Cognitive-emotional hyperarousal in the offspring of parents vulnerable to insomnia: a nuclear family study.

Cognitive-emotional hyperarousal is believed to be a predisposing factor for insomnia; however, there is limited information on the association of familial vulnerability to insomnia and cognitive-emotional hyperarousal. The aim of this study was to estimate the heritability of stress-related insomnia and examine whether parental vulnerability to stress-related insomnia is associated with cognitive-emotional hyperarousal in their offspring. We studied a volunteer sample of 135 nuclear families comprised of 270 middle-aged (51.5 ± 5.4 years) fathers and mothers and one of their biological offspring (n = 135, 20.2 ± 1.1 years). We measured vulnerability to stress-related insomnia (i.e. Ford Insomnia Response to Stress Test: FIRST), perceived stress, depression and anxiety in all participants, and arousability, presleep cognitive and somatic arousal, coping and personality in the offspring. We found a heritability estimate of 29% for FIRST scores. High FIRST parents had three to seven times the odds of having offspring highly vulnerable to stress-related insomnia. Offspring of high FIRST parents showed higher arousability, presleep cognitive arousal and emotion-oriented coping. Furthermore, high FIRST mothers contributed to offspring's higher anxiety and lower task-oriented coping, while high FIRST fathers contributed to offspring's higher presleep somatic arousal and conscientiousness. Vulnerability to stress-related insomnia is significantly heritable. Parents vulnerable to stress-related insomnia have offspring with cognitive-emotional hyperarousal who rely upon emotion-oriented coping. These data give support to the notion that arousability and maladaptive coping are key factors in the aetiology of insomnia.