Effects of Depression and Antidepressant Use on Cognitive Deficits and Functional Cognition Following Severe Traumatic Brain Injury

The Relationship Between Cognitive Functioning and Symptoms of Depression, Anxiety, and Post-Traumatic Stress Disorder in Adults with a Traumatic Brain Injury: a Meta-Analysis

A thorough understanding of the relationship between cognitive test performance and symptoms of depression, anxiety, or post-traumatic stress disorder (PTSD) in people with traumatic brain injury (TBI) is important given the high prevalence of these emotional symptoms following injury. It is also important to understand whether these relationships are affected by TBI severity, and the validity of test performance and symptom report. This meta-analysis was conducted to investigate whether these symptoms are associated with cognitive test performance alterations in adults with a TBI. This meta-analysis was prospectively registered on the PROSPERO International Prospective Register of Systematic Reviews website (registration number: CRD42018089194). The electronic databases Medline, PsycINFO, and CINAHL were searched for journal articles published up until May 2020. In total, 61 studies were included, which enabled calculation of pooled effect sizes for the cognitive domains of immediate memory (verbal and visual), recent memory (verbal and visual), attention, executive function, processing speed, and language. Depression had a small, negative relationship with most cognitive domains. These relationships remained, for the most part, when samples with mild TBI (mTBI)-only were analysed separately, but not for samples with more severe TBI (sTBI)-only. A similar pattern of results was found in the anxiety analysis. PTSD had a small, negative relationship with verbal memory, in samples with mTBI-only. No data were available for the PTSD analysis with sTBI samples. Moderator analyses indicated that the relationships between emotional symptoms and cognitive test performance may be impacted to some degree by exclusion of participants with atypical performance on performance validity tests (PVTs) or symptom validity tests (SVTs), however there were small study numbers and changes in effect size were not statistically significant. These findings are useful in synthesising what is currently known about the relationship between cognitive test performance and emotional symptoms in adults with TBI, demonstrating significant, albeit small, relationships between emotional symptoms and cognitive test performance in multiple domains, in non-military samples. Some of these relationships appeared to be mildly impacted by controlling for performance validity or symptom validity, however this was based on the relatively few studies using validity tests. More research including PVTs and SVTs whilst examining the relationship between emotional symptoms and cognitive outcomes is needed.

Early chronic systemic inflammation and associations with cognitive performance after moderate to severe TBI

BACKGROUND

Cognitive dysfunction adversely effects multiple functional outcomes and social roles after TBI. We hypothesize that chronic systemic inflammation exacerbates cognitive deficits post-injury and diminishes functional cognition and quality of life (QOL). Yet few studies have examined relationships between inflammation and cognition after TBI. Associations between early chronic serum inflammatory biomarker levels, cognitive outcomes, and QOL 6-months and 12-months after moderate-to-severe TBI were identified using unweighted (uILS) and weighted (wILS) inflammatory load score (ILS) formation.

METHODS

Adults with moderate-to-severe TBI (n ​= ​157) completed neuropsychological testing, the Functional Impairment Measure Cognitive Subscale (FIM-Cog) and self-reported Percent Back to Normal scale 6 months (n ​= ​139) and 12 months (n ​= ​136) post-injury. Serial serum samples were collected 1-3 months post-TBI. Cognitive composite scores were created as equally weighted means of T-scores derived from a multidimensional neuropsychological test battery. Median inflammatory marker levels associated with 6-month and 12-month cognitive composite T-scores (p ​< ​0.10) were selected for ILS formation. Markers were quartiled, and quartile ranks were summed to generate an uILS. Marker-specific β-weights were derived using penalized ridge regression, multiplied by standardized marker levels, and summed to generate a wILS. ILS associations with cognitive composite scores were assessed using multivariable linear regression. Structural equation models assessed ILS influences on functional cognition and QOL using 12-month FIM-Cog and Percent Back to Normal scales.

RESULTS

ILS component markers included: IL-1β, TNF-α, sIL-4R, sIL-6R, RANTES, and MIP-1β. Increased sIL-4R levels were positively associated with overall cognitive composite T-scores in bivariate analyses, while remaining ILS markers were negatively associated with cognition. Multivariable receiver operator curves (ROC) showed uILS added 14.98% and 31.93% relative improvement in variance captured compared to the covariates only base model (age, sex, education, Glasgow Coma Scale score) when predicting cognitive composite scores at 6 and 12 months, respectively; wILS added 33.99% and 36.87% relative improvement in variance captured. Cognitive composite mediated wILS associations with FIM-Cog scores at 12 months, and both cognitive composite and FIM-Cog scores mediated wILS associations with QOL.

