Table 2.
Associations of standardized values of Fagerström Test for Cigarette Dependence (FTCD) and Brief Wisconsin Inventory of Smoking Dependence Motives (WISDM) measures with depression (CES-D ≥20) among current daily cigarette smokers (n=918 with 163 cases) in the Finnish Twin Cohort. Analyses were performed with logistic regression providing odds ratios (OR) with 95% confidence intervals (CI) including observations without missing values in any variables. In all individual-based analyses, a robust variance estimator was used to adjust for the non-independence of observations within twin pairs. Associations with p-values <0.05 are in bold.
| Individual- based analyses |
Confounders | FTCD | WISDM Dimensions | ||
|---|---|---|---|---|---|
| PDM | AE | Taste | |||
| OR (95% CI) | OR (95% CI) | OR (95% CI) | OR (95% CI) | ||
| Model 1 a | 1.45 (1.20, 1.75) | 1.56 (1.30, 1.87) | 1.54 (1.28, 1.85) | 1.01 (0.85, 1.21) | |
| Model 2 b | Education | 1.44 (1.20, 1.74) | 1.55 (1.29, 1.87) | 1.54 (1.28, 1.85) | 1.02 (0.85, 1.22) |
| Marital status | 1.42 (1.17, 1.72) | 1.54 (1.28, 1.85) | 1.52 (1.26, 1.83) | 1.01 (0.85, 1.20) | |
| Working status | 1.35 (1.11, 1.63) | 1.47 (1.22, 1.80) | 1.49 (1.24, 1.79) | 1.01 (0.85, 1.21) | |
| Self-rated health | 1.19 (0.98, 1.45) | 1.33 (1.10, 1.60) | 1.37 (1.13, 1.66) | 0.99 (0.83, 1.19) | |
| LTPA | 1.42 (1.17, 1.71) | 1.53 (1.27, 1.85) | 1.52 (1.26, 1.82) | 1.01 (0.85, 1.21) | |
| Alcohol consumption | 1.44 (1.19, 1.74) | 1.55 (1.29, 1.86) | 1.53 (1.27, 1.84) | 1.01 (0.84, 1.21) | |
| Pass outs due to alcohol | 1.39 (1.15, 1.68) | 1.50 (1.25, 1.80) | 1.48 (1.23, 1.78) | 0.97 (0.81, 1.17) | |
| Number of cigarettes | 1.51 (1.19, 1.93) | 1.61 (1.29, 2.01) | 1.50 (1.23, 1.83) | 0.95 (0.79, 1.15) | |
| Sleep length | 1.41 (1.17, 1.71) | 1.54 (1.28, 1.85) | 1.50 (1.25, 1.81) | 1.00 (0.84, 1.19) | |
| Sleep quality | 1.41 (1.16, 1.72) | 1.53 (1.27, 1.85) | 1.49 (1.23, 1.80) | 1.03 (0.85, 1.24) | |
| Life satisfaction | 1.19 (0.97, 1.46) | 1.33 (1.09, 1.62) | 1.41 (1.13, 1.76) | 0.93 (0.75, 1.14) | |
| Emotional support | 1.38 (1.14, 1.66) | 1.51 (1.25, 1.81) | 1.51 (1.25, 1.82) | 1.03 (0.85, 1.24) | |
| Negative life events | 1.41 (1.16, 1.16) | 1.51 (1.25, 1.82) | 1.46 (1.21, 1.77) | 0.99 (0.82, 1.20) | |
| Traffic accident in adulthood * | 1.45 (1.20, 1.75) | 1.56 (1.29, 1.87) | 1.53 (1.28, 1.84) | 1.01 (0.85, 1.21) | |
| Physical assault in adulthood * | 1.40 (1.16, 1.69) | 1.51 (1.26, 1.81) | 1.49 (1.24, 1.80) | 1.00 (0.84, 1.20) | |
| Sexual abuse in childhood * | 1.45 (1.20, 1.75) | 1.57 (1.30, 1.88) | 1.51 (1.25, 1.81) | 1.01 (0.84, 1.21) | |
| Sexual abuse in adulthood * | 1.40 (1.15, 1.69) | 1.53 (1.27, 1.84) | 1.52 (1.25, 1.84) | 1.02 (0.85, 1.22) | |
| Victim/witness of violent crime in adulthood * | 1.43 (1.19, 1.72) | 1.54 (1.28, 1.85) | 1.50 (1.25, 1.81) | 1.03 (0.86, 1.23) | |
| Parental divorce in childhood * | 1.44 (1.20, 1.74) | 1.56 (1.30, 1.88) | 1.54 (1.29, 1.85) | 1.01 (0.85, 1.21) | |
| Dichotomy of traumatic life events (none/at least one) ** | 1.39 (1.15, 1.68) | 1.52 (1.26, 1.83) | 1.51 (1.26, 1.82) | 1.01 (0.85, 1.21) | |
| Neuroticism | 1.13 (0.93, 1.39) | 1.12 (0.91, 1.38) | 1.09 (0.88, 1.35) | 0.97 (0.78, 1.20) | |
| Model 3 c | 1.45 (1.09, 1.93) | 1.51 (1.13, 2.03) | 0.66 (0.52, 0.83) | ||
| Model 4 d | 1.09 (0.77, 1.54) | 1.42 (1.06, 1.92) | 1.36 (1.02, 1.82) | 0.87 (0.66, 1.14) | |
| Model 5 e | 0.98 (0.68, 1.40) | 1.16 (0.84, 1.62) | 1.10 (0.81, 1.50) | 0.82 (0.60, 1.12) | |
Fagerström Test for Cigarette Dependence (FTCD); Brief Wisconsin Inventory of Smoking Dependence Motives (WISDM); Primary Dependence Motives (PDM), Affective Enhancement (AE); Taste (T); OR=Odds Ratio; CI=Confidence Interval; n=number of Individuals with Depression in the Analysis by Dependence Motive; LTPA=leisure time physical activity. Depression defined by the Center for Epidemiologic Studies Depression (CES-D) scale with a cut-off value of 20 (Depression CESD ≥20).
Model 1: Individual models for FTCD and each WISDM dimension, adjusted for age and sex (basic model).
Model 2: Individual models for FTCD and each WISDM dimension, adjusted for age, sex and separately for each significant covariate.
Model 3: A multiple adjusted model with all three WISDM dimensions, adjusted for age and sex.
Model 4: Individual multiple adjusted models for FTCD and each WISDM dimension, with all confounders except neuroticism. All traumatic life events * related to depression and smoking dependence/motives were added to the model as a dichotomous variable ** (none vs at least one traumatic life event).
Model 5: Individual multiple adjusted models for FTCD and each WISDM dimension with all confounders (as in the model 4) including also neuroticism.