Attachment and Clinical Outcomes Among Treatment-Seeking Adults With Persistent Symptoms After Mild Traumatic Brain Injury
Abstract
Objective:
Interpersonal attachment influences the development and course of disease. Overreliance on insecure attachment strategies may increase risk for poor disease outcomes. This study aimed to investigate largely unexplored relationships between attachment strategies and clinical outcomes among adults with persistent symptoms after mild traumatic brain injury (mTBI).
Methods:
Participants with persistent symptoms after mTBI (N=83) completed measures assessing dimensions of insecure attachment (Relationship Scales Questionnaire [RSQ]), persistent symptoms (Rivermead Post-Concussion Symptoms Questionnaire), depression (Patient Health Questionnaire–9), anxiety (Generalized Anxiety Disorder–7), and health-related quality of life (HRQOL) (Quality of Life After Brain Injury—Overall Scale). Questionnaires were administered at clinic intake (mean=18.1 weeks postinjury) and again 3–4 months later (mean=32.2 weeks postinjury), except the RSQ, which was administered only in the follow-up assessment. Treatment response for each outcome was calculated as the difference between scores at clinic intake and follow-up. Generalized linear models were fitted for each clinical outcome, with RSQ variables as predictors.
Results:
Higher attachment anxiety was associated with greater persistent symptom severity, greater depression and anxiety symptoms, and worse HRQOL at follow-up. Higher attachment anxiety was also associated with less improvement in depression and HRQOL over time. In contrast, attachment avoidance was unrelated to any of the clinical outcomes.
Conclusions:
Attachment anxiety, the fear that a significant other will not be available in stressful circumstances, may be a particularly important social factor associated with health among adults with persistent symptoms after mTBI. Greater consideration of the attachment system is warranted in mTBI care and research.
Up to one-third of people who sustain a mild traumatic brain injury (mTBI) develop persistent symptoms, such as fatigue, headaches, and memory or concentration problems (1–5). Persistent symptoms after mTBI are not likely caused by mTBI alone (6). Risk factors for persistent symptoms include preinjury or comorbid psychiatric disorders as well as maladaptive psychological coping (7–11). Interpersonal factors, such as the quantity and quality of relationships and the positive and negative aspects of these relationships, may also influence mTBI outcomes (11, 12).
Attachment theory suggests that early experiences with caregivers predict how people feel and interact in close relationships across the lifespan (13–15). Insecure attachment is characterized by high attachment anxiety (i.e., discomfort separating from an attachment figure), high attachment avoidance (i.e., discomfort being too dependent on that figure), or both. Interpersonal challenges may arise throughout the lifespan because of insecure attachment, especially in stressful or threatening circumstances (16). After mTBI, individuals with high attachment anxiety may be overly reliant on others and experience emotional distress when their attachment needs cannot be met. Individuals with high attachment avoidance may become increasingly self-reliant, preventing them from receiving the support and care they need as they recover.
Although mTBI is often experienced as distressing and threatening (17), it has been scarcely studied as a potential trigger of insecure attachment strategies. Only one prior study has investigated the relationship between persistent symptoms and attachment after mTBI, through a cross-sectional survey (N=973) of Danish people 3–9 months after mTBI (18). The authors found that attachment anxiety was associated with persistent symptom severity among people with high attachment avoidance and that attachment avoidance was associated with persistent symptom severity, regardless of attachment anxiety levels. Severity of persistent symptoms was highest among participants with high scores on both attachment dimensions (i.e., paradoxically, being afraid of both dependence and autonomy) (18). Limitations of this study included a low survey response rate (39%), restricted age range (ages 15–30), and consideration of a single clinical outcome—reported persistent symptoms (18).
Attachment strategies have been studied in relation to health conditions that share clinical features with persistent symptoms after mTBI. In individuals with functional neurological disorder, higher scores for both insecure attachment dimensions were associated with greater symptom severity, depression, and anxiety, whereas secure attachment style was associated with better symptom improvements after treatment (19, 20). In individuals with chronic pain, a condition with clinical features that resemble persistent symptoms after mTBI (21), both insecure attachment strategies were associated with the presence and severity of chronic pain and with worse depression (22–24). In summary, evidence from studies of related health conditions suggests that attachment may possibly be related not only to persistent symptoms after mTBI but also to a range of other outcomes, including psychological functioning, health-related quality of life (HRQOL), and treatment response among people with mTBI. The aim of the present study was to directly test this hypothesis.
