The role of anxiety and depression in the development of insomnia: Cross-sectional and prospective analyses

The purpose of this study was to examine the associations between anxiety, depression and insomnia, and to investigate whether anxiety and depression are related to future insomnia. This study employed a combination of a cross-sectional and a prospective design. From a randomly selected sample from the general population (N = 3600), 1936 participants filled out a baseline and 1-year follow-up survey on insomnia, anxiety and depression. Odds ratios (ORs) estimations were used to investigate the associations between anxiety, depression, and insomnia. In the cross-sectional study, anxiety (OR: 4.61) and depression (OR: 2.42) showed moderate to strong associations with insomnia. However, the prospective study showed that anxiety (OR: 3.35) was more strongly related than depression (OR: 1.96) to the development of insomnia 1 year later. While anxiety seems to play a key role in the development of insomnia, depression may be considered as a possible precipitating mechanism but even more likely as a consequence of insomnia.