A systematic review of the association between biological markers and environmental stress risk factors for adolescent depression

• Published in: Journal of psychiatric research 2021-06, Vol.138, p.163-175
• Main Authors: Zajkowska, Zuzanna, Walsh, Annabel, Zonca, Valentina, Gullett, Nancy, Pedersen, Gloria A., Kieling, Christian, Swartz, Johnna R., Karmacharya, Rakesh, Fisher, Helen L., Kohrt, Brandon A., Mondelli, Valeria
• Format: Article
• Language: English
• Subjects: Adolescence; Adolescent; Biomarkers; Brain; Child maltreatment; Cortisol; Cross-Sectional Studies; Depression; Depressive Disorder, Major - epidemiology; Early life adversity; Humans; Inflammation; Major depressive disorder; MDD; MRI; Prospective Studies; Risk Factors; Young Adult; Young people; Youth
• ISSN: 0022-3956; 1879-1379
• DOI: 10.1016/j.jpsychires.2021.04.003

Although the aetiology and pathophysiology of depression are multifactorial, to date most studies have examined either biological or environmental mechanisms without looking at the integration of both; with most studies conducted in high-income countries (HICs). Therefore, we conducted a systematic review of worldwide studies investigating the relationship between biological and environmental stress risk factors for major depressive disorder (MDD) in adolescence. We searched MEDLINE (via Ovid), PsycINFO, Cochrane Database of Systematic Reviews, Web of Science (Core Collection), Lilacs, African Journals Online and Global Health for prospective and cross-sectional studies that examined the association between biological markers and environmental stress risk factors in MDD during adolescence. Of 11,089 articles identified, 21 were included, with only two from middle-income countries. Increased inflammation, telomere length and brain abnormalities, including blunted reward-related activity, white matter disruptions, and altered volume of limbic brain regions, were associated with increased risk for MDD mainly in the context of early life adversity. There is little evidence suggesting that the neurobiological changes investigated were associated with MDD in the context of recent life stress. The developmental trajectory of depression appears to start with early life adversities and occurs in the context of immune and brain abnormalities. Understanding these biopsychosocial processes will help to improve our ability to detect individuals at risk of developing depression in adolescence. However, generalizability is limited by few studies examining both biological and environmental stress risk factors and a lack of studies on adolescents and young adults in low-and-middle-income countries (LMICs). •Inflammation and depression in youth only present in the context of child adversity.•Brain alterations mediate the link between child adversity and depression in youth.•Limited studies on environmental and biological risk factors in youth depression.•Immune and brain markers – potential for prevention and treatment of depression.