Based on attachment theory and prior research, we hypothesized that insecure attachment strategies (higher level of attachment anxiety or avoidance) would be associated with more severe persistent symptoms, worse HRQOL, and worse psychological functioning (i.e., higher levels of depression and anxiety) after mTBI. Moreover, we hypothesized that insecure attachment strategies would be associated with worse treatment responses (i.e., smaller reductions in persistent symptoms and mental health symptoms and less improvement in HRQOL over a preceding course of treatment).
Methods
Sample and Procedure
Adults with mTBI (N=91) were recruited from two outpatient mTBI clinics in British Columbia, Canada, between April 2019 and February 2020. Eighty-four individuals in the sample completed the outcome assessment. Questionnaires were administered at clinic intake (mean=18.1 weeks postinjury) and again 3–4 months later (mean=32.2 weeks postinjury)—except for the Relationship Scales Questionnaire (RSQ), which was administered only in the follow-up assessment—under the empirically supported assumption that attachment styles are stable through adulthood (14). One participant was excluded from the analysis because of missing data, leaving 83 participants.
This secondary analysis (25) included data from participants who were part of a feasibility randomized controlled trial of two behavioral interventions (N=73) (25) as well as data from participants who were excluded from this parent study because they did not exhibit maladaptive coping but were still invited for the follow-up assessment (N=10). For the parent study, research assistants used a structured interview to confirm a diagnosis of mTBI that met the World Health Organization Neurotrauma Task Force definition (26). This diagnosis requires a plausible mechanism of head trauma by external force with at least one clinical sign of altered mental status, including a Glasgow Coma Scale score of 13 or 14, loss of consciousness (up to 30 minutes), and posttraumatic amnesia (up to 24 hours). All participants had unrestricted access to usual care. Their self-reported treatment utilization is shown in Table 1. Of the 73 participants who received a study intervention, 37 received graded exposure therapy and 36 received training on operant conditioning–based pacing strategies. Both study interventions were codelivered by psychology and occupational therapy providers, as described elsewhere (25). Attachment styles and interpersonal relationships were not a focus of either experimental intervention.
| Characteristic | N | % |
|---|---|---|
| Gender | ||
| Female | 54 | 65 |
| Male | 29 | 35 |
| Age (M±SD years) | 41.3±12.0 | |
| Race-ethnicity | ||
| White | 61 | 74 |
| Asian | 15 | 18 |
| Other | 7 | 8 |
| Education | ||
| High school or less | 5 | 6 |
| Some college but no degree | 14 | 17 |
| Technical degree, diploma, or associate degree | 18 | 22 |
| Bachelor’s degree | 24 | 29 |
| Master’s degree | 14 | 17 |
| Professional school degree or doctorate | 8 | 10 |
| Mechanism of injury | ||
| Motor vehicle accident | 30 | 36 |
| Fall | 14 | 17 |
| Assault | 22 | 27 |
| Other | 17 | 21 |
| Loss of consciousness with index injury | ||
| Yes | 12 | 15 |
| No | 71 | 86 |
| Time since injury at clinic intake (M±SD weeks) | 18.1±10.8 | |
| Time since injury at follow-up assessment (M±SD weeks) | 32.2±11.8 | |
| Self-reported treatment utilization from intake to follow-up | ||
| Emergency department | 6 | 7 |
| General practitioner or family physician | 69 | 83 |
| Physician specialist | 24 | 29 |
| Physiotherapy | 55 | 66 |
| Occupational therapy | 23 | 28 |
| Psychological therapy or counselling | 33 | 40 |
| Massage therapy | 43 | 52 |
| Chiropractic treatment | 19 | 23 |
| Acupuncture | 19 | 23 |
| Other | 15 | 18 |
| RSQ scorea | ||
| Attachment anxiety (M±SD) | 2.4±1.1 | |
| Attachment avoidance (M±SD) | 2.1±0.8 | |
| RPQ scoreb | ||
| Intake (M±SD) | 33.5±14.6 | |
| Follow-up (M±SD) | 22.9±14.7 | |
| QOLIBRI-OS scorec | ||
| Intake (M±SD) | 27.7±17.3 | |
| Follow-up (M±SD) | 47.2±24.7 | |
| PHQ-9 scored | ||
| Intake (M±SD) | 12.4±5.9 | |
| Follow-up (M±SD) | 7.8±5.9 | |
| GAD-7 scoree | ||
| Intake (M±SD) | 9.0±5.1 | |
| Follow-up (M±SD) | 5.8±4.9 | |
TABLE 1. Demographic characteristics, injury information, and questionnaire data for individuals with persistent symptoms after mild traumatic brain injury (mTBI) (N=83)
Measures
Attachment.
