Only 75% of the 10308 participants were asked to complete the hostility scale at phase 1 due to this measure being introduced after the start of the baseline survey. 6484 participants responded to the hostility questions (84% of those asked). 6012 participants at Phase 7 responded to the CES-D Scale; 3639 of these had data cynical hostility. Finally, 3399 participants had complete data on cynical hostility, depressive mood and the 13 covariates. The mean age (SD) at baseline was 44 (5.9) years. The prevalence of depressive mood among these participants at phase 7 was 15.1%.
shows the associations between covariates (Phase 1), cynical hostility (Phase 1) and depressive mood (Phase 7). Higher cynical hostility scores were associated with younger age, lower socioeconomic position, being non-white, higher BMI, antidepressant medication intake, having common mental disorders, higher number of SL-E, lower social network size, and higher social isolation (all p ≤ 0.007). The presence of depressive mood at Phase 7 was associated with being female, younger age, lower socioeconomic position, being non-white, lower alcohol consumption, lower exercise, antidepressant medication, having common mental disorders, higher number of SL-E, and lower confiding/emotional support score at baseline (all p<0.001).
| Table 1Bivariate associations of sample characteristics at baseline (phase 1) with cynical hostility score levels (phase 1) and depressive mood (phase 7), n=3399†. |
presents the association between cynical hostility at baseline (Phase 1) and depressive mood over 19 years later (Phase 7). In model 2, adjusting for sex, age, ethnicity and socioeconomic position, participants in the second quartile of cynical hostility had 1.58 times greater odds (95% CI; 1.14–2.20) of depressive mood compared to those in the first quartile. Those in the third (OR=2.78; 95% CI, 2.03–3.77) and fourth quartile (OR=4.66; 95% CI, 3.41–6.36) also had a greater likelihood of depressive mood when compared to those in the lowest quartile. Further adjustment for health-related behaviours in model 3 (BMI, alcohol consumption and exercise) did not much change these associations. In Model 4a, when further adjustment was made for baseline SL-E and confiding/emotional support score, the associations were attenuated, particularly for participants in the highest cynical hostility quartile (16% compared to model 2). In model 4b, when further adjustment was made for SL-E and confiding/emotional support score at the baseline and during the follow-up, a similar percentage of attenuation was observed. Finally, further adjustments (model 5) for antidepressant medication intake and common mental disorders at baseline, the odds of depressive mood at follow up was reduced, particularly for participants in the highest cynical hostility level (17% compared to model 3). However, the dose response association between cynical hostility levels and depressive mood was preserved even in the fully adjusted models. In the table we also present the association between cynical distrust and depressive mood. As with cynical hostility, we found evidence of a dose-response association between levels of cynical distrust and the likelihood of depressive mood at follow-up.
| Table 2Association of hostility (phase 1) with depressive mood (phase 7), n of depressive participants/n all participants = 513/3399. |
Sensitivity analyses
To test the robustness of the present findings, we examined the predictive value of hostility on depressive mood among participants with no mental health difficulties (common mental disorders or antidepressant medication) at study baseline (phase 1). After excluding participants who reported common mental disorders and antidepressant medication at baseline (phase 1), the number of participants with depressive mood at follow decreased by 49% to 260. Nevertheless, the magnitude of the association between cynical hostility and depressive mood at follow-up was similar to that observed in the full sample. Participants in the second quartile of cynical hostility had 1.41 times greater odds (95% CI; 0.93–2.12) of depressive mood compared to those in the first quartile. Those in the third (OR=2.30; 95% CI, 1.57–3.37) and fourth quartile (OR=3.39; 95% CI, 2.27–5.07) also had greater likelihood of depressive mood, suggesting that cynical hostility is a strong predictor depressive mood even in individuals free of mental health difficulties at baseline.
Cynical distrust was also assessed at phase 5 of the study; analysis with this measure revealed that it also predicted depressive mood at follow-up, despite the shortened follow-up time (9 years instead of 19): participants in the second quartile of cynical distrust at phase 5 had 1.58 greater odds (95% CI; 2.21–2.05) of depressive mood compared to those in the first quartile. Those in the third (OR=2.03; 95% CI, 1.61–2.56) and fourth quartile (OR=4.06; 95% CI, 3.19–5.17) also had a greater likelihood of depressive mood, suggesting that cynical distrust is a strong and consistent predictor of depressive mood.