Being mistreated as a child may make a person more vulnerable to depression in later life, according to new research.
Childhood trauma can affect the structure of the brain and predispose adults to recurring major depressive disorder, the study published in The Lancet Psychiatry journal suggests.
Previous studies have suggested an association between mistreatment and altered brain structure, while others have identified an association between mistreatment and major depressive disorder.
This is the first study that directly establishes a link between mistreatment experiences, brain structural alterations and the clinical course of depression.
It is also the first to shed light on the physical changes to the brain that might be involved. So-called “limbic scars” have been identified in patients before, but they have taken a different form to the alterations seen in the new research.
All 110 participants in the German study had been admitted to hospital following a diagnosis of major depression and were receiving inpatient treatment. They were recruited to the study between 2010 and 2016.
The severity of their symptoms was assessed using questionnaires and interviews and all participants underwent an MRI scan. The presence and level of childhood maltreatment was also assessed via a questionnaire.
The MRI images suggest that both childhood maltreatment and recurring depression are associated with similar reductions in the surface area of the insular cortex, a part of the brain believed to help regulate emotion and self-awareness. The observed reduction could make a future relapse more likely.
Childhood maltreatment is one of the strongest risk factors for major depression.
It is believed depressed patients who were mistreated as children are clinically distinct from patients who were not mistreated but have the same diagnosis. They may also be less responsive to conventional treatments.
A shortcoming of the research is that experiences of childhood mistreatment and depression were assessed retrospectively and could be subject to recall bias.