Attachment was assessed with the self-report RSQ (27). On a 5-point scale, participants were instructed to “rate the extent to which you believe each statement best describes your feelings about close relationships” for all 30 statements. The scale was designed to measure four dimensions of attachment strategies (i.e., secure, dismissing, preoccupied, and fearful). However, attachment styles are better captured with the anxiety and avoidance dimensions (28), which can be translated into the original four attachment strategies (i.e., secure, low on both dimensions; fearful, high on both dimensions; preoccupied, high on anxiety and low on avoidance; dismissing, high on avoidance and low on anxiety). The two-dimensional model has more favorable psychometric properties than the four-factor model of the RSQ (29, 30). Similarly, exploratory factor analysis in the present sample suggested superior fit for the two-dimensional model (comparative fit index=0.96) with attachment anxiety measured with items 9, 11, 16, 21, 23, 25, and 28 and attachment avoidance measured with items 6, 13, 20, 24, and 29 (29). Both subscales of the RSQ showed adequate internal consistency in the present sample (attachment anxiety: α=0.92, 95% confidence interval [CI]=0.88 to 0.95; attachment avoidance: α=0.79, 95% CI=0.72 to 0.84).
Persistent symptoms after mTBI.
Persistent symptoms after mTBI were assessed with the 16-item Rivermead Post-Concussion Symptoms Questionnaire (RPQ) (31). Participants were asked to compare symptoms experienced over the past 24 hours with preinjury experiences on a scale ranging from 0, never experienced, to 4, severe symptoms. Items rated 0 or 1 (no worse than before the injury) were scored as zero. All item scores were summed to create a total score ranging from 0 to 64. Examples of RPQ symptoms include headaches, sleep disturbance, fatigue, and poor concentration (31). Evidence from previous studies suggests that the RPQ has high construct validity and good internal and test-retest reliability (31, 32).
Depression symptoms.
The nine-item Patient Health Questionnaire (PHQ-9) (33) was used to measure the severity of depression symptoms (e.g., “feeling down, depressed, or hopeless”) within the past 2 weeks. Items were rated on a 4-point scale ranging from 0, not at all, to 3, nearly every day. Higher scores indicate greater severity, with a maximum total score of 27. The PHQ-9 is a reliable and valid measure of depression (33).
Anxiety symptoms.
Anxiety was assessed with the seven-item Generalized Anxiety Disorder scale (GAD-7) (34). This questionnaire was used to assess experiences with symptoms of anxiety (e.g., “feeling anxious, nervous, or on edge”) over the past two weeks. Items were rated from 0, not at all, to 3, nearly every day. Higher scores are associated with greater levels of anxiety, with a maximum total score of 21. The GAD-7 has good internal consistency, test-retest reliability, and validity (34).
HRQOL.
HRQOL was assessed with the Quality of Life After Brain Injury—Overall Scale (QOLIBRI-OS) (35). The QOLIBRI-OS is a six-item self-report measure that captures overall satisfaction with facets of life (e.g., physical condition, cognition, emotions, function in daily life) after injury. Items were scored from 0, not at all, to 5, very, and the sum of all items was converted arithmetically to a percentage scale ranging from 0 to 100, with higher scores indicating greater satisfaction (35). The QOLIBRI-OS has good internal consistency, reliability, and construct validity (35).
The parent study also included standardized assessments of cognition (National Institutes of Health Toolbox Cognition Battery), vestibular-oculomotor function (Vestibular/Ocular Motor Screening Test), and exercise tolerance (Buffalo Concussion Bike Test [36]). These measures were not analyzed here because they were administered only in the intake assessment and not during the follow-up assessment (which is when the RSQ was administered).