CONCLUSIONS

Early chronic inflammatory burden is associated with cognitive performance post-TBI. wILS explains greater variance in cognitive composite T-scores than uILS. Linking inflammatory burden associated with cognitive deficits to functional outcome post-TBI demonstrates the potential impact of immunotherapy interventions aimed at improving cognitive recovery post-TBI.

Efficacy and Harms of Pharmacological Interventions for Anxiety after Traumatic Brain Injury: Systematic Review

After a traumatic brain injury (TBI), many persons experience significant and debilitating problems with anxiety. The aim of this systematic review was to critically evaluate the evidence regarding efficacy of pharmacological interventions for anxiety after TBI. We reviewed studies published in English before July 2020 and included original research on pharmacological interventions for anxiety after TBI in adults ≥16 years of age. MEDLINE, PubMed, CINAHL, EMBASE, PsycINFO, and CENTRAL databases were searched, with additional searching of key journals, clinical trials registries, and international drug regulators. The primary outcomes of interest were reduction in symptoms of anxiety and occurrence of harms. The secondary outcomes of interest were changes in depression, cognition, quality of life, and participation. Data were summarized in a narrative synthesis, and evidence quality was assessed using the Cochrane Risk of Bias tool. Only a single non-peer-reviewed, randomized controlled trial of 19 male military service members with mild TBI met inclusion criteria. This study found no significant effect of citalopram on anxiety symptoms over a 12-week intervention. The trial was stopped early because of poor recruitment, and much of the study detail was not included in the report. The methodological quality of the study was difficult to assess because of the lack of detail. No recommendations could be drawn from this review. There is a critical need for adequately powered and controlled studies of pharmacological interventions for anxiety after TBI across all severities that examine side-effect profiles and consider issues of comorbidity and effects of long-term pharmacotherapy.

Interrelationships Between Post-TBI Employment and Substance Abuse: A Cross-lagged Structural Equation Modeling Analysis

OBJECTIVE

To describe the interrelationship of postinjury employment and substance abuse (SA) among individuals with traumatic brain injury.

DESIGN

Structural equation model (SEM) and logistic regression analytic approach using a merged database of the National Trauma Data Bank (NTDB) and Traumatic Brain Injury Model Systems (TBIMS) National Database, with acute care and rehabilitation hospitalization data and 1, 2, and 5 year follow-up data.

SETTING

United States Level I/II trauma centers and inpatient rehabilitation centers with telephone follow-up.

PARTICIPANTS

Individuals in the TBIMS National Database successfully matched to their NTDB data, aged 18-59 years, with trauma severity, age, sex, employment, and SA data at 1, 2, and/or 5 years postinjury (N=2890).

INTERVENTIONS

Not applicable.

MAIN OUTCOME MEASURE

Employment status (employed/unemployed) and SA (present/absent) at year 1, year 2, and year 5 postinjury.

RESULTS

SEM analysis showed older age at injury predicted lower likelihood of employment at all time points postinjury (βYR1=-0.016; βYR2=-0.006; βYR5=-0.016; all P<.001), while higher injury severity score (ISS) predicted lower likelihood of employment (β=-0.008; P=.027) and SA (β=-0.007; P=.050) at year 1. Male sex predicted higher likelihood of SA at each follow-up (βYR1=0.227; βYR2=0.184; βYR5=0.161; all P<.100). Despite associations of preinjury unemployment with higher preinjury SA, postinjury employment at year 1 predicted SA at year 2 (β=0.118; P=.028). Employment and SA during the previous follow-up period predicted subsequent employment and SA, respectively.

CONCLUSIONS

Employment and SA have unique longitudinal interrelationships and are additionally influenced by age, sex, and ISS. The present work suggests the need for more research on causal, confounding, and mediating factors and appropriate screening and intervention tools that minimize SA and facilitate successful employment-related outcomes.

