The Relations of Cognitive, Behavioral, and Physical Activity Variables to Depression Severity in Traumatic Brain Injury: Reanalysis of Data From a Randomized Controlled Trial

Relationship among depression, fatigue, and sleep after traumatic brain injury: The role of physical exercise as a non-pharmacological therapy

Traumatic brain injury (TBI) is a burdensome condition frequently associated with an increased risk of psychiatric disorders. Although the exact molecular signaling pathways have not yet been fully defined, the compromised integrity of functional brain networks in regions such as the prefrontal cortex and anterior cingulate cortex has been linked to persistent symptoms, including depression, fatigue, and sleep disorders. Understanding how TBI affects neural physiology enables the development of effective interventions. One such strategy may be physical exercise, which promotes neural repair and behavioral rehabilitation after TBI. However, there are caveats to consider when interpreting the effects of physical exercise on TBI-induced mental health issues. This review will highlight the main findings from the literature investigating how different physical exercise protocols affect the progression of TBI-induced depression, fatigue, and sleep disturbances. Furthermore, we aim to explore potential neurobiological pathways that explain how physical exercise influences depression, fatigue, and sleep following TBI.

Cognitive vulnerabilities and depressed mood in acquired brain injury

ABSTRACTAcquired Brain Injury (ABI), an important cause of long-term disability, is associated with increased rates of depression in addition to common cognitive and physical consequences. Past research has linked post-ABI depression to injury severity (e.g., extent of physical or cognitive impairment) and premorbid mood problems. In the general (non-ABI) population, depression is associated with cognitive vulnerabilities that have informed the development of psychological interventions. In this observational study in a heterogeneous sample of individuals with chronic stage ABI, we examine two cognitive vulnerabilities - dysfunctional attitudes (DAs) and autobiographical memory specificity - and explore whether these are linked to depression symptoms and ongoing cognitive difficulties as in the general population. Compared to control participants, individuals with an ABI demonstrated increased endorsement of DAs and reduced specificity of autobiographical memory recall. Within the ABI group, cognitive vulnerability-depression symptom correlations were detected for an explicit measure of DAs, but not for a more implicit DA measure or for autobiographical memory specificity. While individual differences in injury severity and other factors likely obscured subtle relationships between mood and cognitive vulnerabilities, evidence of these vulnerabilities may be relevant to changes in identity and psychological interventions that target low mood in ABI.

Cognitive behavioral therapy for managing depressive and anxiety symptoms after brain injury: a meta-analysis

BACKGROUND

Individuals with traumatic brain injury (TBI) are at increased risk of depression and anxiety, leading to impaired recovery. While cognitive-behavioral therapy (CBT) addresses anxiety and depression maintenance factors, its efficacy among those with TBI has not been clearly demonstrated. This review aims to bridge this gap in the literature.

METHODS

Several databases, including Medline, PsycInfo and EMBASE, were used to identify studies published between 1990 and 2021. Studies were included if: (1) trials were randomized controlled trials (RCT) involving CBT-based intervention targeting anxiety and/or depression; (2) participants experienced brain injury at least 3-months previous; (3) participants were ≥18 years old. An SMD ± SE, 95% CI and heterogeneity were calculated for each outcome.

RESULTS

Thirteen RCTs were included in this meta-analysis. The pooled-sample analyses suggest that CBT interventions had small immediate post-treatment effects on reducing depression (SMD ± SE: 0.391 ± 0.126, p < 0.005) and anxiety (SMD ± SE: 0.247 ± 0.081, p < 0.005). Effects were sustained at a 3-months follow-up for depression. A larger effect for CBT was seen when compared with supportive therapy than control. Another sub-analysis found that individualized CBT resulted in a slightly higher effect compared to group-based CBT.

CONCLUSION

This meta-analysis provides substantial evidence for CBT in managing anxiety and depression post-TBI.

Developing behavioural activation for people with acquired brain injury: a qualitative interpretive description study of barriers and facilitators to activity engagement

BACKGROUND

Acquired brain injuries (ABI) from stroke, head injury, or resected brain tumours are associated with poor emotional wellbeing and heightened risk of mood disorder. Common sequalae of ABI, such as poor attention and memory, can create barriers to the efficacy of cognitively demanding mood interventions, such as Cognitive Behavioural Therapy (CBT). Behavioural Activation (BA), where individuals plan and engage in reinforcing activities, is a promising alternative due to lower cognitive demands. However, BA was initially developed in clinical populations without ABI where the primary barriers to activity engagement were low mood and anxious avoidance. Additionally, BA can incorporate a range of techniques (e.g., mood monitoring, activity scheduling, targeting avoidance, contingency management) and psychoeducational topics (e.g., mindfulness, managing uncertainty; social/communication skills). Exploring barriers and facilitators to adopting specific BA components in ABI is an important aim.

