Table 1.
Demographic and clinical characteristics of study participants
| Measure | Healthy volunteers (n = 18) | People at clinical high risk for psychosis (n = 35) | Statistical test | p value |
|---|---|---|---|---|
| Age, yr, mean ± SD | 21.28 ± 1.99 | 20.57 ± 1.63 | F = 1.91 | p = 0.17 |
| Sex, male: female | 6:12 | 19:16 | χ2 = 2.09 | p = 0.15 |
| Current drug use, n* | ||||
| Nicotine | 0 | 8 | — | — |
| Cannabis | 0 | 4 | — | — |
| Lifetime history of recreational drug use (use > 10 times), n | ||||
| Cannabis | 0 | 17 | — | — |
| MDMA | 0 | 1 | — | — |
| Cocaine | 0 | 1 | — | — |
| LSD | 0 | 1 | — | — |
| Barbiturate | 0 | 1 | — | — |
| Antipsychotic use, n† | 0 | 5 | — | — |
| SOPS, mean ± SD | ||||
| Total | — | 36.03 ± 11.81 | — | — |
| Positive | — | 11.20 ± 3.76 | — | — |
| Negative | — | 11.37 ± 5.94 | — | — |
| Disorganization | — | 3.74 ± 2.65 | — | — |
| General | — | 8.86 ± 4.31 | — | — |
| AES, mean ± SD‡ | — | 39.06 ± 9.19 | — | — |
| CDSS, mean ± SD | — | 5.51 ± 4.03 | — | — |
| RBANS, total, mean ± SD | — | 90.94 ± 13.95 | — | — |
AES = Apathy Evaluation Scale; CDSS = Calgary Depression Scale for Schizophrenia; CHR = clinical high risk for psychosis; LSD = lysergic acid diethylamide; MDMA = 3,4-methylenedioxymethamphetamine (ecstasy); SOPS = Scale of Psychosis-Risk Symptoms; RBANS = Repeatable Battery for the Assessment of Neuropsychological Status; SD = standard deviation.
All participants underwent a urine drug screen at baseline for cannabis, ethanol, methadone and cocaine. Baseline results were negative, except for 1 member of the CHR group with a positive result for benzodiazepine, and 4 members of the CHR group with a positive result for cannabis.
Participants at clinical high risk for psychosis who were currently on antipsychotic treatment: 0.5 mg risperidone (n = 1), 1.0 mg risperidone (n = 2), 75 mg quetiapine (n = 1), and 5 mg aripiprazole (n = 1).
Score missing for 2 participants.