Adults with major depressive disorder who have a history of childhood trauma experience symptom improvement after pharmacotherapy, psychotherapy, or combination treatment. The results of a new study, published in The Lancet Psychiatry, suggest that contrary to current theory, these common treatments for major depressive disorder are effective for patients with childhood trauma.

Childhood trauma (defined as emotional/physical neglect or emotional/physical/sexual abuse before the age of 18) is known to be a risk factor for the development of major depressive disorder in adulthood, often producing symptoms that are earlier onset, longer lasting/more frequently recurring, and with increased risk of morbidity. Previous studies have suggested that adults and adolescents with depression and childhood trauma were around 1.5 times more likely to not respond or remit after pharmacotherapy, psychotherapy, or combination treatment, than those without childhood trauma.

"This study is the largest of its kind to look at the effectiveness of depression treatments for adults with childhood trauma and is also the first to compare the effect of active treatment with control condition (waitlist, placebo, or care-as-usual) for this population. Around 46% of adults with depression have a history of childhood trauma, and for chronic depression sufferers the prevalence is even higher. It is therefore important to determine whether current treatments offered for major depressive disorder are effective for patients with childhood trauma," says Ph.D. Candidate and first author of the study, Erika Kuzminskaite.

The researchers used data from 29 clinical trials of pharmacotherapy and psychotherapy treatments for major depressive disorder in adults, covering a maximum of 6,830 patients. Of the participants, 4,268 or 62.5% reported a history of childhood trauma. Most of the clinical trials (15, 51.7%) were conducted in Europe, followed by North America (9, 31%). Depression severity measures were determined using the Beck Depression Inventory (BDI) or Hamilton Rating Scale for Depression (HRSD).

The three research questions tested were: whether childhood trauma patients were more severely depressed prior to treatment, whether there were more unfavorable outcomes following active treatments for patients with childhood trauma, and whether childhood trauma patients were less likely to benefit from active treatment than control condition.

In line with the results of previous studies, patients with childhood trauma showed greater symptom severity at the start of treatment than patients without childhood trauma, highlighting the importance of taking symptom severity into account when calculating treatment effects.

Although childhood trauma patients reported more depressive symptoms at both the start and end of the treatment, they experienced similar symptom improvement compared to patients without childhood trauma history. Treatment dropout rates were also similar for patients with and without childhood trauma. The measured treatment efficacy did not vary by childhood trauma type, depression diagnosis, assessment method of childhood trauma, study quality, year, treatment type or length.

"Finding that patients with depression and childhood trauma experience similar treatment outcome when compared to patients without trauma can give hope to people who have experienced childhood trauma. Nevertheless, residual symptoms following treatment in patients with childhood trauma warrant more clinical attention as additional interventions may still be needed. To provide further meaningful progress and improve outcomes for individuals with childhood trauma, future research is necessary to examine long-term treatment outcomes and mechanisms through which childhood trauma exerts its long-lasting effects," says Erika Kuzminskaite.

The authors acknowledge some limitations with this study, including a high variety of results among the studies included in the meta-analysis, and all cases of childhood trauma being reported retrospectively. The meta-analysis focused on symptom decline during acute treatment phase, but people with depression and childhood trauma often show post-treatment residual symptoms and are characterized by a high risk of relapse, thus they may benefit from treatment significantly less than patients without childhood trauma in the long run. The study design also did not account for differences between genders.

Writing in a linked Comment, Antoine Yrondi, University of Toulouse, France (who was not involved in the research) said, "This meta-analysis could allow to deliver a hopeful message to patients with childhood trauma that evidence-based psychotherapy and pharmacotherapy could improve depressive symptoms. However, physicians should keep in mind that childhood trauma could be associated with clinical features which may make it more difficult to reach complete symptomatic remission, and therefore, have an impact on the daily functioning."