METHODS

Semi-structured interviews were conducted with purposively selected ABI survivors (N = 16) with both low and high depressive symptoms, and family members (N = 7). Questions focused on routine and enjoyable activities, and feedback on 10 different BA techniques and associated psychoeducational topics. Transcripts were analysed using an interpretive description framework. Analysis was informed by field notes, reflexivity diaries, and peer debriefing.

RESULTS

The final constructed framework, Creating Sustainable Engagement, comprises a two-tier hierarchy. Higher-level themes concerned core perspectives of BA, regardless of BA component discussed. This included identifying optimal time windows for different BA components (Right Tool at the Right Time), that BA components should, at least initially, not be burdensome or fatiguing (Perceived Effort), that emotional readiness to confront activity-mood relationships should be addressed (Emotional Impact), and that planned BA activities be consistent with individual values (Relation to Values). Lower-level themes concerned specific BA components: Of these, activity scheduling, procedures targeting avoidance, managing uncertainty and social/communication skills were generally well-received, while mood monitoring, contingency management, and mindfulness had mixed feedback.

CONCLUSIONS

BA is a widely scalable intervention that can be adapted for ABI. This study provides a novel framework on implementing a range of BA components in ABI and adds to the limited evidence on which components may be particularly suitable.

Community mental health interventions for people with major depressive disorder: A scoping review

People with major depressive disorder continue to be marred by chronically pernicious yet preventable outcomes in the biopsychosocial aspects. With the reallocation of healthcare resources towards the fight against the coronavirus 2019 pandemic, much emphasis has been placed on existing community mental health interventions to ameliorate the disruption of mental health services. Moreover, the recent propulsion of community mental health services by the World Health Organization Mental Health Action Plan 2013-2030 ignited the need to bolster existing community interventions by providing comprehensive, responsive and integrated mental healthcare. The enhanced emphasis on mental healthcare in the community and the heightened demands of people with major depressive disorder underscores the need to explore the current state of community mental health interventions. This scoping review examined 51 primary studies published from year 2010 to 2020 using Arskey & O'Malley's five-stage framework and provided an overview of the impact of existing community mental health interventions for people with major depressive disorder. Findings using thematic analysis have recommended the adoption of person-centred community mental healthcare via the biopsychosocial approach for people with major depressive disorder. Enablers of community mental health interventions were driven by culturally appropriate care and augmented by technology-driven modalities. Challenges and gaps of community mental health interventions include the perpetuation of stigma and misconception, complex demands of persons with major depressive disorder and lack of holistic and long-term outcomes. Given the impact of major depressive disorder on the various biopsychosocial aspects, it is envisioned that our insights into the enablers and barriers of community mental health interventions will guide prospective interdisciplinary and nurse-led interventions in holistically improving the care of persons with major depressive disorder in the community settings.

A systematic review on integrated care for traumatic brain injury, mental health, and substance use

Traumatic brain injuries (TBI) and mental health or substance use disorders (MHSU) are global public health concerns due to their prevalence and impact on individuals and societies. However, care for individuals with TBI and MHSU remains fragmented with a lack of appropriate services and supports across the continuum of healthcare. This systematic review provided an evidence-based foundation to inform opportunities to mobilize and adapt existing resources to integrate care for individuals with TBI and MHSU by comprehensively summarizing existing integrated activities and reported barriers and facilitators to care integration. MEDLINE, EMBASE, PsycINFO, CINAHL, Cochrane Central Register of Controlled Trials, Sociological Abstracts, and Dissertations & Theses Global were independently reviewed by two reviewers based on pre-determined eligibility criteria. Data on the integration activity, level and type of integration, reported barriers and facilitators, and the strategies aligning with the World Health Organization’s (WHO) Framework on Integrated Person-Centred Care were extracted to form the basis for a narrative synthesis. Fifty-nine peer-reviewed articles were included, describing treatments (N = 49), programs (N = 4), or screening activities (N = 7). Studies discussing clinical integration at the micro- (N = 38) and meso- (N = 10) levels, service integration at the micro- (N = 6) and meso- (N = 5) levels, and functional integration at the meso-level (N = 1) were identified. A minority of articles reported on facilitators (e.g., cognitive accommodations in treatment plans; N = 7), barriers (e.g., lack of education on cognitive challenges associated with TBI; N = 2), or both (N = 6), related to integrating care. This review demonstrated that integrated TBI and MHSU care already exists across a range of levels and types. Given the finite and competing demands for healthcare resources, cognitive accommodations across treatment plans to facilitate integrated TBI and MHSU care should be considered. Multidisciplinary teams should also be explored to provide opportunities for education among health professionals so they can be familiar with TBI and MHSU.