Depression Comorbid With Stroke, Traumatic Brain Injury, Parkinson's Disease, and Multiple Sclerosis: Diagnosis and Treatment

Depression is common among patients with neurologic disorders, and it has long been considered more difficult to treat than depression in the general population. In this review, the authors consider challenges in the diagnosis and treatment of depression among patients with stroke, traumatic brain injury, Parkinson's disease, and multiple sclerosis. For each disorder, the authors discuss the epidemiology and time course of depression as well as review the physiologic and psychological etiologies of depression. In addition, for each disorder, they review screening tools and diagnostic considerations, including differential diagnosis; discuss etiological factors, both neurobiological and psychological; and assess evidence for various depression treatments, including pharmacologic, psychosocial, and neuromodulatory therapies. The evidence suggests that depression is common among patients with neurologic disorders and that it is crucial for general psychiatrists to provide treatment for this population.

TBI Rehabilomics Research: Conceptualizing a humoral triad for designing effective rehabilitation interventions

Most areas of medicine use biomarkers in some capacity to aid in understanding how personal biology informs clinical care. This article draws upon the Rehabilomics research model as a translational framework for programs of precision rehabilitation and intervention research focused on linking personal biology to treatment response using biopsychosocial constructs that broadly represent function and that can be applied to many clinical populations with disability. The summary applies the Rehabilomics research framework to the population with traumatic brain injury (TBI) and emphasizes a broad vision for biomarker inclusion, beyond typical brain-derived biomarkers, to capture and/or reflect important neurological and non-neurological pathology associated with TBI as a chronic condition. Humoral signaling molecules are explored as important signaling and regulatory drivers of these chronic conditions and their impact on function. Importantly, secondary injury cascades involved in the humoral triad are influenced by the systemic response to TBI and the development of non-neurological organ dysfunction (NNOD). Biomarkers have been successfully leveraged in other medical fields to inform pre-randomization patient selection for clinical trials, however, this practice largely has not been utilized in TBI research. As such, the applicability of the Rehabilomics research model to contemporary clinical trials and comparative effectiveness research designs for neurological and rehabilitation populations is emphasized. Potential points of intervention to modify inflammation, hormonal, or neurotrophic support through rehabilitation interventions are discussed. This article is part of the Special Issue entitled "Novel Treatments for Traumatic Brain Injury".

Employment Stability in the First 5 Years After Moderate-to-Severe Traumatic Brain Injury

OBJECTIVE

To characterize employment stability and identify predictive factors of employment stability in working-age individuals after moderate-to-severe traumatic brain injury (TBI) that may be clinically addressed.

DESIGN

Longitudinal observational study of an inception cohort from the Traumatic Brain Injury Model Systems National Database (TBIMS-NDB) using data at years 1, 2, and 5 post-TBI.

SETTING

Inpatient rehabilitation centers with telephone follow-up.

PARTICIPANTS

Individuals enrolled in the TBIMS-NDB since 2001, aged 18-59, with employment data at 2 or more follow-up interviews at years 1, 2, and 5 (N=5683).

INTERVENTIONS

Not applicable.

MAIN OUTCOME MEASURE

Employment stability, categorized using post-TBI employment data as no paid employment (53.25%), stably (27.20%), delayed (10.24%), or unstably (9.31%) employed.

RESULTS

Multinomial regression analyses identified predictive factors of employment stability, including younger age, white race, less severe injuries, preinjury employment, higher annual earnings, male sex, higher education, transportation independence postinjury, and no anxiety or depression at 1 year post-TBI.

CONCLUSIONS

Employment stability serves as an important measure of productivity post-TBI. Psychosocial, clinical, environmental, and demographic factors predict employment stability post-TBI. Notable predictors include transportation independence as well as the presence of anxiety and depression at year 1 post-TBI as potentially modifiable intervention targets.

