the effect of screening from the effect of providing additional treatment resources not otherwise available. Since screening programs should only identify previously unrecognized cases, a screening trial should also exclude patients already diagnosed or under care for depression [42]. Accordingly, we have specified criteria that would need to be met to reduce selection and confounding bias in the inclusion of evidence. These are detailed in the “Methods” section.
In 2005, the Canadian Task Force on Preventive Health Care (“Task Force”) published recommendations on screening for depression in the adult population as well as children and adolescents. The Task Force guideline concluded that there was insufficient evidence to recommend either for or against depression screening in children and adolescents [46]. In 2016, the U.S. Preventive Services Task Force (USPSTF) updated their 2009 guideline and systematic review and recommended routinely screening for depression in adolescents (age 12 to 18 years) in primary care settings “with adequate systems in place to ensure accurate diagnosis, effective treatment, and appropriate follow-up,” but not in children (aged ≤ 11 years) due to insufficient evidence [47, 48]. The USPSTF recommendation for screening relied on indirect and linked evidence that screening instruments for depression can accurately identify MDD in adolescents and that treatment of MDD detected through screening in adolescents is associated with moderate benefit. However, this was not based on screening trials, as no trials were identified that directly assessed the effects of screening compared with no screening [48]. The recommendation was based on eight “fair- “or “good-quality” placebo-controlled intervention trials examining the effectiveness of antidepressants, psychotherapy, and collaborative care interventions (e.g., the Massachusetts Child Psychiatry Access Project, an inter-professional collaboration among primary care providers and mental health specialists) for children and adolescents with MDD. They found that one trial had shown effectiveness with fluoxetine as well as combined fluoxetine and cognitive behavioral therapy. Furthermore, one of the two escitalopram trials and the one collaborative care trial had demonstrated benefits. The USPSTF considered the evidence on screening test accuracy and treatment of MDD adequate and the harms of pharmacotherapy treatment to be minimal if patients were closely monitored. Similar to the USPSTF, the Guidelines for Adolescent Depression in Primary Care (GLAD-PC) Steering Group updated their 2007 systematic literature review and guideline [49] and found no evidence comparing screening to no screening or usual care in primary care settings [50]. They relied upon indirect evidence surrounding the validity and feasibility of screening tools and the feasibility and effectiveness of treatment for individuals with depression. GLAD-PC recommended annual screening for depression in adolescents (ages 12 and older) based on psychometric data on depression screening tools as well as research on screening issues (e.g., whether screening is occurring and whether screening impacts follow-up procedures or treatment to the specifics of screening). They considered that early identification and treatment of adolescent depression is important because of the high prevalence of depression and its persistence, its potential occurrence during a crucial brain development period, and the potential consequences with transition into adulthood. Among those with depression risk factors ages 10 to 21 years, GLAD-PC recommended not only annual screening but also more frequent targeted screening (i.e., systematically monitoring individuals over time for the development of a depressive disorder) during other health care visits. Their justification for this recommendation was that these individuals are likely to experience future depressive episodes and those who are not diagnosed with depression but report high scores on the screening tools may be at risk for depression within 6 months [50].
There are inconsistencies among the current screening guidelines reviewed above, notably their reliance on indirect evidence and the failure to include RCTs where the potential impacts of screening and treatment are clearly separated. A recent review by Roseman and colleagues [51] was selected by the Task Force working group as an appropriate review to update but with modifications, such as also addressing patients that may have an elevated risk of depression, including other outcomes of relevance to decision making, other study design filters, and expanding the search approach. This review update will provide a current assessment of the evidence for the Task Force guideline recommendations.
The Task Force is undertaking a systematic evaluation of the literature to inform its upcoming guideline recommendation on depression screening in children (6 to 11 years old) and adolescents (12 to 17 years old) in primary care. A depression working group of task force members (i.e., guideline panel) and external clinical experts was formed. The development of the topic, refinement of the key questions, and the structured Population, Intervention, Comparator, Outcome, Study Design (PICOS) eligibility framework involved discussions among the working group and members of the Public Health Agency of Canada (PHAC) and the Ottawa Evidence Review and Synthesis Centre (ERSC). For more information on the process of topic development and selection of working group members and clinical experts, please refer to the Task Force Procedure Manual (https://canadiantaskforce.ca/methods/).
The purpose of this systematic review is to examine the evidence on screening for depression in children and adolescents within primary care, and the findings will be used by the Task Force to inform the development of guideline recommendations. This protocol outlines the methodological process for performing a review update of Roseman et al. (2017) [51].
Our systematic review update will be guided by the following key questions (KQ):
KQ1: What are the benefits and harms of screening for depression in children (6 to 11 years old) and adolescents (12 to 17 years old) in primary care or other non-mental health clinic settings?
KQ1a: What are the benefits and harms of screening for depression in children (6 to 11 years old) and adolescents (12 to 17 years old) in primary care or other non-mental health clinic settings for patients targeted because they have characteristics that may suggest elevated risk of depression?
Figure Figure1 1 presents an analytic framework of screening for depression in children and adolescents in primary care and the relevant health outcomes.