Table 1.
Demographic, Sleep, and Drug Use Characteristics of the Control Group and Marijuana (MJ) Users
| Demographics | Control Group (n = 14) | MJ Users (n = 17) | t/χ2 | P |
|---|---|---|---|---|
| Age | 21.7 (3.1) [19–30] | 20.6 (2.3) [18–25] | 1.16 | Ns |
| Education | 14.4 (1.3) [14–16] | 11.5 (0.9) [9–13] | 7.19 | 0.01 |
| Mother Education | 13.4 (4.4) [12–18] | 12.3 (3.6) [10–16] | 0.75 | Ns |
| Shipley IQ | 109.5 (6.9) [100–118] | 94.9 (8.5) [85–109] | 5.17 | 0.01 |
| Gender (M/F) | 7/7 | 13/4 | 2.35 | Ns |
| Sleep History Questionnaire Prior to MJ Discontinuance | ||||
| Usual length of time in bed (h) | 7.1 (0.59) | 7.6 (0.57) | −0.69 | Ns |
| Usual hours of actual sleep | 6.5 (0.55) | 6.5 (0.51) | −0.02 | Ns |
| Sleep Satisfaction Score+ | 31 (2.6) | 29 (1.3) | 0.82 | Ns |
| Symptoms Related to Disturbed Sleep+ | 61 (8.5) | 76 (8.2) | −1.27 | Ns |
| Sleep Patterns | ||||
| Horne-Ostberg Index (% of group)F | Morningness 0 | Morningness 18 | 0.331F | Ns |
| Neither 78 | Neither 58 | |||
| Eveningness 22 | Eveningness 24 | |||
| Enter Bed (pre/post)S | 01:32/00:40 | 23:52/00:45 | ||
| Wake Up (pre/post)S | 08:00/08:12 | 08:15/07:45 | ||
| Out of Bed (pre/post)S | 08:43/08:20 | 09:20/08:10 | ||
| Drug Use Variables | ||||
| MJ use (joints/wk) | - | 104 (51) [63–210] | ||
| MJ use duration (yr) | - | 5 (3) [2–12] | ||
| Days/week MJ smoked | 7 | |||
| Alcohol average (drinks/wk) | 2 (2) [0–8] | 3 (4) [0–10] | −0.82 | Ns |
| Alcohol duration (yr) | 2 (2) [0–6] | 2 (2) [0–7] | 0.04 | Ns |
| Cigarettes (currently smoke cigarettes daily) | 1/14 | 3/17 | ||
| Average cigarette use (# cigarettes/day) | [0–1] | [0–2] | ||
| Cigarettes Duration (yr) | 1 (2) [0–4] | 3 (2) [0–6] | −1.32 | Ns |
Note: Numbers are means (SD) [Ranges]; +asked to evaluate sleep during the past few months; the higher the score, the worse the sleep quality; STimes taken from sleep logs (median values); Pre/post = admission for the control group; and MJ discontinuation for the MJ users; FFisher exact test P = 0.331.