Statistical Analysis
Descriptive statistics were used to characterize the demographic and clinical characteristics of the study sample. The PHQ-9 and GAD-7 scores were positively skewed, so we fitted generalized linear models for all outcome measures, which can accommodate nonnormally distributed response variables. Treatment response for each outcome was calculated as the difference between scores obtained at clinic intake and follow-up. Each model included an outcome measure at follow-up (or a treatment response) as the response variable and attachment anxiety, attachment avoidance, and the interaction term between the two dimensions as explanatory factors. For depression and anxiety symptoms, the gamma response family with a log link function best fit the data, as indicated by the lowest Akaike information criterion value. For HRQOL, persistent symptoms after mTBI, and treatment response ratings, a Gaussian response family with an identity link function best fit the data. To control for multicollinearity, we mean-centered the interaction term between two attachment dimensions. Furthermore, we included gender and group conditions from the randomized control trial as covariates in a second step for each model to control for potential confounders. Wald tests were conducted to test the hypotheses within each generalized linear model. All analyses were conducted with SPSS, version 28.0, and R.
Results
Table 1 displays the sample characteristics and descriptive statistics for the predictor and outcome measures. Generalized linear modeling results are presented in Table 2. Higher attachment anxiety was associated with greater persistent symptom severity (B=3.65, 95% CI=0.66 to 6.64, p=0.017), greater symptoms of depression and anxiety (B=0.36, 95% CI=0.11 to 0.61, p=0.004; B=0.38, 95% CI=0.09 to 0.68, p=0.011), and worse HRQOL (B=−9.49, 95% CI=−14.22 to −4.75, p<0.001) at follow-up. Higher attachment anxiety was also associated with less improvement in depression (B=−1.12, 95% CI=−2.30 to −0.09, p=0.033) and HRQOL (B=−6.37, 95% CI=−10.27 to −2.47, p=0.001) from clinic intake to follow-up. In contrast, attachment avoidance was not significantly related to any of the clinical outcomes. Interaction effects between attachment anxiety and avoidance were nonsignificant, except for HRQOL (B=5.50, 95% CI=0.98 to 10.02, p=0.017), in which high attachment avoidance was associated with lower HRQOL among participants with low attachment anxiety (Figure 1). No significant changes were found in the results after we included gender and group conditions as covariates.
| B | SE | Wald 95% CI | Wald χ2 | p | Likelihood ratio χ2 | p | |
|---|---|---|---|---|---|---|---|
| Model 1: persistent symptoms | 9.76 | 0.021* | |||||
| Attachment anxiety | 3.65 | 1.52 | 0.66, 6.64 | 5.73 | 0.017* | ||
| Attachment avoidance | 2.49 | 1.99 | −1.40, 6.39 | 1.57 | 0.210 | ||
| Anxiety × avoidance | −1.30 | 1.46 | −4.15, 1.56 | 0.79 | 0.373 | ||
| Model 2: persistent symptoms treatment response | 2.39 | 0.496 | |||||
| Attachment anxiety | −1.00 | 1.40 | −3.75, 1.74 | 0.51 | 0.474 | ||
| Attachment avoidance | −1.79 | 1.82 | −5.37, 1.79 | 0.96 | 0.326 | ||
| Anxiety × avoidance | −0.17 | 1.34 | −2.79, 2.45 | 0.02 | 0.898 | ||
| Model 3: depression | 9.79 | 0.020* | |||||
| Attachment anxiety | 0.36 | 0.13 | 0.11, 0.61 | 8.12 | 0.004** | ||
| Attachment avoidance | 0.09 | 0.16 | −0.22, 0.40 | 0.32 | 0.569 | ||
| Anxiety × avoidance | −0.12 | 0.11 | −0.34, 0.10 | 1.09 | 0.296 | ||
| Model 4: depression treatment response | 5.71 | 0.127 | |||||
| Attachment anxiety | −1.12 | 0.56 | −2.30, −0.09 | 7.13 | 0.033* | ||
| Attachment avoidance | 1.33 | 0.74 | −0.13, 2.79 | 4.52 | 0.073 | ||
| Anxiety × avoidance | −0.03 | 0.54 | −1.09, 1.02 | 3.30 | 0.951 | ||
| Model 5: anxiety | 7.91 | 0.048* | |||||
| Attachment anxiety | 0.38 | 0.15 | 0.09, 0.68 | 6.53 | 0.011* | ||
| Attachment avoidance | 0.08 | 0.18 | −2.78, 0.44 | 0.19 | 0.659 | ||
| Anxiety × avoidance | −0.09 | 0.13 | −0.35, 0.17 | 0.48 | 0.488 | ||
| Model 6: anxiety treatment response | 2.82 | 0.422 | |||||
| Attachment anxiety | −0.47 | 0.43 | −1.32, 0.38 | 1.18 | 0.277 | ||
