Participant demographic and clinical characteristics*
| Characteristic | Healthy controls n = 43 | Ketamine users n = 20 | p value† |
|---|---|---|---|
| Age | 28 (24.5–34.5) | 27.5 (25–28.75) | 0.26 |
| Sex, male/female | 35/8 | 16/4 | > 0.99 |
| Education, yr | 12 (9.5–15) | 12 (10.5–14) | 0.32 |
| Body mass index, kg/m2 | 22.95 ± 3.37 | 22.61 ± 2.98 | 0.77 |
| Cigarettes smoked per day | 0 (0–15.5) | 20 (10–20) | 0.001 |
| State anxiety total score | 33.69 ± 9.37 | 35.26 ± 10.38 | 0.64 |
| Trait anxiety total score | 37.81 ± 8.12 | 41.67 ± 10.85 | 0.14 |
| Beck Depression Inventory II score | 3 (0–5) | 9 (5–15.25) | < 0.001 |
| Ketamine use | |||
| Age at onset, yr | – | 21 (16–25) | – |
| Duration of use, mo | – | 70.85 ± 35.42 | – |
| Amount used per day, g | – | 0.5 (0.3–1) | – |
| Lifetime amount used, g | – | 936.25 (199.5–1785) | – |
| Method of use | – | Snorting (100%) | – |
| Other drug use | |||
| Alcohol | 15 (34.9) | 11 (55.0) | 0.25 |
| Ecstasy | – | 6 (30.0) | – |
| Marijuana | – | 5 (25.0) | – |
| Methamphetamine | – | 7 (35.0) | – |
| “Ma Gu” (amphetamine and caffeine) | – | 8 (40.0) | – |
| Positive and Negative Syndrome Scale | |||
| Total score | – | 65 (60–99) | – |
| Positive scale score | – | 9 (8–18) | – |
| Negative scale score | – | 18 (13–23) | – |
| General psychopathology scale score | – | 37 (34–53) | – |