The structure of the Hospital Anxiety and Depression Scale: Theoretical and methodological considerations.

The Hospital Anxiety and Depression Scale (HADS; Zigmond - Snaith, 1983) is widely used; however, its factor structure is unclear, with studies reporting differing unidimensional, two-factor and three-factor models. We aimed to address some key theoretical and methodological issues contributing to inconsistencies in HADS structures across samples. We reviewed existing HADS models and compared their fit using confirmatory factor analysis (CFA). We also investigated methodological effects by comparing factor structures derived from Rasch and Principal Components Analysis (PCA) methods, as well as effects of a negative wording factor. An Australian community-dwelling sample consisting of 189 females and 158 males aged 17-86 (M = 35.73, SD = 17.41) completed the 14-item HADS. The Rasch Analysis, PCA and CFA all supported the original two-factor structure. Although some three-factor models had good fit, they had unacceptable reliability. In the CFA, a hierarchical bifactor model with a general distress factor and uncorrelated depression and anxiety subscales produced the best fit, but the general factor was not unidimensional. The addition of a negative wording factor improved model fit. These findings highlight the effects of differing methodologies in producing inconsistent HADS factor structures across studies. Further replication of model fit across samples and refinement of the HADS items is warranted.

Growth Mixture Modeling of Depression Symptoms Following Traumatic Brain Injury.

Growth Mixture Modeling (GMM) was used to investigate the longitudinal trajectory of groups (classes) of depression symptoms, and how these groups were predicted by the covariates of age, sex, severity, and length of hospitalization following Traumatic Brain Injury (TBI) in a group of 1074 individuals (696 males, and 378 females) from the Royal Hobart Hospital, who sustained a TBI. The study began in late December 2003 and recruitment continued until early 2007. Ages ranged from 14 to 90 years, with a mean of 35.96 years (SD = 16.61). The study also examined the associations between the groups and causes of TBI. Symptoms of depression were assessed using the Hospital Anxiety and Depression Scale within 3 weeks of injury, and at 1, 3, 6, 12, and 24 months post-injury. The results revealed three groups: low, high, and delayed depression. In the low group depression scores remained below the clinical cut-off at all assessment points during the 24-months post-TBI, and in the high group, depression scores were above the clinical cut-off at all assessment points. The delayed group showed an increase in depression symptoms to 12 months after injury, followed by a return to initial assessment level during the following 12 months. Covariates were found to be differentially associated with the three groups. For example, relative to the low group, the high depression group was associated with more severe TBI, being female, and a shorter period of hospitalization. The delayed group also had a shorter period of hospitalization, were younger, and sustained less severe TBI. Our findings show considerable fluctuation of depression over time, and that a non-clinical level of depression at any one point in time does not necessarily mean that the person will continue to have non-clinical levels in the future. As we used GMM, we were able to show new findings and also bring clarity to contradictory past findings on depression and TBI. Consequently, we recommend the use of this approach in future studies in this area.

Risk factors for executive function difficulties in preschool and early school-age preterm children.

AIM: To investigate the relationship between executive functioning and social and perinatal risk factors in four- to five-year-old preterm children. METHODS: Using standardised measures of general intelligence and performance-based executive function (EF) tests prior to starting kindergarten, 141 children born preterm (<33 weeks of gestation) and 77 term comparison children were assessed. Parental and teacher reports of executive functioning were completed when the children commenced kindergarten. The preterm and the term comparison groups were compared on measures of intelligence and EFs using independent-groups t-tests, and multivariate regression analyses were performed to identify factors predictive of intelligence and executive functioning in the preterm group. RESULTS: The preterm group performed significantly more poorly than the comparison group on all intelligence and EF tests. The parental reports of the preterm and term comparison children's EF did not differ significantly, but the teachers reported elevated EF difficulties for the preterm group. Higher social risk, in particular lower educational level of the main caregiver, was the strongest predictor for the preterm children's intelligence and EF results. CONCLUSION: Social risk factors are strongly associated with impaired early EF outcomes in preterm children.

Is APOE ε4 associated with poorer cognitive outcome following traumatic brain injury? A meta-analysis.