| Attachment avoidance | 0.89 | 0.56 | −0.22, 1.99 | 2.49 | 0.115 | ||
| Anxiety × avoidance | −0.06 | 0.41 | −0.86, 0.75 | 0.02 | 0.894 | ||
| Model 7: quality of life | 19.97 | 0.001 *** | |||||
| Attachment anxiety | −9.49 | 2.42 | −14.22, −4.75 | 15.42 | <0.001*** | ||
| Attachment avoidance | −2.88 | 3.15 | −9.06, 3.28 | 0.84 | 0.359 | ||
| Anxiety × avoidance | 5.50 | 2.31 | 0.98, 10.02 | 5.68 | 0.017* | ||
| Model 8: quality of life treatment response | 11.97 | 0.007** | |||||
| Attachment anxiety | −6.37 | 1.99 | −10.27, −2.47 | 10.24 | 0.001** | ||
| Attachment avoidance | −0.18 | 2.59 | −5.27, 4.90 | 0.01 | 0.867 | ||
| Anxiety × avoidance | 3.51 | 1.90 | −0.22, 7.24 | 3.40 | 0.065 |
TABLE 2. Generalized linear models for relationship between attachment dimensions and clinical outcomes among individuals with persistent symptoms after mTBI (N=83)
FIGURE 1. Interaction between attachment anxiety and attachment avoidance for health-related quality of life (HRQOL)a
aHigh and low anxiety correspond to mean attachment anxiety scores of the upper and lower 50th percentile of participants, respectively. High and low avoidance correspond to mean attachment avoidance score of the upper and lower 50th percentile of participants, respectively.
Discussion
The current study investigated the relationship between attachment and a range of clinical outcomes among treatment-seeking adults with mTBI. We hypothesized that participants with insecure attachment strategies (higher level of attachment anxiety, attachment avoidance, or both) would report more severe persistent symptoms, lower HRQOL, lower psychological functioning, and worse treatment outcomes (i.e., less improvement on all outcome measures over the preceding months) after mTBI. Our findings partially supported these hypotheses. We found significant associations between attachment anxiety and persistent symptoms, depression and anxiety symptoms, and HRQOL 4–5 months after mTBI. Higher attachment anxiety was also associated with less improvement in depression and HRQOL during the active treatment phase, from clinic intake to follow-up. Attachment avoidance was largely unrelated to clinical outcomes from mTBI in this study. The one exception was that high attachment avoidance was associated with lower HRQOL among participants with low attachment anxiety, whereas those with high attachment anxiety had lower HRQOL regardless of attachment avoidance levels. Our results suggest that attachment anxiety, the fear that a significant other will not be available in stressful circumstances, has a greater association with clinical outcomes and recovery among adults with persistent symptoms after mTBI than does attachment avoidance.
Theoretical frameworks have proposed that insecure attachment leads to interpersonal dysfunction and poor health (12, 22), but the present study design did not allow us to draw causal conclusions. The mechanisms through which insecure attachment might interfere with recovery from mTBI were also not clear. Hyperactivation of the attachment system among individuals with high attachment anxiety may be associated with affect regulation difficulties (22, 37). Psychological distress can amplify the severity of persistent symptoms, in part because physical symptoms of sympathetic nervous arousal overlap with persistent symptoms and can be misattributed to mTBI (38, 39). In other words, psychological distress may be both an outcome of insecure attachment and a mediator through which insecure attachment worsens persistent symptoms after mTBI. Being overly reliant on others may also prevent opportunities for people with mTBI to resume their preinjury responsibilities and experience success, updating their beliefs about their capabilities as they recover. In contrast, attachment avoidance, the discomfort of being too dependent on others, may manifest as an underreporting of symptoms (22). The capacity of attachment avoidance to provoke the repetitive cycle of enduring activity-related exacerbations of persistent symptoms and then “crashing” with prolonged rest may disrupt daily functioning and HRQOL after mTBI (9). Further research is needed to evaluate this tentative model.
