Objective: Social network has been linked to alcohol use disorder in several studies. However, since the majority of such findings are crosssectional,
causal interpretation is difficult. The aim of the present study was to test if social network characteristics predict alcohol use disorder in a prospective design.
Methods: Information on social network and covariates was obtained from 9589 men and women aged 21–99 years in the Copenhagen City Heart Study, followed for registration of alcohol use disorder in the Danish National Patient Registry and the WINALCO database.
Results: Men who lived alone, were separated or divorced or widowers had a higher risk of developing alcohol use disorder: HR among men living alone vs. men not living alone was 2.28 (95% CI: 1.59–3.27), and HR among separated/divorced men vs. married men was 2.55 (95% CI: 1.33–4.89). No such associations were found among women. Frequency of contact with friends was associated with risk of developing alcohol use disorder among both sexes. For example, the HRs were 1.72 (CI 95%: 0.99–3.01) and 2.59 (95% CI: 1.42–4.71) among women who had contact with friends a couple of times per week and daily, respectively, compared with more rarely. Frequency of contact with
family was not associated with risk of developing alcohol use disorder among either sex.
Conclusion: Living alone and not being married or cohabiting with a partner were predictors of developing alcohol use disorder among men. Further, frequent contact with friends was associated with higher risk of alcohol use disorder among both sexes.