Abuse during childhood can cause structural changes in the brain that increase a person's risk of severe and recurrent depression, a new study reveals.
The findings "add further weight to the notion that patients with clinical depression who were mistreated as children are clinically distinct" from people who didn't suffer such trauma in early life, said study leader Nils Opel. He's a psychiatric researcher at the University of Münster in Germany.
At least one relapse
The research included 110 people, aged 18 to 60, who were hospitalised with major depression. The severity of their depression was assessed while in the hospital and again two years later.
Patients also completed a questionnaire that asked about early life trauma, and underwent an MRI scan to assess their brain structure.
Seventy-five patients had at least one relapse of depression within two years of their hospitalisation, Opel's group reported in The Lancet Psychiatry. Of those, 48 had one relapse; seven had two; six had three; and 14 had so many they were considered chronically depressed.
Mistreatment in childhood was significantly associated with the tendency of depression to relapse, the researchers said.
Also, MRI scans suggested that both childhood abuse and recurring depression are associated with similar reductions in the surface of a brain area – the insular cortex – that helps regulate emotion and self-awareness, the study authors said.
Less responsive to treatment
This brain change could raise the risk of recurring depression, the researchers noted. And they added that childhood abuse (which can include emotional, sexual or physical mistreatment or neglect) is already one of the strongest known risk factors for major depression.
"Given the impact of the insular cortex on brain functions such as emotional awareness, it's possible that the changes we saw make patients less responsive to conventional treatments," Opel said in a journal news release.
Dr Robert Glatter is an emergency physician at Lenox Hill Hospital in New York City who often helps treat child abuse cases and people suffering from depression. He said that the new study "provides ongoing evidence of the plasticity of the brain during childhood, and how emotional abuse leads to structural and functional changes, which have lifelong and life-altering consequences".
And according to study author Opel, knowledge gained in this study might someday "be translated into special attention, care and treatment that could improve patient outcomes".
Prior studies have suggested a link between abuse and changes in brain structure, and others have found an association between abuse and major depression.
Changes may be permanent
But the German team said theirs is the first study to directly connect child abuse, changes in brain structure and the clinical course of depression. It is also the first to identify brain changes that may play a role.
One expert who reviewed the new findings did offer up a caveat, however.
Rosemarie Basile directs psychology services at Staten Island University Hospital in New York City. She called the findings "promising", but she noted that the study didn't account for any trauma people experienced in adult life, as well, so that could skew the results.
Lianne Schmaal, a senior research fellow at the University of Melbourne in Australia, wrote an editorial that accompanied the study. She said one important question that needs to be answered is whether the structural brain changes are permanent, or whether they normalise over time with remission of depression.
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