Cannabis use and age at onset of symptoms in subjects at clinical high risk for psychosis.
Dragt et al.·Acta Psychiatrica Scandinavica
Clear benefitGRADELow100 citations
Samplen = 245 Pat.
Duration18-month follow-up
EndpointAge at symptom onset
Blindingn.a.
DesignProspektive multizentrische Kohortenstudie
”Key finding
Earlier cannabis use is significantly associated with earlier onset of high-risk and prodromal symptoms for psychosis.
Summary
Prospective multicenter study (n=245 high-risk individuals, 18 months follow-up): Younger age of onset of cannabis use or cannabis use disorder correlated significantly with younger symptom onset for 6 prodromal symptoms (0,33 < r_s < 0,83; p<0,004 to p<0,001). Cannabis onset preceded symptom onset in most participants. Result supports a causal role of early use in the development of psychosis in vulnerable individuals.
P
PopulationHelp-seeking individuals with clinical high risk of psychosis (CHR), n=245
I
InterventionCannabis use (onset and cannabis use disorder, assessed with CIDI)
O
OutcomeEarlier age of onset of cannabis use correlated significantly with earlier onset of six high-risk or prodromal symptoms (0,33 < rs < 0,83; 0,004 < p < 0,001); in most cases cannabis use preceded symptom onset
Confidence in the evidence
Very lowLowModerateHigh
Low
The second of four GRADE levels, the effect estimate is of limited reliability.
Quality profile
Sample size★★★★★
Blinding—
Effect sizeClear benefit
Citations / year★★★★★
Authors
Dragt S, Nieman DH, Schultze-Lutter F, van der Meer F, Becker H, de Haan L, Dingemans PM, Birchwood M, Patterson P, Salokangas RK, Heinimaa M, Heinz A, Juckel G, Graf von Reventlow H, French P, Stevens H, Ruhrmann S, Klosterkötter J, Linszen DH, EPOS group.
<h4>Objective</h4>Numerous studies have found a robust association between cannabis use and the onset of psychosis. Nevertheless, the relationship between cannabis use and the onset of early (or, in retrospect, prodromal) symptoms of psychosis remains unclear. The study focused on investigating the relationship between cannabis use and early and high-risk symptoms in subjects at clinical high risk for psychosis.<h4>Method</h4>Prospective multicenter, naturalistic field study with an 18-month follow-up period in 245 help-seeking individuals clinically at high risk. The Composite International Diagnostic Interview was used to assess their cannabis use. Age at onset of high risk or certain early symptoms was assessed retrospectively with the Interview for the Retrospective Assessment of the Onset of Schizophrenia.<h4>Results</h4>Younger age at onset of cannabis use or a cannabis use disorder was significantly related to younger age at onset of six symptoms (0.33 < r(s) < 0.83, 0.004 < P < 0.001). Onset of cannabis use preceded symptoms in most participants.<h4>Conclusion</h4>Our results provide support that cannabis use plays an important role in the development of psychosis in vulnerable individuals. Cannabis use in early adolescence should be discouraged.