Comorbid diagnoses for youth at clinical high risk of psychosis.
Level 3 - non-randomized controlled study
Prospective multi-center longitudinal cohort study with a healthy control group.
PubMed 28372906 · doi:10.1016/j.schres.2017.03.043
What was done
Researchers in the North American Prodrome Longitudinal Study (NAPLS 2) evaluated baseline and longitudinal DSM-IV psychiatric comorbidities in 744 youth at clinical high risk (CHR) for psychosis and 276 healthy controls, assessing whether comorbid conditions influenced conversion to full psychosis.
What was found
Comorbid psychiatric conditions were present in 79% of the CHR cohort (only 21% had no comorbid diagnosis), with many participants meeting criteria for 2 to 3 comorbid disorders. The most prevalent baseline conditions were anxiety and depressive disorders, which improved over time. Baseline cannabis misuse was the only comorbid diagnosis that statistically differentiated individuals who converted to psychosis from non-converters; other comorbid conditions were independent of psychotic conversion.
Why it matters
While affective and anxiety symptoms drive help-seeking and constitute substantial baseline morbidity in at-risk youth, they do not inherently elevate the risk of transition to psychosis, whereas substance misuse (specifically cannabis) serves as a distinct prognostic marker.
Limits
The abstract does not provide exact odds ratios, hazard ratios, transition rates, or p-values. The cohort represents help-seeking individuals enrolled in specialized research clinics, introducing potential selection bias regarding comorbidity rates.
Cited by
- supports Schizophrenia is typically preceded by mood disorders like depression and anxiety.