Cognition, Health-Related Quality of Life, and Depression Ten Years after Moderate to Severe Traumatic Brain Injury: A Prospective Cohort Study

The aim of this study was to evaluate cognitive function 10 years after moderate-severe traumatic brain injury (TBI) and to investigate the associations among cognitive function, depression, and health-related quality of life (HRQoL). In this prospective cohort study, with measurements at 3, 6, 12, 18, 24, 36, and 120 months post-TBI, patients 18-67 years of age (n = 113) with moderate-severe TBI were recruited. Main outcome measures were depression (Center for Epidemiologic Studies-Depression Scale [CES-D]), subjective cognitive functioning (Cognitive Failure Questionnaire [CFQ]), objective cognitive functioning, and HRQoL (Medical Outcomes Study 36-Item Short Form Health Survey [SF-36]). Fifty of the initial 113 patients completed the 10 year follow-up. Twenty percent showed symptoms of depression (CES-D ≥ 16). These patients had more psychiatric symptoms at hospital discharge (p = 0.048) and were more often referred to rehabilitation or nursing homes (p = 0.015) than non-depressed patients. Further, they also had significantly lower scores in six of the eight subdomains of the SF-36. The non-depressed patients had equivalent scores to those of the Dutch norm-population on all subdomains of the SF-36. Cognitive problems at hospital discharge were related with worse cognitive outcome 10 years post-TBI, but not with depression or HRQoL. Ten years after moderate-severe TBI, only weak associations (p < 0.05) between depression scores and two objective cognitive functioning scores were found. However, there were moderate associations (p < 0.01) among depression scores, HRQoL, and subjective cognitive functioning. Therefore, signaling and treatment of depressive symptoms after moderate-severe TBI may be of major importance for optimizing HRQoL in the long term. We did not find strong evidence for associations between depression and objective cognitive functioning in the long term post-TBI. Disease awareness and selective dropping out may play a role in long-term follow-up studies in moderate-severe TBI. More long-term research is needed in this field.

Genetic Variation in the Vesicular Monoamine Transporter: Preliminary Associations With Cognitive Outcomes After Severe Traumatic Brain Injury

INTRODUCTION

Traumatic brain injury (TBI) frequently results in impaired cognition, a function that can be modulated by monoaminergic signaling. Genetic variation among monoaminergic genes may affect post-TBI cognitive performance. The vesicular monoamine transporter-2 (VMAT2) gene may be a novel source of genetic variation important for cognitive outcomes post-TBI given VMAT2's role in monoaminergic neurotransmission.

OBJECTIVE

To evaluate associations between VMAT2 variability and cognitive outcomes post-TBI.

METHODS

We evaluated 136 white adults with severe TBI for variation in VMAT2 using a tagging single nucleotide polymorphism (tSNP) approach (rs363223, rs363226, rs363251, and rs363341). We show genetic variation interacts with assessed cognitive impairment (cognitive composite [Comp-Cog] T-scores) to influence functional cognition (functional independence measure cognitive [FIM-Cog] subscale] 6 and 12 months postinjury.

RESULTS

Multivariate analyses at 6 months postinjury showed rs363226 genotype was associated with Comp-Cog (P = .040) and interacted with Comp-Cog to influence functional cognition (P < .001). G-homozygotes had the largest cognitive impairment, and their cognitive impairment had the greatest adverse effect on functional cognition.

DISCUSSION

We provide the first evidence that genetic variation within VMAT2 is associated with cognitive outcomes after TBI. Further work is needed to validate this finding and elucidate mechanisms by which genetic variation affects monoaminergic signaling, mediating differences in cognitive outcomes.

The effects of post-traumatic depression on cognition, pain, fatigue, and headache after moderate-to-severe traumatic brain injury: a thematic review

BACKGROUND

Post-traumatic depression (PTD) is one of the most common secondary complications to develop after moderate-to-severe traumatic brain injury (TBI). However, it rarely manifests singularly, and often co-occurs with other common TBI impairments.

OBJECTIVE

The objective of this thematic review is to evaluate studies examining the relationships between PTD and cognition, fatigue, pain, and headache among individuals with moderate-to-severe TBI.

RESULTS

We reviewed 16 studies examining the relationship between PTD and cognition (five articles), fatigue (five articles), pain (four articles), and headache (two articles). Two studies failed to identify the significant associations between PTD and neuropsychological test performance, while one study found a positive association. Two other studies found that early PTD was associated with later executive dysfunction. Studies on fatigue suggest it is a cause, not consequence, of PTD. Individuals with PTD tended to report more pain than those without PTD. Studies examining relationships between PTD and post-traumatic headache were equivocal.

CONCLUSIONS

Studies evaluating the effects of PTD on common TBI impairments have yielded mixed results. Evidence suggests PTD precedes the development of executive dysfunction, and a strong link exists between fatigue and PTD, with fatigue preceding PTD. Future prospective studies evaluating PTD relationships to pain and headache are warranted to elucidate causality.

