Cognitive Behavioral Therapy for Insomnia as Treatment for Post-Concussive Symptoms

Postconcussive symptoms (PCS) are frequently reported in those who have sustained traumatic brain injury and there are few evidence-based treatments available following the acute recovery phase. PCS includes a range of symptoms, and therefore, rehabilitation has focused more broadly on cognitive, emotional, and/or physical complaints. A common presentation with PCS is sleep concerns or insomnia, which may represent a more definitive cluster of symptoms for treatment interventions to target and enhance recovery. At present, little is known about the impact of treating sleep concerns on the expression of PCS. Therefore, the current study examined the degree to which PCS improved with treatment focused on insomnia, specifically Cognitive Behavioral Therapy for Insomnia (CBTI). In a primary care setting, thirty Veterans seeking treatment for insomnia completed measures of PCS, mood, and sleep-related variables both before and after CBTI treatment. Results suggested statistically significant and clinically meaningful improvements in PCS symptoms, depression and anxiety, and sleep-related variables in the whole sample and among those with a history of TBI. Important reductions with sleep medication were observed as well. Given these findings, targeting insomnia may represent an important focus for interventions to enhance longer term recovery in TBI populations.


INTRODUCTION
Traumatic brain injuries (TBI) of all severity levels are common among military service members returning from recent conflicts in the Middle East [1]. Correspondingly, subjective complaints of postconcussive symptoms (PCS), including of cognitive, emotional, and physical problems, have increasingly demanded clinical attention. Despite the need, few evidencebased treatments are available for PCS following the acute recovery phase [2]. This study aims to examine the effect of one potential evidence-based intervention, cognitive behavioral therapy for insomnia (CBTI) on PCS.
Mild TBI (mTBI), which comprises the bulk of all TBI cases, does not typically lead to long-term impairments beyond what would be expected given premorbid factors and comorbidities [2]. PCS is a cluster of relatively non-specific symptoms that are common among individuals who have sustained head injuries, but are equally common among individuals who present with depression or chronic pain. Research suggests that in the acute and post-acute phase of recovery, PCS can be prevented or reduced with proper rest and/or information on symptom expectation; however, there are little to no empirically supported interventions for PCS in the chronic phase [2].
Sleep problems, a common PCS, are frequent among Veterans, particularly those evaluated for head injuries [3][4][5] with effects lasting for years following the injury [6]. Recent estimates have estimated that approximately ninety percent of Veterans in VA polytrauma clinics have at least mild insomnia and half to two-thirds have at least moderate insomnia [7,8]. Lending support for the notion for the wide-ranging impact of poor sleep, Cantor and colleagues [9] found that sleep problems among those with remote histories of TBI was related to reduced satisfaction with life. Often, in clinical practice, these sleep concerns are overlooked and not identified as an area of clinical intervention among those with head injuries.
CBTI is an empirically validated treatment that uses behavioral conditioning, cognitive restructuring, and sleep hygiene principles to treat insomnia [10,11]. CBTI is gaining a broad evidence base in primary care as well as specialty clinics. With this evidence base, data also suggest that the benefits of CBTI spread to other aspects of functioning, to include anxiety, depression, and symptoms of post-traumatic stress disorder [12,13]. Among Veterans in a polytrauma clinic, the quantity and quality of sleep has been found to affect emotional and cognitive functioning [8]. Moreover, CBTI has augmented other treatment interventions and suggested enhanced outcomes.
For example, adding behavioral therapy for insomnia to usual care for patients with depression and insomnia produced added benefits on sleep and mood measures [14]. Additionally, adding CBTI to a cognitive behavioral intervention for patients managing chronic pain and depression demonstrated improvements in sleep and fatigue as well as with pain related disability and depression [15]. Therefore, it is reasonable to suspect that improving sleep can improve some of the cardinal symptoms of PCS. Limited research has examined therapy for sleep disorders among those with TBI. Ouellet and colleagues [16] found that CBTI was beneficial in a sample of 11 individuals with histories of TBI. In their sample, CBTI produced important benefits in insomnia, as well as physical and emotional functioning.
Instead of employing a multimodal intervention for the myriad of symptoms associated with PCS, this study will examine the degree to which PCS improves with treatment focused on insomnia. The sample includes Veterans with and without a history of head injury. This decision was made because the component symptoms of PCS are not specific to TBI, and because in many cases there are no objective correlates of PCS, only subjective distress. Specific hypotheses include [1] CBTI will result in improved subjective sleep quality, reduced sleepiness, greater sleep efficiency, reduced depression/ anxiety, and a reduction in symptoms that are commonly attributed to concussions [2]. These treatment effects will be observed regardless of whether individuals have sustained concussions in the past.