Trial registration: Prospero Registration: CRD42018108343.

Benefits of physical exercise programs toward people with acquired brain injury: A protocol for systematic review and meta-analysis

BACKGROUND

Exercise has proven to be a tool improving health related quality of life in people with acquired brain injury (ABI) as part of multidisciplinary team during the subacute and chronic phase. While intervention studies and revisions have been increased in recent years, there is no consensus about the type, frequency and variables of control in exercise interventions. Besides, this collective need programs that respond to different functional levels, given the heterogeneity of people with ABI, not only because of the etiology, but also because of the severity differences over their deficits. The aim of this systematic review and meta-analysis is to summarize the evidence regarding the relationship between exercise and health related quality of life in subacute and chronic phase.

METHODS

A protocol of systematic review and meta-analysis will examine the benefits of physical exercise (PE) toward people with ABI will be conducted. A comprehensive search will be conducted in the following electronic databases: MEDLINE, The Cochrane Library, CINAHL, SportDiscus, and Web of Science from inception to July 2020. Independent review authors will evaluate the title and abstract for each trial and disagreements will be solved by discussion with a third author if necessary. Standard pairwise meta-analysis, including heterogeneity analysis, subgroup analysis, and sensitivity analysis, will be performed using the Stata software. The quality evaluation of this study will be completed using the Cochrane collaboration risk of bias tool and the risk of bias assessment will be conducted by the World Health Organization grading of recommendations, assessment, development, and evaluation. The review will be reported in accordance to the preferred reporting items for systematic reviews and meta-analyses statement.

RESULTS AND CONCLUSSION

This systematic review and meta-analysis protocol will provide an overview regarding the benefits of PE on functioning, social participation and quality of life toward people with ABI. The variability of outcomes across PE from the selected studies will provide important information for future trial designs. Results of the proposed review will inform practice and the design of future clinical trials. This study will summarize all the selected trials aimed at estimating the effectiveness of applying physical activity programs to ABI users.Systematic review registration number: PROSPERO CRD42020191779.

Paths to Successful Translation of New Therapies for Severe Traumatic Brain Injury in the Golden Age of Traumatic Brain Injury Research: A Pittsburgh Vision

New neuroprotective therapies for severe traumatic brain injury (TBI) have not translated from pre-clinical to clinical success. Numerous explanations have been suggested in both the pre-clinical and clinical arenas. Coverage of TBI in the lay press has reinvigorated interest, creating a golden age of TBI research with innovative strategies to circumvent roadblocks. We discuss the need for more robust therapies. We present concepts for traditional and novel approaches to defining therapeutic targets. We review lessons learned from the ongoing work of the pre-clinical drug and biomarker screening consortium Operation Brain Trauma Therapy and suggest ways to further enhance pre-clinical consortia. Biomarkers have emerged that empower choice and assessment of target engagement by candidate therapies. Drug combinations may be needed, and it may require moving beyond conventional drug therapies. Precision medicine may also link the right therapy to the right patient, including new approaches to TBI classification beyond the Glasgow Coma Scale or anatomical phenotyping-incorporating new genetic and physiologic approaches. Therapeutic breakthroughs may also come from alternative approaches in clinical investigation (comparative effectiveness, adaptive trial design, use of the electronic medical record, and big data). The full continuum of care must also be represented in translational studies, given the important clinical role of pre-hospital events, extracerebral insults in the intensive care unit, and rehabilitation. TBI research from concussion to coma can cross-pollinate and further advancement of new therapies. Misconceptions can stifle/misdirect TBI research and deserve special attention. Finally, we synthesize an approach to deliver therapeutic breakthroughs in this golden age of TBI research.

