Table 4.
Sociodemographic and clinical differences between bipolar disorder individuals whose onset of nicotine dependence was before their onset of bipolar disorder (ND-prior) and those whose onset of bipolar disorder was before their onset of nicotine dependence (BD-prior)
| ND-prior (n = 135) | BD-prior (n = 386) | ORa | 95 % CI | |
|---|---|---|---|---|
|
| ||||
| % (SE) | % (SE) | |||
| Sex: male | 56.5 (5.1) | 47.1 (2.9) | 1.4 | 0.9–2.4 |
| Age | ||||
| 18–29 | 27.9 (4.3) | 36.6 (2.9) | 1.0 | 1.0–1.0 |
| 30–44 | 38.6 (4.6) | 35.9 (3.1) | 1.4 | 0.8–2.5 |
| ≥45 | 33.5 (4.7) | 27.5 (2.6) | 1.6 | 0.9–2.9 |
| Race/ethnicity | ||||
| White non Hispanic | 82.2 (4.3) | 77.4 (2.8) | 1.0 | 1.0–1.0 |
| Other | 17.8 (4.3) | 22.6 (2.8) | 0.7 | 0.4–1.4 |
| Education | ||||
| ≤ High school | 60.7 (4.8) | 53.3 (3.4) | 1.4 | 0.8–2.3 |
| ≥ College | 39.3 (4.8) | 46.7 (3.4) | 1.0 | 1.0–1.0 |
| Marital status | ||||
| Married | 58.3 (4.4) | 48.0 (3.2) | 1.0 | 1.0–1.0 |
| Widowed/divorced/separated | 22.2 (4.2) | 24.1 (2.6) | 0.8 | 0.4–1.3 |
| Never married | 19.6 (3.7) | 27.9 (2.5) | 0.6 | 0.3–0.9 |
| Personal Income | ||||
| $0–19,999 | 54.4 (4.6) | 65.75 (3.2) | 1.0 | 1.0–1.0 |
| $20,000–34,999 | 25.8 (4.0) | 19.7 (2.4) | 1.6 | 0.9–2.6 |
| ≥$35,000 | 19.8 (4.0) | 14.5 (2.1) | 1.7 | 0.8–3.3 |
| Urbanicity: rural | 20.5 (4.6) | 23.4 (3.5) | 0.8 | 0.5–1.5 |
|
| ||||
| Mean (SE) | Mean (SE) | t-test | p-value | |
|
| ||||
| Age of onset of first mood episode, years | 29.7 (1.3) | 18.2 (0.5) | 8.6 | <0.001 |
| Age of first depressive episode, years | 30.4 (1.6) | 21.4 (0.7) | 5.1 | <0.001 |
| Age of first manic episode, years | 30.1 (1.1) | 21.6 (0.6) | 7.0 | <0.001 |
| Number of lifetime depression phases | 6.1 (1.4) | 9.5 (1.1) | −1.9 | 0.061 |
| Number of lifetime manic phases | 4.2 (0.8) | 8.4 (1.0) | −3.2 | 0.002 |
| Age of onset of first full cigarette smoked, years | 14.2 (0.4) | 14.5 (0.2) | −0.6 | 0.555 |
| Age of onset of daily smoking, years | 16.05 (0.4) | 17.5 (0.3) | −3.2 | 0.002 |
| Age of onset of nicotine dependence, years | 20.6 (0.7) | 29.5 (0.7) | −9.8 | <0.001 |
| Number cigarettes smoked per day | 22.7 (1.4) | 20.0 (0.7) | 1.7 | 0.091 |
| Number of withdrawal symptoms | 4.2 (0.2) | 4.4 (0.1) | −0.7 | 0.456 |
| SF-12 | ||||
| Mental Component Summary Score | 44.5 (1.3) | 41.7 (0.8) | 1.8 | 0.072 |
| Physical Disability Scale Score | 48.7 (1.2) | 48.4 (0.7) | 0.2 | 0.847 |
BD-I = bipolar disorder type I; ND-prior = smokers whose age of onset of ND was before their age of onset of first mood episode; BD-prior = smokers whose age of onset of ND was after their age of onset of first mood episode. OR = odds ratio; CI = confidence interval; SE = standard error.
a
Patients whose age of onset of ND was in the same year of age of onset as first mood episode were excluded from analysis.