Diagnosing depression remains challenging in some people, despite well-known risk factors and symptoms of the condition. Now, new brain scans may lead to a screening tool that could be used to identify people who are vulnerable to depression later in life, possibly allowing early treatment and, possibly, prevention.

A new brain imaging study, published in Biological Psychology, reports that there are distinct brain differences in children known to be at risk of depression compared to children not an increased risk.

Researchers from Harvard Medical School and the Massachusetts Institute of Technology scanned the brains of 27 children aged 8 to 14 years who were considered high-risk for depression because of their family histories. They also scanned the brains of 16 children with no known family history of depression. The team used functional magnetic resonance imaging (fMRI) to measure the communication and connections between regions of the brain and identified patterns in children at risk for depression. Specifically, there was a strong connection between the subgenual anterior cingulate cortex and the default mode network (the regions that are active when the mind is unfocused). This same connection has been observed in adults with depression.

The researchers also found active connections between the amygdala (which is important in processing emotions) and the inferior frontal gyrus (which is involved in processing language). They identified lower than normal connections in the frontal and parietal cortex (which are important for thinking and decision-making).

Several of the areas identified in the current study have been related to depression in previous studies, though it was unclear if the differences in activity levels and connections caused depression or if the differences were the result of it. The new findings suggest that the changes in brain activity come before the onset of depression, which may allow for the screening of people without depression to identify who is likely to develop depression later in life and who is not. Ultimately, such screening and identification could lead to early treatment and intervention. This information may also help to understand why some people who are at risk for depression avoid the disorder altogether.

Early intervention is important for depression because, once a person suffers with its first symptoms, he or she is more likely to experience them again. If someone can avoid the onset of symptoms, his or her life – and mental health – may take an entirely different path. Effective treatment for depression, which often includes medication and psychotherapy, is important for avoiding serious complications of depression such as poor school and work performance, decreased social functioning, recurrent episodes of depression, and suicide.

While the exact mechanisms of depression are still unclear, this study highlights the fact that functional and structural features of the brain do play a part in its development. Social, educational, and family context and experience also certainly play a role in mental health and depression. The more aware we are of risk factors for and early signs of depression, the more hope we can offer to those likely to face the illness.

References

Chai XJ, Hirshfeld-Becker D, Biederman J, Uchida M, Doehrmann O, Leonard JA, Salvatore J, Kenworthy T, Brown A, Kagan E, de Los Angeles C, Whitfield-Gabrieli S, & Gabrieli JD (2015). Functional and structural brain correlates of risk for major depression in children with familial depression. NeuroImage. Clinical, 8, 398-407 PMID: 26106565

Lewis CP, Nakonezny PA, Ameis SH, Vande Voort JL, Husain MM, Emslie GJ, Daskalakis ZJ, & Croarkin PE (2016). Cortical inhibitory and excitatory correlates of depression severity in children and adolescents. Journal of affective disorders, 190, 566-75 PMID: 26580570

Luby JL, Belden AC, Jackson JJ, Lessov-Schlaggar CN, Harms MP, Tillman R, Botteron K, Whalen D, & Barch DM (2016). Early Childhood Depression and Alterations in the Trajectory of Gray Matter Maturation in Middle Childhood and Early Adolescence. JAMA psychiatry, 73 (1), 31-8 PMID: 26676835

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