ISSN: 2689-8365
and chronic pain disorders were generally diagnosed prior to treatment, but CBTI providers confirmed these diagnoses at intake. In every case, prescriptions for sleep medications were made prior to the referral for CBTI, but there were no data available regarding when these medications were initiated. TBI diagnoses were made by the first author based on self-reported injury characteristics. By patient estimates, the onset of insomnia occurred 12.97 12.99 years ago, more specifically patients estimated onset within the past 10 years for 18 Veterans, 11 to 25 years for 8 Veterans, and more than 25 years ago for 4 Veterans. All participants met DSM5 criteria for Insomnia Disorder [18] and reported some type of daytime impairment related to sleeping concerns including daytime fatigue (93.3%), concentration problems (76.7%), and mood difficulties (76.7%).

MATERIALS AND MEASURES
Participants were given the Hospital Anxiety and Depression Scale (HADS) [19], which is a 14-item measure of anxiety and depression at both intake and end of treatment. For both the Anxiety and Depression subscales, scores of 8 to 10 are considered mild, 11 to 14 moderate, and 15 to 21 severe.
Participants were also given the Insomnia Severity Index (ISI) [20], which is a seven-item measure of subjective difficulties with sleep at each session throughout the study. Scores of 8 to 14 are considered mild, 15 to 21 moderate, and 22 to 28 severe. To assess need for sleep, participants were given the Sleep Need Questionnaire [21] at each session throughout the study. Ranges of scores are 4-20 with higher scores indicating subjective desire for more sleep. Participants were also given the Neurobehavioral Symptom Inventory (NSI) [22], which is a self-rating of 22 [23]. Two items do not load unambiguously on any single factor, and are therefore only included in the total score and not on any of the factors. The total score and affective factor score includes one item pertaining to sleep quality. Therefore, this item will be omitted from some analyses below. There are no set standards for quantifying levels of impairment with the NSI. Each item is scored from zero (no problems) to four points (very severe problems). Broadly speaking, CBTI is a family of treatments that employ behavioral conditioning, cognitive restructuring, and sleep hygiene principles to treat insomnia [11,12]. The procedures used in the current study were part of the National VA training on insomnia [12] and the clinicians providing services had completed this training program and consultation.

RESULTS
Participants who completed treatment were compared to those who prematurely dropped out of treatment on demographic variables, initial sleep estimation variables, and initial questionnaire variables. There were no significant differences between completers and non-completers on any variable except for baseline sleep medication. Completers were more 9.33 times more likely to be on sleep medication at baseline than non-completers, X 2 (1)=4.52, p<0.05. Therefore, non-completers were excluded for the remainder of the analyses.   In the chronic phase of TBI, however, repeated evaluations and reassurances might have limited impact [25]. and focused treatment approach that offers the potential for meaningful reduction of chronic PCS.

Analyses of PCS
Although subjective somatic and cognitive improvement was noted, additional research is needed to confirm these findings using more objective methodologies. Research indicates that subjective cognitive functioning is poorly associated with performance on objective neuropsychological testing [27,28].
In a heterogeneous sample of individuals with TBI and sleepwake disorders, Wiseman-Hakes and colleagues [24] found that treatment of the sleep disorders led to improvements in cognitive performance on objective testing. Their results are regarded as preliminary, however, as the study did not employ a control group to account for practice effects. Additional research is needed to examine the effects of CBTI on objective cognitive testing. Yet, the present study does provide preliminary evidence that CBTI is an effective intervention for PCS.

CONCLUSION
CBTI is a promising intervention for reducing the core symptoms of PCS and reducing symptoms of depression and anxiety. Confirmation is needed from randomized clinical trials.

Disclosure Statement
The