THE PRIVATE DIAGNOSIS OF A SOCIAL PROCESS
- il y a 2 jours
- 2 min de lecture
July 2026
If mental-health trajectories are partly produced within peer environments, why does psychiatry continue to record the outcome as an individual diagnosis? A Finnish cohort followed 604,819 people from age 17. Classmates’ psychiatric diagnoses were associated with later diagnoses, as was classmates’ family-based genetic risk—estimated from relatives’ records, not DNA. The associations remained after adjustment for the individual’s own familial risk and parental socioeconomic position and were strongest in upper-secondary-school networks (Alho et al. 2026).
The study does not show that disorders are simply contagious. It cannot determine how much arises from peer influence, selection into networks, shared conditions, similar routes into care, or unmeasured confounding. Its importance lies precisely in this unresolved mixture. Something occurs between people, yet the register sees it only after it has crossed the threshold of a person. The relation is treated as an exposure; the individual becomes the case.
This is psychiatry’s concealed category error. Its causal models increasingly admit schools, friendships, inequality, platforms, and social norms, but its clinical machinery still extracts one body from those relations, gives it a code, and returns the environment to statistical background. The diagnosis may be valid; the implied ownership of the disorder is not. A socially organized trajectory is administratively converted into private pathology—and the person is then asked to adapt to the conditions that helped produce it.
The forecast is a multiplication of psychiatric clusters misread as a multiplication of isolated illnesses. Psychiatry will screen earlier, diagnose faster, and treat each member separately while remaining uncertain whether it is measuring shared pathology, shared adversity, or shared routes of recognition. Unless peer networks become units of observation and intervention—not excuses for blaming groups—the system will perfect an epidemiology of outcomes while neglecting their production. It will count what appears inside individuals and remain clinically blind to what happened between them.
Liviu Poenaru
References
Alho, Jussi, Mai Gutvilig, Ripsa Niemi, Kimmo Suokas, Kaisla Komulainen, Petri Böckerman, Marko Elovainio, Roger T. Webb, and Christian Hakulinen. 2026. “Adolescent Peers’ Diagnoses and Genetic Predispositions and Subsequent Risk of Mental Disorders.” JAMA Psychiatry, July 1.
