Association between chronic psychoactive substances use and systemic inflammation : a systematic review and meta-analysis

This systematic review and meta-analysis assess the change in inflammation biomarkers level among chronic psychoactive substance users. To meet the required inclusion criteria, all studies had to describe human participants with an age ≥18y., experiencing chronic psychostimulant (nicotine, amphetamine, cocaine), sedative (benzodiazepine, opioids) and/or cannabinoid use. The comparison group was defined as healthy participants. Studies where included if they reported at least one of the pro/inflammatory biomarkers. Study bias was examined by Funnel plots and heterogeneity by computing the I2 statistics. Only 21 eligible studies were selected based on 26216 study participants. A small and significant effect size of 0.18mg/L (95% CI:0.10-0.27) was detected in favor of chronic smokers (z=4.33;P