Table 1. Demographic and self-reported substance use characteristics of the participants.
| MORPHINE | PLACEBO | p value | |
|---|---|---|---|
| N | 40 | 40 | --- |
| Age (years) | 23.1 ± 3.1 | 23.9 ± 3.9 | 0.31 |
| BMI (kg/m2) | 21.4 ± 3.4 | 22.3 ± 2.7 | 0.19 |
| Autism (AQ-k) | 6.5 ± 3.8 | 5.7 ± 3.6 | 0.34 |
| Anxiety (STAI) | 38.1 ± 9.4 | 35.7 ± 8.3 | 0.23 |
| Social Anxiety (LSAS) | 36.7 ± 17.9 | 33.2 ± 19.0 | 0.39 |
| Social Touch Preferences (STQ) | 25.3 ± 9.5 | 27.1 ± 7.7 | 0.36 |
| Alcohol use (%)a | |||
| Never | 7.5 | 7.5 | --- |
| Several times a year | 25 | 30 | --- |
| Several times a month | 42.5 | 35 | --- |
| 1-2 times per week | 22.5 | 27.5 | --- |
| 3-4 times per week | 2.5 | 0 | --- |
| Tobacco use (%)b | |||
| Not smoking | 87.5 | 90 | --- |
| Occasionally (<10 cigarettes per week) | 12.5 | 10 | --- |
| Drug use (% lifetime – % last year)c | |||
| Cannabis | 47.5 – 25 | 60 – 32.5 | --- |
| Tranquilizers | 7.5 – 5 | 5 – 2.5 | --- |
| Stimulants | 25 – 10 | 17.5 – 7.5 | --- |
| Opiates | 7.5 – 0 | 2.5 – 0 | --- |
| Hallucinogens | 12.5 – 2.5 | 12.5 – 2.5 | --- |
| Other | 5 – 2.5 | 2.5 – 0 | --- |
Self-report (“How often do you consume alcohol?”). Participants were excluded if they reported to consume alcohol more than 3-4 times per week and were screened for alcohol abuse/dependence using the Mini-International Neuropsychiatric Interview.
Self-report (“How often do you smoke cigarettes?”). Participants were excluded if they reported to smoke more than 10 cigarettes per week.
Self-report (“For each of the listed substances, please report if you have ever consumed the substance in your lifetime and/or if you have consumed it within the past year.”). Participants were excluded if they reported consumption of opiates within the past year and were screened for illicit substances regular use/abuse/dependence using the Mini-International Neuropsychiatric Interview.