What is the aim of this study?

Childhood trauma, operationalized as emotional or physical neglect, or emotional, physical, or sexual abuse before the age of 18 years, is a common and major risk factor for the development and more severe course of depression in adulthood. A high prevalence of childhood trauma (about 46%) in adults with depression has been found, with even higher rates in patients with chronic depression.

Being a common and potent risk factor for depression, childhood trauma presents an opportunity to provide insights into personalized treatment planning, essential to reduce personal and societal burden. Meta-analytic findings of studies found that adults and adolescents with depression and childhood trauma were around 1-5 times more likely not to respond or remit after pharmacotherapy, psychotherapy, or combination treatment than adults and adolescents with depression but no childhood trauma. However, evidence on poorer treatment outcomes in patients with childhood trauma has not been definitive, with meta-analytic findings showing large between-study heterogeneity. Some primary studies showed that childhood trauma history predicted greater symptom improvement following solution-focused or psychodynamic psychotherapies compared to the absence of childhood trauma in adults with mood or anxiety disorders.

Further findings on treatment type suggest that psychotherapy (CBASP) alone or in combination with pharmacotherapy could be more beneficial than pharmacotherapy alone for individuals with chronic depression and childhood trauma but not for individuals without childhood trauma. But evidence hasn’t been consistent, with meta-analytic findings showing no significant differences between psychotherapy and pharmacotherapy treatment approaches when comparing patients with depression with and without childhood trauma.

The current meta-analysis aimed to examine whether adults with major depressive disorder, including chronic depression, and self-reported childhood trauma have more severe depressive symptoms before treatment, have less favourable baseline-to-post-treatment outcomes with active treatments, and are less likely to benefit from active treatments relative to a control condition. The authors also examined the influence of childhood trauma on dropout rates, the relative contribution of childhood trauma types to treatment outcomes, and the impact of potential effect modifiers such as treatment type or study quality.

What method was used?

The authors conducted a comprehensive meta-analysis, for which the protocol was registered at PROSPERO. A study-selection approach was used to identify journal articles in English on childhood trauma and adult depression treatment outcome, searching three bibliographical databases (PubMed, PsycINFO, and Embase) from Nov 21, 2013 (the search date of the latest meta-analysis) to March 16, 2022, and full-text screening studies in three sources of randomized clinical trials (RCTs): a database on psychological treatment, a network meta-analysis of pharmacological depression treatment, and a large-scale systematic review of clinical trials. Both RCTs and open trials comparing the efficacy or effectiveness of evidence-based interventions for acute treatment of adult depression for patients with and without childhood trauma were considered for inclusion. Two independent researchers extracted study characteristics. Group data for effect-size calculations were requested from study authors. The primary outcome was depression severity change from baseline to the end of the acute treatment phase, expressed as standardized effect size. Meta-analyses were done using random-effects models.

What were the results?

A total of 10,505 publications were examined overall, 61 studies met the inclusion criteria; 54 unique studies remained after removal of duplicates, of which 29 (54%) had authors who agreed to contribute their data and were included in the meta-analysis. This contributed to a maximum of 6830 participants (age range 18-85). More than half (4268 (62%) of 6830) of patients with major depressive disorder reported a history of childhood trauma. Despite having more severe depression at baseline, patients with childhood trauma benefitted from active treatment similarly to patients without childhood trauma history, with no significant difference in active treatment effects between individuals with and without childhood trauma, and similar dropout rates.

Findings did not significantly differ by childhood trauma type, study design, depression diagnosis, assessment method of childhood trauma, study quality, year, or treatment type or length, but differed by country. For example, North American studies showed larger treatment effects for patients with childhood trauma. Most studies had a moderate to high risk of bias, but the sensitivity analysis in low-bias studies yielded similar findings to when all studies were included.

What conclusions were made?

The current meta-analysis comprehensively examined the effect of childhood trauma on the efficacy and effectiveness of pharmacotherapy and psychotherapy for adult depression using data from 29 interventional studies and 6830 patients with major depressive disorder, including chronic depression. 62% of adults with depression in the intervention studies examined report a history of childhood trauma, suggesting that the prevalence of childhood trauma was slightly higher than in a previous meta-analysis (46%). Higher childhood trauma rates in the meta-analysis could be explained by a large number of studies focused on individuals with chronic or treatment-resistant depression, because childhood trauma rates are high (about 75%) in such groups.

The results suggested that childhood trauma did not significantly affect the efficacy of depression treatment, contrast with previous meta-analytic findings that observed poorer treatment response in individuals with depression and childhood trauma. These inconsistencies could be explained by differences in treatment outcome definition and publication and selection bias.

Contrary to previous studies, we found evidence that the symptoms of patients with major depressive disorder and childhood trauma significantly improve after pharmacological and psychotherapeutic treatments, notwithstanding their higher severity of depressive symptoms. Evidence based psychotherapy and pharmacotherapy should be offered to patients with major depressive disorder regardless of childhood trauma status.