Safety and effectiveness of pharmacotherapy for depression in adults who have sustained a traumatic brain injury: a systematic review protocol

REVIEW OBJECTIVE/QUESTION

The objective of this systematic review is to synthesize the current evidence on the effectiveness and harms of pharmacotherapy in the management of depression in adults who have sustained a traumatic brain injury.

Managing Visitors During the Hospital Stay: The Experience of Family Caregivers of Patients With Traumatic Brain Injury

Family caregivers of patients with moderate-to-severe traumatic brain injury (TBI) regularly visit the patient during the hospital stay and are involved in their care. As impairments caused by the TBI often preclude the patient from stating preferences for visitors, family caregivers often make decisions about visitors on the patient's behalf during the hospital stay. However, limited literature investigates this process. The purpose of this study was to describe family caregivers' experience of visitors while the patient with moderate-to-severe TBI is hospitalized. Authors used grounded theory to conduct 24 interviews with 16 family caregivers. Findings showed family caregivers manage welcome and unwelcome visitors throughout the hospital stay to protect the patient's physical and emotional safety and to conserve their own energy. Staff had limited involvement in management of unwelcome visitors. These findings have practice implications for educating hospital staff about providing family nursing and assisting families to manage unwelcome visitors and about policy implications for improving hospital visiting policies.

What are the complications and emerging strategies for preventing depression following traumatic brain injury?

INTRODUCTION

Depression is a common and disabling complication of traumatic brain injury (TBI). The high rates of post-TBI depression (PTBID) make this condition an important candidate for selective preventive interventions. Areas covered: The authors recently reported on the efficacy of sertraline, a selective serotonin reuptake inhibitor (SSRI), for the prevention of new cases of depression in the first six months after TBI. The authors review this and other studies on preventive strategies in PTBID as ascertained from a PubMed and citation search. The potential complications and barriers to the implementation of pharmacological prevention in patients with TBI are also discussed. Expert commentary: The prevention of depression in patients with TBI has received little attention relative to other medical conditions. Future studies are needed to confirm the benefit of SSRIs and investigate other pharmacological and non-pharmacological interventions, including in special groups of patients at greater risk of developing PTBID.

Preliminary Associations Between Brain-Derived Neurotrophic Factor, Memory Impairment, Functional Cognition, and Depressive Symptoms Following Severe TBI

Background Traumatic brain injury (TBI) often leads to mood and cognitive complications, affecting functional recovery. Understanding neurobiological alterations common in post-TBI depression (PTD) and cognition may identify novel biomarkers for TBI complications. Brain-derived neurotrophic factor (BDNF) is a likely target based on evidence of reduced BDNF signaling in experimental TBI and depression models and its role in learning and memory. Objective To evaluate BDNF as a biomarker for PTD, cognitive impairment, and functional cognition in a prospective cohort with severe TBI. Methods Participants with TBI (n = 113) were evaluated for PTD (Patient Health Questionnaire-9 [PHQ-9]), cognitive impairment (cognitive composite score), and functional cognition (Functional Independence Measure-Cognition, FIM-Cog). BDNF levels were measured in cerebrospinal fluid and serum at 0 to 6 days postinjury and in serum at 6 and 12 months postinjury.

RESULTS

Serum BDNF was reduced after TBI versus controls at all time points. Acute serum BDNF positively correlated with memory composites (6 months: r = 0.43, P = .019, n = 30; 12 months: r = 0.53, P = .005, n = 26) and FIM-Memory scores (6 months: r = 0.35, P = .019, n = 45; 12 months: r = 0.38, P = .018, n = 38). Acute serum BDNF negatively correlated with 12-month PHQ-9 scores (r = -0.38; P = .044; n = 29). At 12 months, chronic serum BDNF tended to be lower in participants with PTD (P = .07) and correlated with PHQ-9 scores (r = -0.41; P = .019; n = 32). Conclusions Acute BDNF associations with memory recovery may implicate hippocampal damage/degeneration. Comparatively, BDNF associations with PTD status were not as strong as associations with PTD severity. Further investigation may delineate longitudinal BDNF patterns, and BDNF responsive treatments, reflecting mood and cognitive recovery following TBI.