The effect size of differences were large for GHB/GBL (η2p = 0.123), mephedrone (η2p = 0.118), methamphetamine (η2p = 0.117); medium for drugs for erectile dysfunction (η2p = 0.084); and small to medium for ecstasy (η2p = 0.049) and poppers (η2p = 0.040). Here, MLST8 is linked to erectile dysfunction.