Gender differences in the bidirectional relationship between alcohol consumption and sleeplessness: the Tromsø study.

Background: The degree to which the relationship between alcohol use and sleeplessness is unidirectional or reciprocal is unclear due to great variation among the results of previous studies. The aim of the present study was to investigate if the relationship between alcohol use and sleeplessness is bidirectional by exploring how the change in and stability of alcohol use were related to sleeplessness, and vice versa, how the change in and stability of sleeplessness were related to alcohol use, in a longitudinal study spanning 13 years.

Method: Data were collected from 9941 adults who participated in two waves (T1: 1994-1995, and T2: 2007-2008) of the Tromsø Study, a Norwegian general population health study.