Depression, hypomania and dysfunctional sleep-related cognitions as mediators between stress and insomnia : the best advice is not always found on the pillow

A cognitive mediation model was examined to find out how stress, depression, and hypomania precipitate the occurrence of dysfunctional sleep-related cognitions, which in turn lead to insomnia. A total of 862 participants (639 women, 223 men; M age: 24.67 years, SD = 5.91) completed a series of self-report questionnaires assessing perceived stress, depression, hypomania, dysfunctional sleep-related cognitions, and insomnia. Compared to men, women reported higher levels of stress, depression, and insomnia. Women also suffered from more dysfunctional sleep-related cognitions. All variables were intercorrelated. Structural equation analyses showed that the relationship between stress and insomnia was largely mediated by dysfunctional sleep-related cognitions. Links between depression and insomnia were found to be weak when controlled for stress and dysfunctional sleep-related cognitions. The findings support a cognitive model of insomnia. Stress must be seen as a precipitating factor in the onset and maintenance of insomnia. Consequently, competencies to deal with dysfunctional sleep-related cognitions should be fostered in stress management programs. In turn, stress management should be a primary focus in the treatment of insomnia.