Table 1.
Sample Characteristics
| Family history
|
||||||
|---|---|---|---|---|---|---|
| Negative
|
Positive
|
p Values
|
||||
| Sociability group | High | Low | High | Low | All | Neg/high vs pos/low |
| N (M/F) | 68 (28/40) | 20 (15/5) | 43 (11/32) | 44 (20/24) | ||
| Age (year) | 23 (4) | 23 (0.8) | 24 (0.5) | 24 (0.5) | ||
| Education (year) | 16 (0.3) | 16 (0.5) | 16 (0.3) | 14 (0.3) | 0.006 | 0.005 |
| SES | 49 (1.6) | 49 (2.8) | 43 (2.1) | 43 (2.0) | 0.054 | 0.16 |
| Shipley vocabulary | 30 (0.5) | 30 (0.9) | 30 (0.6) | 28 (0.6) | 0.098 | 0.11 |
| BDI | 3.5 (0.5) | 5.6 (0.1) | 4.7 (0.7) | 7.3 (0.7) | 0.0003 | 0.0001 |
| EPI—Neuroticism | 5.3 (0.5) | 5.4 (1.0) | 6.5 (0.6) | 7.3 (0.6) | 0.09 | 0.09 |
| AUDIT | 2.8 (0.3) | 2.8 (0.6) | 3.5 (0.4) | 3.3 (0.4) | ||
| Cahalan (oz/mo) | 40 (4) | 35 (8) | 48 (5) | 46 (5) | ||
| Caffeine (mg/d) | 126 (19) | 110 (31) | 102 (16) | 160 (28) | ||
| Tobacco (% using weekly) | 9 | 19 | 17 | 21 | ||
| Drug use (n) | 0 | 1 | 1 | 8 | ||
| Failed drug screen n (%) | 0 (0%) | 2 (10%) | 1 (2%) | 7 (16%) | ||
Entries (M, SE) unless given otherwise. SES, Hollingshead & Redlich Socioeconomic Status score. Higher scores reflect higher SES. All scores shown are considered “Middle Class.” Shipley, Shipley Institute of Living vocabulary score. BDI, Beck Depression Inventory. EPI, Eysenck Personality Inventory. AUDIT, Alcohol Use Disorders Identification Test. Caffeine, structured interview, all sources. Drug use, number of subjects in a group who reported the most frequent use of one or more of 11 categories of abused or psychoactive drugs other than alcohol. Drug Screen entries reflect the number of subjects (% of the respective group) who failed a urine drug screen given on days of testing.