Table 2.
Multinomial logistic regression for the association (OR, 95%CI) between psychiatric disorders and heaviness of cannabis use and classesa of subjective effects to cannabis among 464 offspring who used cannabis at least once.
| Class 1 (high responder) vs. Class 4 (low responder) |
Class 2 (positive responder) vs. Class 4 (low responder) |
Class 3 (mixed/relaxed) vs. Class 4 (low responder) |
|
|---|---|---|---|
| Familial risk | |||
| 4-Group designb | |||
| Group 1 HG–HE | 0.87 (0.30–2.51) | 0.78 (0.28–2.18) | 0.84 (0.32–2.17) |
| Group 2 HE–LE | 0.55 (0.13–2.38) | 0.67 (0.14–3.17) | 0.38 (0.10–1.49) |
| Group 3 MG–LE | 1.00 (0.21–4.80) | 2.09 (0.48–9.13) | 1.43 (0.36–5.78) |
| Group 4 LG–LE | 1.0 | 1.0 | 1.0 |
| Maternal cannabis abuse/dependence | 0.59 (0.10–3.47) | 1.09 (0.19–6.28) | 1.22 (0.25–6.04) |
| Maternal data missing | 0.39 (0.16–0.95) | 0.58 (0.24–1.40) | 0.49 (0.19–1.24) |
| Sododemographics | |||
| Age | 0.93 (0.85–1.01) | 0.98 (0.90–1.07) | 0.97 (0.88–1.06) |
| Male gender | 2.30 (1.10–4.81)a | 2.28 (1.05–4.98)a | 1.12 (0.54–2.30)b |
| White | 1.26 (0.55–2.90) | 0.76 (0.33–1.75) | 0.94 (0.41–2.14) |
| Paternal household income | |||
| ≤20,000 | 1.84 (0.17–20.20) | 3.59 (0.42–30.58) | 1.54 (0.15–16.08) |
| 20,001–100,000 | 1.0 | 1.0 | 1.0 |
| >100,000 | 0.52 (0.21–1.33) | 0.61 (0.23–1.60) | 0.61 (0.23–1.57) |
| Used illegal drugs other than cannabis | 1.67 (0.65–4.33) | 0.98 (0.37–2.58) | 1.66 (0.64–4.35) |
| Heaviness of cannabis use | |||
| Number of times used cannabis | |||
| <6 times | 1.0 | 1.0 | 1.0 |
| 6–40 times | 10.71 (3.53–32.47) | 10.45 (3.44–31.71) | 6.99 (2.29–21.31) |
| >40 times | 11.78 (3.84–36.10)a | 5.00 (1.57–15.98)b | 3.02 (1.00–9.13)b |
a and b—post hoc contrasts: within rows, odds ratios with different letters (a and b) are significantly different, p < 0.05.
The significance is the OR and 95%CI. Readers will use the CI to interpret significance.
Class 1—high responder, Class 2—positive responders, Class 3—mixed/relaxed, Class 4—low responder.
4-Group design: Group 1—offspring at high genetic (HG) and high environmental (HE) risk because fathers are MZ and DZ twins with DSM-III-R illicit drug dependence; Group 2—offspring at high genetic (HG) and low environmental (LE) risk because fathers are unaffected MZ twins with DSM-III-R illicit drug dependent co-twins: Group 3—offspring at medium genetic (MG) and LE risk because fathers are unaffected DZ with DSM-III-R illicit drug dependent co-twins: Group 4—offspring at low genetic and LE because fathers are unaffected MZ and DZ control pairs.