Childhood trauma can affect brain structure, predisposing adults to recurrent major depressive disorder

Early trauma can affect brain structure to make clinical depression more likely and more severe, according to a two-year observational study of 110 patients published in Lancet Psychiatry newspaper.

Previous studies have suggested an badociation between maltreatment and an impaired brain structure, while others have identified an badociation between maltreatment and major depressive disorder. This is the first study that directly links maltreatment experiences, structural alterations of the brain, and the clinical course of depression. It is also the first to illuminate the physical changes that may be involved in the brain. "Limbic scars" have already been identified in patients, but they have taken a different form from the alterations observed in the new research.

All participants in this study, aged 18 to 60 years, were hospitalized following a diagnosis of major depression and underwent hospital treatment. They were recruited into the study between 2010 and 2016. The severity of their symptoms was badessed using questionnaires and interviews at two different times (at the time of initial recruitment and at the time of A two-year follow-up visit), and all participants were subjected to a structural evaluation. MRI to recruitment. The presence and level of child abuse was also badessed through a questionnaire.

The results of the MRI images suggest that child abuse and recurrent depression are badociated with similar reductions in the area of ​​the insular cortex, a part of the brain that is thought to help regulate emotions and self-awareness. The results suggest that the observed reduction may make a future relapse more likely. Child abuse is one of the most important risk factors for major depression.

"Our findings add weight to the notion that patients with clinical depression who have been abused in childhood are clinically distinct from non-abused patients with the same diagnosis," says Dr. Nils Opel of the University. from Münster, Germany, who led the research. . "Given the impact of the insular cortex on brain function such as emotional awareness, it is possible that the observed changes make patients less sensitive to conventional treatments, so future research in psychiatry should explore how our findings could be translated into attention, special care and treatment, this could improve outcomes for patients. "

Patients were divided into two groups: those who did not relapse during the two-year period (35 persons – 17 men and 18 women) and those who experienced at least one additional depressive episode (75 persons – 35 men and 40 women). Of the 75 patients in the relapse sample, 48 had an additional episode, seven had reported two episodes and six had three episodes, while 14 had a remission period of less than two months and could therefore be considered as suffering from chronic depression. Child maltreatment was significantly badociated with the relapse of depression.

In previous research, longitudinal studies only explored clinical status at follow-up and did not consider clinical symptoms between badessments. For the new study, researchers badessed information on depressive symptoms over a full two-year period. Two years after recruitment, all participants were invited to participate in a follow-up badessment in which symptoms of the entire two-year period were badessed retrospectively.

The authors note that one of the limitations of this work is that child abuse experiences and depressive symptoms have been evaluated retrospectively and may therefore be subject to recall bias.

Lianne Schmaal, from the University of Melbourne, Australia, explains in a commented commentary: "It remains to be seen whether, in the sample studied in the study by Opel and colleagues, the observed reduction in island surface reflects stable state, trait or normalizes over time with remission of depression, because in their previous study, researchers only reported how longitudinal changes in cortical thickness – but no surface area – fluctuated with relapse of depression. "

She adds: "[This] The study is an important contribution to our knowledge of the mechanisms that confer a risk of relapse of depression. A better understanding of these mechanisms is crucial for developing or improving risk-appropriate interventions for people who may have a worse long-term clinical outcome. "

Provided by
Lancet