Table 2.
Characteristics of studies for cannabis use disorders.
| Study | Study design | Sample size | Types of sample | Demographics of sample | Country | Diagnosis of sample | Method of diagnosis | Attention bias method | Outcomes |
|---|---|---|---|---|---|---|---|---|---|
| CANNABIS USE DISORDERS | |||||||||
| Field et al. (26) | Case control | 17 regular cannabis users 16 non-users | Students and Staff at the University of Southampton | 5 males, 12 females in the group of cannabis users Mean age of 22.4 years Median length of time cannabis smoked 3 years 4 males, 12 females in control group. Mean age 20.9 years. | United Kingdom | Cannabis | No mention of any diagnostic tools | Visual Probe Task | High levels of craving associated with significant attention bias for cannabis-related words |
| Field et al. (27) | Cross-sectional study | 28 recreational cannabis users, including 15 in the “dependent” group and 13 in the “non-dependent” group | Students or staff at the University of Liverpool | 6 female, 22 male Mean age was 21.9 years | United Kingdom | Cannabis Dependence | Scores on the Cannabis Severity Dependence Scale | Drug Stroop task | Significant attention bias in the cannabis group No association between attention bias and frequency of cannabis use or subjective craving |
| Field et al. (28) | Case control | 23 regular cannabis users 23 non-user controls | Students and staff at the University of Liverpool | Cannabis users mean age was 23.04 Non-users mean age was 21.30 Gender ratio for Cannabis users: 14:9 (M:F) Gender ratio for non-users 8:15 (M:F) | United Kingdom | Cannabis abuse | Self-report usage of drugs | Visual Probe task with concurrent eye movement monitoring | Regular cannabis users had biases to maintain gaze on cannabis cues, and faster approach responses to cannabis cues |
| Cane et al. (29) | Cross-sectional study | 17 marijuana-smokers 15 non-marijuana smokers | Students from the University of Kent | Not provided | United Kingdom | Cannabis dependence | Screening questionnaire | Drug Stroop task | Mean reaction time was significant for the marijuana group (Mean time for marijuana words was 984ms, neutral words was 895ms). |
| Cousijin et al. (30) | Cross-sectional study | 32 heavy cannabis users and 39 non-using controls | Recruited through advertisements on the Internet and in Cannabis outlet (coffee-shops) | 34% females for heavy cannabis users, mean age 21.2 37% female for controls, mean age 22.0 | Netherlands | Cannabis dependence | Cannabis Use Disorder Identification Test and Structured Diagnostic Interview (MINI) | Approach and Avoidance Task | Heavy cannabis users had approach bias for cannabis as compared to controls. Approach bias was predictive of cannabis use at 6 months follow-up. |
| Cousijn et al. (31) | Cross-sectional Study | 42 heavy cannabis users with intentions to use 45 heavy cannabis users shortly after cannabis usage | Recruited in five different cannabis outlets | 82 males, 8 females Aged 18-59 | Netherlands | Cannabis dependence | Cannabis Use Disorder Identification Test-Revised | Approach and Avoidance Task | Heavy cannabis users with the intention to use did not show a cannabis approach bias, whereas intoxicated cannabis users did show an approach bias regardless of image category. Moreover, craving was negatively associated with the approach bias, and no relationships were observed between the cannabis approach bias, satiation, prior cannabis use, and response inhibition |
| Cousijin et al (32) | Cross-sectional study | 27 heavy cannabis users 26 controls | All recruited via Internet advertisement and Amsterdam coffee shops | 30% females in cannabis group, 38% females in control group Mean age 24.0 years in cannabis group Mean age 25.3 years in control group | Netherlands | Cannabis dependence | Cannabis Use Disorder Identification Test-Revised | Classical and Cannabis Stroop test | Cannabis smokers as compared to control group have stronger attentional bias for cannabis word Within the group of cannabis users, those who were clinically recognized as dependent showed a stronger attentional bias than the heavy, non-dependent users. Cannabis users who displayed reduced cognitive control (as measured with the classical Stroop task) showed increased session-induced craving. Cognitive control did not appear to modulate the relationship between attentional bias to cannabis words (cannabis Stroop task) and cannabis dependence. |
| Metrik et al. (33) | Cross-sectional | 93 participants | Recruited from community | 34.4% female | United States | Cannabis dependence | SCID-IV-NP for assessment of cannabis dependence | Marijuana Stroop Test | Presence of Attention bias to marijuana words (mean time was 752.89) vs. control (721.88) p < 0.001 |
| Vujanovic et al. (34) | Cross-sectional | 12 adults with cannabis use disorders 13 controls | Recruited via local advertisements | 8 female Mean age 31, range 22-45 | United States | Cannabis use disorder | Screening test and structured clinical interview for DSM-IV Axis I disorder | Pictorial stimuli attention bias task | Cannabis use disorders group showed greater attentional bias to cannabis cues at the 125-ms probe time Cannabis use disorders group also reported greater perceived stress and post-task stress scores |