Am I (hyper)aroused or anxious? Clinical significance of pre-sleep somatic arousal in young adults

Self-reported somatic arousal remains a challenging clinical construct, particularly because only a subset of patients report symptoms such as racing heart, palpitations or increased body temperature interfering with their sleep. It is unclear whether self-reported somatic arousal is a marker of hyperarousal or co-morbid clinical anxiety in individuals with insomnia. Participants included 196 young adults aged 20.2 ± 1.0 years old who were predominantly females (75%). About 39% of the sample reported subthreshold insomnia, and about 8% reported clinically significant insomnia, based on their Insomnia Severity Index. Participants completed the Pre-Sleep Arousal Scale, Beck Anxiety Inventory, Beck Depression Inventory, Arousal Predisposition Scale, and Ford Insomnia Response to Stress Test. Multivariable stepwise regression assessed which factors were independently associated with pre-sleep cognitive (Pre-Sleep Arousal Scale-Cognitive) and somatic (Pre-Sleep Arousal Scale-Somatic) arousal. Receiver-operating characteristic analysis assessed the predictive value to identify clinically significant anxiety (Beck Anxiety Inventory ≥ 20), insomnia (Insomnia Severity Index ≥ 15) and arousability (Arousal Predisposition Scale ≥ 32). Beck Anxiety Inventory (β = 0.42) was the best single correlate of Pre-Sleep Arousal Scale-Somatic, while Insomnia Severity Index (β = 0.33) was of Pre-Sleep Arousal Scale-Cognitive. A Pre-Sleep Arousal Scale-Somatic score of 12 or more identified those with clinically significant anxiety with 65% specificity and 65% sensitivity, while a cut-off score of 14 increased its sensitivity (86%). Self-reported pre-sleep somatic arousal may be an index of co-morbid clinical anxiety in individuals with insomnia. These findings aid clinicians with assessment and treatment, particularly in the absence of clinical guidelines indicating when somatically focused relaxation techniques should be included as part of multicomponent cognitive behavioural treatment of insomnia.