Our findings add to the literature linking insecure attachment to adverse health outcomes (22, 40–43) by demonstrating this association in the context of mTBI. Our findings add nuance to the only prior study of attachment in the context of mTBI (18), which similarly found that insecure attachment was associated with persistent symptoms after mTBI, but the pattern and relative strength of attachment anxiety and avoidance dimensions differed. That study was large but cross-sectional, included only participants ages 15–30, and considered only severity of persistent symptoms (18). The present study extends Tuborgh et al. (18) by assessing a range of different clinical outcomes, including persistent symptoms, depression, anxiety, and HRQOL as well as changes in these measures during the active treatment phase after mTBI across adulthood. Compared with participants in the Tuborgh et al. study, our participants were older, more symptomatic, and seeking specialty outpatient treatment for mTBI. These sampling differences may have contributed to the subtle between-study discrepancies.
This study had several limitations. First, although attachment strategies are quite stable across the lifespan (14), it remains possible that the experience of mTBI with protracted recovery increased insecure attachment. For example, a recent study suggested that greater mTBI symptoms were related to decreases in relationship satisfaction 1 month postinjury (44). We tested this assumption in exploratory analyses and found that participants with greater injury severity (indexed by the presence of witnessed loss of consciousness) reported significantly higher attachment avoidance (M±SD=2.60±0.87) than those with no loss of consciousness (M±SD=2.03±0.79; t=2.27, df=81, p=0.026, d=0.71). Associations of the presence or absence of loss of consciousness with attachment anxiety and persistent symptom severity were not statistically significant, but the effect sizes were not trivial. These post-hoc analyses suggest that the attachment system, particularly avoidance strategies, might be influenced by mTBI. Thus, it is tenuous to assume that the RSQ measured only “premorbid” attachment strategies in this study. Second, we measured attachment strategies with a self-report measure (RSQ) that queries about relationships in general. Attachment is dyadic and may be specific to relationships with certain people (45). Evidence of weak correlations between self-report attachment strategies and dyadic assessment of attachment (i.e., narrative interviews or coding of observations) has also been reported. Third, self-reported outcome measures such as the RPQ are clinically meaningful but cannot provide a complete picture of recovery from mTBI. A multimodal outcome assessment that included objective measures of cognition and vestibular-oculomotor function, for example, would have been preferable. Fourth, we had a relatively small sample size that may have resulted in insufficient power to detect additional interaction effects and associations with changes over time. Fifth, our participants may have had more clinical care than is typical at other mTBI clinics. This discrepancy may influence the generalizability of the results, especially our analyses involving change during the study observation period. However, the usual care and experimental interventions our participants received are not outside the wide range of offerings at other mTBI clinics with regard to the number and types of providers involved as well as the content and aims of the intervention (46–48). Despite these limitations, the current study was the first to assess the relationships between attachment strategies and a comprehensive set of clinical outcomes (i.e., persistent symptoms, depression and anxiety symptoms, and HRQOL) after mTBI and over a period of outpatient treatment.
Conclusions
Overall, our findings suggest that attachment strategies in current relationships may buffer or exacerbate stress after mTBI and that having persistent symptoms may strain relationships and attachment strategies. Greater consideration of the attachment system may improve understanding and management of persistent symptoms after mTBI (12). Future studies should use interview-based or observational measures of attachment and consider repeated measures of attachment strategies to assess their stability. Future research is needed to disentangle the directionality of the relationship between attachment strategies and clinical outcomes after mTBI. Longitudinal assessment of attachment strategies and analyses of individual trajectories might reveal unique patterns (attachment strategies contributing to persistent symptoms, persistent symptoms influencing attachment strategies, or both) for different patients. Possible associations between attachment strategies and other outcomes, such as health care utilization, should also be investigated in a larger sample.
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