Mood, Activity Participation, and Leisure Engagement Satisfaction (MAPLES): a randomised controlled pilot feasibility trial for low mood in acquired brain injury

Background

Acquired brain injury (ABI) affects approximately 79.3 million individuals annually and is linked with elevated rates of depression and low mood. Existing methods for treating depression in ABI have shown mixed efficacy. Behavioural activation (BA) is a potentially promising intervention. Its premise is that individuals with low mood avoid planning and engaging in activities due to low expectations of a positive outcome. Consequently, their exposure to positive reinforcement is reduced, exacerbating low mood. BA aims to break this cycle by encouraging activity planning and engagement. It is unknown whether cognitive demands of traditional BA may undermine efficacy in ABI. Here, we assess the feasibility and acceptability of two groups designed to increase activity engagement. In the activity planning group (traditional BA), the importance of meaningful and positive activity will be discussed and participants encouraged to plan/engage in activities in everyday life. The activity engagement group (experiential BA) instead focuses on engagement in positive experiences (crafts, games, discussion) within the group. The primary aims are to evaluate the feasibility and acceptability of the two groups in ABI. A secondary aim is to explore relative efficacy of the groups compared to an equivalent period of waitlist controls.

Method

This study outlines a parallel-arm pilot feasibility trial for individuals with low mood and ABI that compares a traditional vs experiential BA group vs waitlist controls. Adults (≥ 18 years) will be recruited from local ABI services and randomised to condition. Feasibility and acceptability will be assessed via recruitment, retention, attendance and participant feedback. Groups will be compared (pre- and post-intervention and 1 month follow-up) by assessing self-reported activity engagement. Secondary outcomes include self-report measures of depression, anxiety, post-traumatic distress related to the ABI, motivation, participation and sense of control over one’s life.

Ethics and dissemination

The trial has been approved by the Health Research Authority of the NHS in the UK (East of England—Cambridge Central, REF 18/EE/0305). Results will inform future research on interventions for mood in ABI and be disseminated broadly via peer-reviewed journals, conference presentations and social media.

Trial registration

ClinicalTrials.gov, NCT03874650 pre-results. Protocol version 2.1, March 5, 2019

Getting motivated: long-term perspectives on engaging in community-based programs after acquired brain injury

BACKGROUND

Low motivation is a common problem after acquired brain injury (ABI) and can persist for years after injury. Little is known, however, about perspectives of motivation with respect to engaging in the community, many years after ABI.

PURPOSE

To explore the client with ABI perspective of motivation and engagement in individuals based in community ABI programs.

METHOD

Interpretive description methods were utilized. Semi-structured interviews were conducted with 21 individuals with an ABI.

FINDINGS

Participants felt that both internal factors, such as feelings of hope, and external factors, such as social support, influence levels of motivation to engage. When positive internal and external motivators were enhanced, and negative internal and external motivators reduced, this gave rise to a sense of choice and control, which led to increased engagement.

IMPLICATIONS

Fostering positive aspects of rehabilitation and increasing choice and control may promote engagement. External motivators, such as reducing repetitiveness and promoting peer support, are motivators that community and clinical settings can implement relatively easily, whilst internal motivators such as attitudes toward therapy may need to be addressed continuously to enhance motivation and engagement.

Psychiatric Disorders After Traumatic Brain Injury: A Nationwide Population-Based Cohort Study and the Effects of Rehabilitation Therapies

OBJECTIVE

To investigate the risk of psychiatric disorders after traumatic brain injury (TBI), and to clarify whether the post-TBI rehabilitation was associated with a lower risk of developing psychiatric disorders.

DESIGN

A register-based, retrospective cohort design.

SETTING

Using data from the National Health Insurance Research Database of Taiwan, we established an exposed cohort with TBI and a nonexposed group without TBI matched by age and year of diagnosis between 2000 and 2015.

PARTICIPANTS

This study included 231,894 patients with TBI and 695,682 patients without TBI (N=927,576).

INTERVENTIONS

Rehabilitation therapies in TBI patients.

MAIN OUTCOME MEASURES

A multivariable Cox proportional hazards regression model was used to compare the risk of developing psychiatric disorders.

