Study register · detailKohortenstudie (Cox-Proportional-Hazards, prospektiv innerhalb FEP-Kohorte) · Psychosis Risk · 2014
Daily use, especially of high-potency cannabis, drives the earlier onset of psychosis in cannabis users.
Di Forti et al.·Schizophrenia BulletinImpact 2.2
HarmGRADELow462 citations
Samplen = 410 Pat.
ControlNever-users
EndpointAge at onset of psychosis
Blindingn.a.
DesignKohortenstudie (Cox-Proportional-Hazards, prospektiv innerhalb FEP-Kohorte)
Cannabinoidvollspektrum
Routeinhalativ
”Key finding
Daily use of high-potency cannabis shifts psychosis onset forward by an average of 6 years.
Summary
n=410 first-episode psychosis patients, Cox proportional hazards model: Cannabis use → earlier first onset of psychosis HR=1,42 (95%-CI 1,16–1,74; p<0,001). Early onset ≤15 years HR=1,40 (95%-CI 1,06–1,84; p=0,050). Daily high-potency cannabis (skunk) → earliest first manifestation: mean age 25,2 years vs. 31,4 years in never-users (HR=1,99; 95%-CI 1,50–2,65; p<0,0001); first manifestation on average 6 years earlier than in non-users.
InterventionCannabis use (daily, high-potency [skunk-type], onset ≤15 years)
C
ControlNever-users (no history of cannabis use)
O
OutcomeDaily use of high-potency cannabis associated with earliest psychosis onset (HR=1,99; 95%-CI: 1,50–2,65; p<0,0001); onset on average 6 years earlier than in non-users
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 sizeHarm
Citations / year★★★★★
Authors
Di Forti M, Sallis H, Allegri F, Trotta A, Ferraro L, Stilo SA, Marconi A, La Cascia C, Reis Marques T, Pariante C, Dazzan P, Mondelli V, Paparelli A, Kolliakou A, Prata D, Gaughran F, David AS, Morgan C, Morgan C, Stahl D, Khondoker M, MacCabe JH, Murray RM.
Design: Kohortenstudie (Cox-Proportional-Hazards, prospektiv innerhalb FEP-Kohorte)
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Abstract
<h4>Unlabelled</h4>Cannabis use is associated with an earlier age of onset of psychosis (AOP). However, the reasons for this remain debated.<h4>Methods</h4>We applied a Cox proportional hazards model to 410 first-episode psychosis patients to investigate the association between gender, patterns of cannabis use, and AOP.<h4>Results</h4>Patients with a history of cannabis use presented with their first episode of psychosis at a younger age (mean years = 28.2, SD = 8.0; median years = 27.1) than those who never used cannabis (mean years = 31.4, SD = 9.9; median years = 30.0; hazard ratio [HR] = 1.42; 95% CI: 1.16-1.74; P < .001). This association remained significant after controlling for gender (HR = 1.39; 95% CI: 1.11-1.68; P < .001). Those who had started cannabis at age 15 or younger had an earlier onset of psychosis (mean years = 27.0, SD = 6.2; median years = 26.9) than those who had started after 15 years (mean years = 29.1, SD = 8.5; median years = 27.8; HR = 1.40; 95% CI: 1.06-1.84; P = .050). Importantly, subjects who had been using high-potency cannabis (skunk-type) every day had the earliest onset (mean years = 25.2, SD = 6.3; median years = 24.6) compared to never users among all the groups tested (HR = 1.99; 95% CI: 1.50- 2.65; P < .0001); these daily users of high-potency cannabis had an onset an average of 6 years earlier than that of non-cannabis users.<h4>Conclusions</h4>Daily use, especially of high-potency cannabis, drives the earlier onset of psychosis in cannabis users.