The Interaction of Sleep and Mood During Recovery from Mild Traumatic Brain Injury

Insomnia and depression are common co-morbidities associated with mild traumatic brain injury (mTBI). Data from Transforming Research and Clinical Knowledge in TBI, a longitudinal cohort study of TBI and orthopedic controls (OTC), were used to examine insomnia trajectories and the temporal relationship between insomnia and depressive symptoms during recovery. mTBI (<i>n</i> = 1,557) and OTC (<i>n</i> = 226) adult patients with no psychiatric or sleep disorder history were assessed at 2 weeks and 3, 6, and 12 months post-injury, and at three long-term assessments between 2 and 10 years post-injury. Latent class growth analysis identified five insomnia trajectory classes during the first year post-injury, revealing 25% with persistent insomnia, 4% improving, and 71% below the clinical cutoff. A random intercept cross-lagged panel model tested the lagged effects between insomnia and depression. In addition to being longitudinally correlated (φ = 0.74, <i>p</i> < 0.001), depressive symptomatology operated as a leading indicator of worsening insomnia from 3 to 6 months post-injury (β = 0.20, <i>p</i> = 0.001) across the whole sample. The multigroup model revealed less insomnia (α = -0.31, <i>p</i> = 0.006) and depressive symptoms (α = -0.52, <i>p</i> < 0.001) in OTC relative to mTBI. From 1 to 5-10 years post-injury, mTBI low insomnia classes remained stable, while the highest class improved moderately (-5.50, 95% confidence interval: -7.84, -3.16, <i>p</i> < 0.001). Our findings suggest depressive symptoms may lead to worsening insomnia during the subacute recovery period and that a subset of patients with mTBI may suffer from new-onset insomnia that persists for more than 5 years.