RESULTS

The incidence rate of psychiatric disorders was higher in the TBI group than the control group. Compared with the control group, the risk of psychiatric disorders in the TBI group was twofold (hazard ratio [HR]=2.072; 95% confidence interval [95% CI], 1.955-2.189; P<.001). Among the participants with TBI, 49,270 (21.25%) had received rehabilitation therapy and had a lower risk of psychiatric disorders (HR=0.691; 95% CI, 0.679-0.703; P<.001). In the subgroup analysis, the medium- to high-level intensity rehabilitation therapy was associated with lower risks of psychiatric disorder (HR=0.712 and 0.568, respectively), but there was no significant finding in the low-intensity group.

CONCLUSIONS

We found that TBI was associated with a high risk for developing psychiatric disorders, and that the post-TBI rehabilitation significantly reduced the risk of psychiatric disorders in a dose-dependent manner.

Behavioral Activation Augmented With Mobile Technology for Depression and Anxiety in Chronic Moderate-Severe Traumatic Brain Injury: Protocol for a Randomized Controlled Trial

Objective

To describe and provide the rationale for a randomized controlled trial for depression or anxiety after moderate to severe traumatic brain injury (TBI), which will test 2 treatments based on behavioral activation (BA), a promising model to promote both positive mood and increased activity in this population.

Design

Randomized controlled trial with masked outcome assessment.

Setting

Outpatient catchment area of 1 TBI treatment center.

Participants

Community-dwelling persons (N=60) with moderate-severe TBI at least 6 months prior to enrollment and greater than mild depression or anxiety.

Interventions

Participants will be randomized 2:1 into an 8-session treatment, behavioral activation with technology, consisting of 6 face-to-face sessions and 2 via phone, with mood and activity monitoring conducted via ecological momentary assessment on a smartphone; or a single session incorporating BA principles followed by 8 weeks of activity reminders in the form of implementation intentions, delivered as text messages.

Main Outcome Measures

Brief Symptom Inventory-18 (primary outcome); Environmental Reward Observation Scale, Behavioral Activation for Depression Scale, Participation Assessment with Recombined Tools-Objective, Diener Satisfaction With Life Scale, Quality of Life after Brain Injury scale, Patient Global Impression of Change. Outcomes are measured midway through intervention, after treatment cessation (primary outcome), and at 2-month follow-up. A treatment enactment interview is administered after the follow-up to ascertain to what extent participants continue to engage in activities and use strategies promoted during trial participation.

Results

N/A.

Conclusions

N/A.

Injury Severity and Depressive Symptoms in a Post-acute Brain Injury Rehabilitation Sample

This study explored the relationship between injury severity and depressive symptoms for treatment-seeking individuals with traumatic brain injury (TBI). The Mayo Classification System was used to classify TBI severity in 72 participants who completed the Patient Health Questionnaire at admission and at dismissal from rehabilitation. Patients with mild TBI reported more depressive symptoms than those with moderate or severe TBI at admission and at dismissal. Although injury severity groups differed by gender composition, gender had no effect on severity of depressive symptoms. All participants reported fewer depressive symptoms at dismissal from rehabilitation, including lower endorsement of dysphoria by discharge. Participants with mild TBI, however, continued to report depressive symptoms of a mild severity at dismissal, with residual problems with anhedonia. These findings underscore the benefit of interdisciplinary post-acute rehabilitation services for persons with TBI of any severity, including those with mild injury.

Activation vs. Experiential Avoidance as a Transdiagnostic Condition of Emotional Distress: An Empirical Study

