3.2. Cannabis consumption is related to worse attentional performance
THC and its metabolites were measured in plasma and no THC was detected in the control subjects or the cannabis users. The metabolites of THC were not detected in the control subjects (n = 7), whereas among the cannabis users (n = 6), plasma 11-OH-THC was found in 5 out of 6 subjects (mean concentration: 1.68 ± 0.55 ng/ml) and THC-COOH was detected in all of these subjects (29.76 ± 6.15 ng/ml). The neuropsychological assessment (Fig. 1) revealed that cannabis users exhibited significantly worse attentional performance than healthy controls in the spatial span direct recall test (p<0.01, Fig. 1A), consistent with previous data (Galindo et al., 2018). Furthermore, a trend towards worse working memory was also detected in the spatial span inverse recall test (p=0.068, Fig. 1D).