Introduction:
A dysbalance of the immune system in psychotic disorders has been well investigated. However, despite a higher prevalence of cannabis (THC) consumption in patients with psychosis, few studies have investigated the impact of this use on inflammatory markers.
Methods:
One hundred and two inpatients were included in this retrospective study. Leukocytic formula, hsCRP, fibrinogen levels and urinary THC were measured, and comparisons were performed at baseline and after 4 weeks of cannabis cessation between cannabis users (THC+) and non-users (THC-).
Results:
After cannabis cessation, we found a greater increase of leucocyte level (p < 0.01), monocyte level (p = 0.05) and a statistical trend to a highest increase of lymphocyte level (p = 0.06) between baseline and 4 weeks in the THC+ group as compared to the THC- group. At 4 weeks, highest leucocyte (p = 0.03), lymphocyte (p = 0.04) and monocyte (p < 0.01) counts were found in the THC+ group whereas at baseline no difference was found. A positive correlation was found between monocyte count at 4 weeks and baseline PANSS negative subscore (p = 0.045) and between the variation of monocyte count between baseline and 4 weeks and the PANSS total score at 4 weeks (p = 0.05).
Conclusion:
THC cessation is associated with an increase in inflammatory markers, including white blood cell, lymphocyte, and monocyte levels, which correlates with symptomatology of patients with psychosis.