Table 1.
Subject data from thirteen protocols were included in the present study. Protocols varied in terms of dependencies necessary for inclusion, exclusionary dependencies, and whether or not subjects were treatment seeking and the version of the delay discounting task administered.
| Protocol | Primary substance use | N | Other dependences possible? | Treatment seeking | Discounting version |
|---|---|---|---|---|---|
| 1 | None (Control) | 61 | No | N/A | 1 |
| 2 | Nicotine | 24 | No | No | 2 |
| 3 | Nicotine | 20 | No | No | 1 |
| 4 | Nicotine | 13 | No | No | 1 |
| 5 | Cocaine | 71 | Yes (nicotine and marijuana only) | No | 3 |
| 6 | Nicotine | 27 | N | No | 2 |
| 7 | Nicotine | 9 | N | No | 1 |
| 8 | Alcohol | 56 | Yes (nicotine only) | No | 1 |
| 9 | Nicotine | 15 | No | No | 2 |
| 10 | None (Control) | 15 | No | N/A | 5 |
| 11 | Nicotine | 7 | No | No | 4 |
| 12 | Alcohol and/or cocaine | 272 | Yes (any substances) | Yes | 1 |
| 13 | Nicotine | 9 | No | No | 4 |
Discounting Task 1: Delays of 1 day, 1 week, 1 month, 6 months, 1 year, 5 years, 25 years with blocked delays presented in chronological order
Discounting Task 2: Delays of 1 day, 1 week, 1 month, 6 months, 1 year, and 5 years with blocked delays presented in a random order
Discounting Task 3: Delays of 1 day, 1 week, 1 month, 3 months, 6 months, and 1 year with blocked delays presented in a random order
Discounting Task 4: Delays of 1 day, 1 week, 1 month, 6 months, 1 year, 5 years, and 25 years with blocked delays presented in a random order
Discounting Task 5: Variable delays determined by k value calculated from brief 5-item discounting task; blocked delays are then presented in a random order