Background: From a contextual transdiagnostic approach, this study focuses on the importance of the processes of Experiential Avoidance and Activation in explaining and treating psychological problems. There exists widespread empirical evidence to suggest that the response pattern known as Experiential Avoidance, a general unwillingness to remain in contact with particular private experiences through the use of maladaptive avoidance strategies, acts as a functional dimension in various psychological problems. Activation, that is, maintaining contact with experiences/conditions of life and consequently with associated sources of reward, is a condition present in most therapeutic processes. Although a great deal of research has analyzed the relationship of the value of reward with the etiology and maintenance of psychological problems, Activation, as a transdiagnostic factor, has been studied less. The aim of this paper is to carry out an empirical study of the relationship between Activation, EA and emotional state and analyze the capacity of these two conditions to discriminate the intensity and symptomatology type in subjects with emotional distress. Methods: The Hospital Anxiety and Depression Scale (HADS), Environmental Reward Observation Scale (EROS) and Behavioral Activation for Depression Scale (BADS) were completed by 240 health center users. Results: Of the participants, 55% showed clinically relevant emotional distress. All cases of depression showed clinical anxiety. To discriminate between subjects without (n = 109) and with emotional distress (n = 131), analyses of the ROC curves and logistic regression analysis identified the BADS-Avoidance/Rumination followed by the EROS. To discriminate between subjects with anxiety but without depression (n = 61) and with anxiety and depression (n = 70), the most efficient scales were EROS followed by BADS-Social Impairment. Conclusion: It was shown that people with no emotional complaints maintained greater contact with life experiences and with environmental sources of reward than those with emotional distress. Response patterns showing Experiential Avoidance and a reduction in Activation responses were associated with clinical distress. A reduction in Activation was the condition which distinguished those people with the greatest distress and also the greatest comorbidity of symptoms of depression and anxiety. These data support the transdiagnostic nature of Activation and suggest greater attention should be paid to this concept.

Evaluating Machine Learning-Based Automated Personalized Daily Step Goals Delivered Through a Mobile Phone App: Randomized Controlled Trial

Background

Growing evidence shows that fixed, nonpersonalized daily step goals can discourage individuals, resulting in unchanged or even reduced physical activity.

Objective

The aim of this randomized controlled trial (RCT) was to evaluate the efficacy of an automated mobile phone–based personalized and adaptive goal-setting intervention using machine learning as compared with an active control with steady daily step goals of 10,000.

Methods

In this 10-week RCT, 64 participants were recruited via email announcements and were required to attend an initial in-person session. The participants were randomized into either the intervention or active control group with a one-to-one ratio after a run-in period for data collection. A study-developed mobile phone app (which delivers daily step goals using push notifications and allows real-time physical activity monitoring) was installed on each participant’s mobile phone, and participants were asked to keep their phone in a pocket throughout the entire day. Through the app, the intervention group received fully automated adaptively personalized daily step goals, and the control group received constant step goals of 10,000 steps per day. Daily step count was objectively measured by the study-developed mobile phone app.

Results

The mean (SD) age of participants was 41.1 (11.3) years, and 83% (53/64) of participants were female. The baseline demographics between the 2 groups were similar (P>.05). Participants in the intervention group (n=34) had a decrease in mean (SD) daily step count of 390 (490) steps between run-in and 10 weeks, compared with a decrease of 1350 (420) steps among control participants (n=30; P=.03). The net difference in daily steps between the groups was 960 steps (95% CI 90-1830 steps). Both groups had a decrease in daily step count between run-in and 10 weeks because interventions were also provided during run-in and no natural baseline was collected.

Conclusions

The results showed the short-term efficacy of this intervention, which should be formally evaluated in a full-scale RCT with a longer follow-up period.

Trial Registration

ClinicalTrials.gov: NCT02886871; https://clinicaltrials.gov/ct2/show/NCT02886871 (Archived by WebCite at http://www.webcitation.org/6wM1Be1Ng).

Psychiatric phenotypes in chronic traumatic encephalopathy

Chronic traumatic encephalopathy (CTE) is a neurodegenerative disorder involving cognitive, motor, and psychiatrically-relevant symptoms resulting from repetitive head impacts. Psychiatric phenotypes of CTE, including depression and suicidality, present particular challenges for CTE research, given that the diagnosis requires postmortem neuropathological examination. The pathognomonic lesion of CTE is the perivascular accumulation of hyperphosphorylated tau (ptau) protein at the depths of cortical sulci. These lesions are found in the earliest disease stages, and with advancing pathological severity, ptau deposition occurs in widespread brain regions in a four-stage scheme of severity. We review the psychiatric phenotypes of individuals neuropathologically diagnosed with CTE, and suggest that earlier CTE stages hold particular interest for psychiatric CTE research. In the early CTE stages, there is ptau pathology in frontal cortex and axonal loss in the frontal white matter, followed by progressive ptau neurofibrillary degeneration in the amygdala and hippocampus. Neuropathological changes in the frontal and medial temporal lobes may underlie psychiatric phenotypes. Additional insight into the association between CTE pathology and psychiatric sequelae may come from advancements in in vivo methods of CTE detection. Further epidemiological, clinical, and postmortem studies are needed to validate the nature of psychiatric sequelae in CTE.