Persistent cannabis use worsens symptomatology and functional level in psychosis; cessation of use normalises outcome to the level of never-users.
Summary
10-year cohort study (n=209 first-episode psychosis patients, PAFIP cohort): Persistent cannabis users showed significantly more severe symptoms (BPRS: χ²=15.583, p<0.001; SAPS: χ²=12.386, p=0.002) and worse functionality (DAS: χ²=6.067, p=0.048; GAF: χ²=6.635, p=0.033) compared to ex-users and never-users. Ex-users showed outcomes similar to never-users.
P
PopulationPatients with first-episode psychosis (FEP), n=209, PAFIP cohort
I
InterventionPersistent cannabis use vs. cessation of use (ex-users)
C
ControlNever-users
O
OutcomePersistent cannabis users showed more severe symptoms after 10 years (BPRS: p≤0.001; SAPS: p=0.002) and worse functioning (DAS: p=0.048; GAF: p=0.033); ex-users did not differ from never-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
Setién-Suero E, Neergaard K, Ortiz-García de la Foz V, Suárez-Pinilla P, Martínez-García O, Crespo-Facorro B, Ayesa-Arriola R.
<h4>Objective</h4>To examine the long-term (up to 10 years) patterns related to cannabis use in a sample of patients with first episode of psychosis (FEP) and the effect that consumption might have on clinical, functioning, and neurocognition at long-term.<h4>Methods</h4>Cannabis use was described in 209 FEP patients. Patients were divided into three groups according to cannabis use: persistent users, ex-users, and never-users. Groups were longitudinally (baseline and 10-year follow-up) compared on clinical, functional, and cognitive variables.<h4>Results</h4>Clinical differences at 10-year follow-up were observed between persistent cannabis users and the other two groups (ex-users and never-users), showing persistent users more severe symptoms (BPRS: x<sup>2</sup> = 15.583, P ≤ 0.001;
Saps: x<sup>2</sup> = 12.386, P = 0.002) and poorer functionality (DAS: x<sup>2</sup> = 6.067, P = 0.048;
Gaf: x<sup>2</sup> = 6.635, P = 0.033). Patients who stopped cannabis use prior to the reassessment showed a similar pattern to those who had never consumed.<h4>Conclusion</h4>The use of cannabis could negatively affect the evolution of the psychotic disorder. Perhaps the negative effects caused by cannabis use could be reversed with the cessation of consumption. It is necessary to make an effort in the intervention toward an early withdrawal from the use of cannabis, since this could play an important role in the prognosis of the disease.