Table 1.

Studies performed on humans.

Functions	Ref.	P. number	Testing methods	Treatment	Results	Type of users
Concentration; memory; language; visuoconstructional skills; conceptual thinking; calculation; orientation; executive functions; attention speed; motor speed; visual search speed; ordering skills; mental flexibility; persistence; response inhibition; susceptibility to interference; verbal attention; continuous and selective attention	(22)	145	Montreal Cognitive Assessment (MOCA) Test, Verbal Memory Processes Test (VMPT), Clock Drawing Test, Cube Drawing Test, Trial Making Test, Verbal Fluency Test, Digit Span Test, Continuous Performance Test (CPT), Stroop Test, Go/No-Go Test	–	More severe impairments in attention, memory, executive and visuospatial functions in the SC group than in the cannabis and the healthy control groups	Chronic SCs users, chronic cannabis users, non-users
Executive functions; emotional processing; depression and anxiety traits	(28)	122	Beck depression inventory (BDI), Spielberg state-trait anxiety inventory (STAI), Stroop word-color task, N-back task, free-recall memory task	–	In the SC group impairments in working/long-term memory, response inhibition. Higher ratings of depression and anxiety	Chronic SCs users, chronic cannabis users, non-users
Working memory; response inhibition; depression and anxiety traits	(27)	33	Working memory N-back task, response-inhibition Go-No-Go task, Beck depression inventory (BDI), State-trait anxiety inventory (STAI)	–	In SC group higher ratings on the BDI, STAI compared with control participants. SC impaired performance on the N-back task, but not on the Go-No-Go task	Chronic SCs users, non-users
Cognitive performance; attention; executive functions; planning; memory; subjective experience	(25)	6	Digit symbol substitution task (DSST), Critical tracking test (CTT), Divided attention task (DAT), Stop signal task (SST), Tower of London (TOL), Spatial memory task (SMT), Subjective high, Profile of moods states (POMS), Bowdle visual analog scales, marijuana craving questionnaire (MCQ), Sensitivity to Cannabis Reinforcement Questionnaire (SCRQ), Clinician-administered dissociative States Scale (CADSS)	Inhalation JWH-018 (2–3 mg) or placebo	JWH-018 impaired motor performance (CTT), divided attention (DAT) and response inhibition (SST), particularly after the 2 mg dose. Executive functioning (TOL), spatial memory (SMT), speed and information processing (DSST) were not affected by JWH-018	Occasional cannabis users
Cognitive performance; attention; executive functions; memory; subjective experience	(26)	17	Digit symbol substitution DSST, critical tracking task CTT, divided attention task DAT, stop signal task SST, Tower of London TOL, spatial memory task [SMT], Profile of Mood States [POMS], Bowdle visual analog scales, Marijuana Craving Questionnaire [MCQ], Sensitivity to Cannabis Reinforcement Questionnaire [SCRQ], Clinician-Administered Dissociative States Scale [CADSS]	Inhalation of JWH-018 (2–6.2 mg, average 3.95 mg) or placebo	Lower CTT, SST, SMT scores in CS group. No significant effects in DAT, TOL, and DSST. Large variability in the subjective response to the drug	Occasional cannabis users
Visuospatial functions; executive functions; attention; working memory; speaking; abstract thinking; hand preference; motor speed; information processing speed	(23)	63	Montreal Cognitive Assessment (MOCA) test, Edinburgh Handedness Inventory (EHI), Finger-Tapping Test (FTT), Adult Memory and Information Processing Battery-B form (AMIPB-B)	–	SC group scored worse in AMIPB-B, MOCA, and FTT	Chronic SCs users, non-users
Executive functions; emotional processing; depression and anxiety traits	(24)	94	N-back task, Go/No-Go task, Wisconsin Sorting Card-like Task (WSCT), emotional face recognition task, questionnaires of depression, anxiety and schizotypal traits	–	SC group scored worse on the N-back working-memory task and WSCT cognitive flexibility task; showed greater schizotypal traits and symptoms and higher scores on depression and state-trait anxiety measures	Chronic SCs users, chronic cannabis users, non-users
Motor coordination; attention; memory; speed-accuracy efficiency; response speed; motor impulsivity; reflection impulsivity; planning	(21)	24	Critical Tracking Test (CTT), VAS, Divided Attention Task (DAT), Spatial Memory Task (SMT), Stop Signal Task (SST), Matching Familiar Figures Test (MFFT), Digit Symbol Substitution Task (DSST), Tower of London (TOL), subjective high	Inhalation of JWH-018 (75 μg/kg plus booster dose of 50 μg/kg, average 5.52 mg) or placebo	Maximum subjective high 30 min after administration, maximum blood concentration after 5 min (8 ng/mL). Impaired motor coordination, attention, memory. Lower speed-accuracy efficiency, slowed response speed in a 4-h window after administration, most strongly within the first 2.5 h	Occasional cannabis users

Ref., reference number; P. number, participants' number.