Demographic and clinical characteristics of the data set included in the meta-analysis
| Data set | Sample, n | Mean age (± SD), yr | Age range, yr | Females, n | Addiction | Mean duration of use (± SD), yr | Mean age of onset (± SD), yr | Medication | ||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Substance dependence | Healthy controls | Substance dependence | Healthy controls | Substance dependence | Healthy controls | Substance dependence | Healthy controls | |||||
| Substance dependence subgroup | ||||||||||||
| Beck et al.44 | 19 | 19 | 41.84 ± 6.79 | 41.68 ± 8.97 | NA | NA | 0 | 0 | Alcohol | 11.50 ± 5 | NA | No |
| Becker et al.20 | 20 | 20 | 44.20 ± 10.30 | 44.90 ± 9.60 | NA | NA | 7 | 9 | Alcohol | NA | NA | NA |
| Bedi et al.45 | 22 | 19 | 52.90 ± 2.50 | 52.70 ± 2.60 | NA | NA | 4 | 4 | Cocaine | 21.70 ± 4.40 | NA | No |
| Bischoff-Grethe et al.46 | 17 | 23 | 38 ± 8.70 | 38 ± 11.90 | NA | NA | 0 | 3 | Methamphetamine | 5.24 ± 4.25 | 25.40 ± 8.60 | NA |
| Cousijn et al.47 | 32 | 41 | 21.40 ± 2.30 | 22.20 ± 2.40 | NA | NA | 11 | 15 | Cannabis | 2.50 ± 1.90 | NA | No |
| de Ruiter et al.23 | 18 | 19 | 34.80 ± 9.80 | 34.10 ± 9.30 | NA | NA | 0 | 0 | Cigarette | NA | NA | No |
| Filbey et al.48 | 59 | 27 | 23.49 ± 6.37 | 30.32 ± 10.09 | NA | NA | 13 | 22 | Marijuana | 8.56 ± 6.34 | 15.04 ± 2.63 | NA |
| Forbes et al.49 | 24 | 24 | 27.20 ± 4.90 | 27.20 ± 3.70 | NA | NA | 9 | 10 | Alcohol | 11.61 ± 5.53 | NA | No |
| Goldstein et al.50 | 16 | 13 | 42.80 ± 4.60 | 37.60 ± 6.80 | NA | NA | 4 | 4 | Cocaine | 17.60 ± 6.65 | 24.80 ± 8.04 | NA |
| Jia et al.51 | 20 | 20 | 38.60 ± 9.29 | 35.25 ± 10.19 | NA | NA | 8 | 8 | Cocaine | 11.05 ± 7.86 | NA | No |
| Luo et al.52 | 35 | 36 | 34.10 ± 7.90 | 31.30 ± 7.10 | NA | NA | 15 | 13 | Cigarette | > 2 | NA | NA |
| Martin et al.19 | 16 | 17 | 31.40 ± 9.82 | 33.73 ± 10.29 | NA | NA | NA | NA | Cigarette | > 0.5 | NA | No |
| Nestor et al.53 | 14 | 14 | 22.10 ± 4.50 | 23.10 ± 4.50 | NA | NA | 2 | 3 | Cannabis | 6.10 ± 1.10 | 16.10 ± 0.40 | NA |
| Romanczuk-Seiferth et al.24 | 15 | 17 | 45.40 ± 10.15 | 37.41 ± 11.76 | NA | NA | 0 | 0 | Alcohol | NA | NA | NA |
| Rose et al.54 | 28 | 28 | 32.68 ± 10.02 | 30.11 ± 7.83 | NA | NA | 15 | 12 | Cigarette | 16.48 | 15.46 | NA |
| Tobler et al.55 | 17 | 17 | 33 ± 8.60 | 34.50 ± 8.80 | NA | NA | 4 | 5 | Cocaine | 8.40 ± 5.30 | NA | NA |
| Van Hell et al.56 | 14 | 13 | 24 ± 4.40 | 24 ± 2.70 | NA | NA | 1 | 2 | Cannabis | NA | NA | No |
| Wrase et al.57 | 16 | 16 | 42.38 ± 7.52 | 39.94 ± 8.59 | 25–57 | 24–59 | 0 | 0 | Alcohol | 12.69 ± 7.09 | NA | No |
| Yi et al.58 | 16 | 17 | 32.19 ± 8.17 | 26.82± 5.29 | 21–50 | 21–50 | 0 | 0 | Opiates | NA | NA | NA |
| Yip et al.21 | 20 | 20 | 26.65 ± 2.19 | 29.20 ± 2.25 | NA | NA | 0 | 0 | Cannabis | NA | NA | NA |
| Yip et al.18 | 24 | 21 | 40.75 ± 10.18 | 34.57 ± 11.99 | NA | NA | 16 | 12 | Cocaine | 11.71 ± 8.08 | NA | Methadone |
| Gambling addiction subgroup | ||||||||||||
| Balodis et al.22 | 14 | 14 | 35.80 ± 11.70 | 37.10 ± 11.30 | NA | NA | 4 | 4 | Gambling | NA | NA | NA |
| Choi et al.59 | 15 | 15 | 27.90 ± 6.90 | 26.60 ± 4.30 | NA | NA | 0 | 0 | Gambling | 2.20 ± 1.29 | 25.67 ± 3.92 | No |
| de Ruiter et al.23 | 19 | 19 | 34.30 ± 9.40 | 34.10 ± 9.30 | NA | NA | 0 | 0 | Gambling | NA | NA | No |
| Romanczuk-Seiferth et al.24 | 18 | 17 | 33.56 ± 9.54 | 37.41 ± 11.76 | NA | NA | 0 | 0 | Gambling | NA | NA | NA |
| Sescousse et al.43 | 18 | 20 | 34.10 ± 11.60 | 31 ± 7.30 | NA | NA | 0 | 0 | Gambling | NA | NA | No |
NA = not available; SD = standard deviation.