Self-Reported Clinical Correlates of Insomnia

Objective: to examine clinical correlates of post-accident insomnia.

Background and Aims: survivors of motor vehicle accidents (MVAs) usually report impaired sleep and other symptoms such as persistent pain, depressive symptoms, anxiety, anger, and post-MVA neurological symptoms. We examined how these variables correlate with insomnia.

Materials and Methods: 101 patients (mean age 42.6, SD=14.1, 39 males, 62 females) undergoing psychological assessment after an MVA completed the Insomnia Severity Index, the Rivermead Post-Concussion Symptoms Questionnaire, and the Brief Pain Inventory. We also assessed post-MVA neurological symptoms other than concussion (e.g., hand tremor, tingling, numbness, impaired muscular control over limbs), the current mood (anxiety, depression, anger). We also interviewed our patients about the immediate symptoms of concussion (loss of consciousness, or feeling dazed, stunned, confused, disoriented, or dizzy).

Results: The Insomnia Severity Index (ISI) in our sample ranged from 2 to 28 (mean 22.3, SD=5.3). The psychometric properties of ISI in our sample are satisfactory (Cronbach’s alpha=.88). The insomnia scores correlated moderately with depressive mood (r=.64) and also with the post-concussion syndrome even after the item dealing with impaired sleep was removed from the Rivermead (r=.66). The insomnia also correlated with measures of MVA related pain (r=.41), anxiety (r=.48), and anger (r=.39), post-MVA neurological symptoms other than concussion (r=.36), and with diagnosis of PTSD (r=.50), but not with age and gender (p>.05).

Conclusions: The post-MVA insomnia (as represented by ISI scores) is moderately correlated with the post-concussion syndrome and with depressed mood.

Keywords: insomnia, pain, concussion, post-concussion syndrome, Rivermead scale.