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FRIDAY, May 24, 2024 (HealthDay News) -- Mental disorders may be transmitted within an adolescent peer network, according to a study published online May 22 in JAMA Psychiatry.
Jussi Alho, Ph.D., from the University of Helsinki, and colleagues examined whether having classmates with a mental disorder diagnosis in ninth grade of comprehensive school is associated with a later risk for diagnosis with a mental disorder using data from a population-based registry study of all Finnish citizens born between Jan. 1, 1985, and Dec. 31, 1997.
The researchers found that 47,433 of the 713,809 cohort members had a mental disorder diagnosis by ninth grade. Of the remaining cohort members, 25.1 percent received a mental disorder diagnosis during 7.3 million person-years of follow-up. There was a dose-response association, with no significant increase in later risk with one diagnosed classmate but an increase with more than one diagnosed classmate (hazard ratio, 1.05). The risk was highest during the first year of follow-up (hazard ratios, 1.09 and 1.18 for one and more than one diagnosed classmate, respectively), but risk was not proportional over time. The greatest risk was seen for mood, anxiety, and eating disorders. After adjustment for an array of confounders, increased risk persisted.
"These findings suggest that mental disorders may be transmitted within adolescent peer networks," the authors write. "Consequently, prevention and intervention measures that consider potential peer influences on early-life mental health could substantially reduce the disease burden of mental disorders in society."