OBJECTIVE: Cognitive impairment is a common sequelae of traumatic brain injury (TBI); however, predicting who will experience poorer outcomes remains challenging. A potential risk factor that has gained attention is the APOE gene, with the ε4 allele hypothesized to have a detrimental effect on post-TBI cognitive outcome. The aim of this meta-analysis was to evaluate the effect of APOE ε4 both in terms of general cognitive function and within specific domains known to be prone to impairment following TBI (executive function, working memory, verbal memory and visual memory). METHOD: A literature search was undertaken in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-analysis (PRISMA), resulting in the inclusion of 10 studies (ε4-carriers n = 143, noncarriers n = 510). Neuropsychological tasks were identified, and Cohen's d was calculated and pooled. Meta-analyses were conducted on general cognitive functioning and for the specific cognitive domains of interest. RESULTS: No significant differences were found between APOE ε4-carriers or noncarriers, either in general cognitive function or in the cognitive domains of executive function, working memory, verbal memory, or visual memory. CONCLUSIONS: This meta-analysis indicates that APOE ε4 does not have a detrimental effect on cognitive performance following TBI. We propose that the relationship between APOE and cognitive function following TBI is complex, and a more-nuanced exploration of APOE genotypes is needed. (PsycINFO Database Record

Exploring the effect of the apolipoprotein E (APOE) gene on executive function, working memory, and processing speed during the early recovery period following traumatic brain injury.

INTRODUCTION: There is evidence that the e4 allele of the apolipoprotein E (APOE) gene is detrimental to cognitive function, but results from traumatic brain injury (TBI) populations are mixed. A possible explanation is that APOEe2 carriers have routinely been incorporated into APOEe4 and non-e4 groups, despite APOEe2 being proposed to have an ameliorative effect. Our primary aim was to investigate the influence of APOEe4 on cognitive impairment during early recovery following TBI, excluding the potential confound of APOEe2 possession. A secondary objective was to explore whether APOEe4 displays more pronounced effects in moderate to severe TBI and to consider the potential postinjury protective influence of the APOEe2 allele. METHOD: Participants who recently sustained a TBI (posttraumatic amnesia > 5 minutes) were assessed on measures of information processing speed, executive function, and working memory upon remission of posttraumatic amnesia. APOE genotype was determined by buccal saliva DNA extraction (APOEe4 n = 37, APOEe3 n = 92, APOEe2 n = 13). RESULTS: Stepwise multiple regressions were performed to compare APOEe4 carriers to APOEe3 homozygotes, with injury severity, age, and estimated premorbid IQ included in the first step. This model was found to significantly predict performance on all tasks, accounting for 17.3-24.3% of the variance. When APOEe4 status was added for the second step, there were no significant changes on any tasks (additional variance <1%). The effect of APOEe4 in moderate to severe TBI and the effect of APOEe2 were explored by analysis of covariance (ANCOVA), with no significant effects revealed. CONCLUSIONS: It is unlikely that APOE genotype influences cognitive function in the initial recovery period following TBI, regardless of injury severity. However, a more nuanced and long-term exploration of the effect of APOE genotype in the TBI population is warranted.

Service utilisation in a public post-acute rehabilitation unit following traumatic brain injury.

Traumatic brain injury (TBI) causes disability in a proportion of survivors across the spectrum of injury severity. Previous research suggests physical changes are the primary focus of rehabilitation, although cognitive, emotional and behavioural difficulties cause greater concern in the long-term. There is little information about services accessed by those with mild injuries, who often have no physical disabilities. This study investigated factors determining service utilisation in a population-based sample which included 52% mild injuries (PTA ≤ 24 hours). Chi-squares and t-tests were used to examine the impact of demographic, clinical, psychological and physical variables on referral of 175 TBI patients to clinical disciplines in a public, community-based rehabilitation facility in Hobart, Tasmania. Increased service intensity (total disciplines referred to), was associated with greater injury severity (p = .006) and previous TBI (p = .041). Less traditional rehabilitation services (nursing, psychology) received more referrals than traditional disciplines (physiotherapy, occupational therapy, social work). Referral to physiotherapy and occupational therapy was associated with greater injury severity, functional dependence, hospitalisation and older age. Referral to nursing, psychology and social work was associated with more post-concussion symptoms, younger age, anxiety, depression and assault-related injury. The large number of referrals to psychology strengthens the case for including it as a core rehabilitation discipline.

Impaired National Adult Reading Test (NART) performance in traumatic brain injury.

Some research suggests the National Adult Reading Test (NART) may be impaired by traumatic brain injury (TBI). To investigate this, a prospective, longitudinal study included 214 Australian TBI participants given the NART within 1 month post-injury, and at 6 and 12 months. TBI severity, age, education, sex, and mood (HADS) were examined, and significant improvement in NART- estimated full-scale IQ (FSIQ) was noted over time (p < .001). A three-way interaction of time, severity, and age showed younger and middle-aged mild TBI sub-groups improved significantly between 1 and 6 months post-injury, and the older sub-group between 6 and 12 months. In severe TBI, significant NART-estimated FSIQ improvement was noted only for the middle-aged and only between 6 and 12 months post-TBI. NART administration soon after TBI underestimated premorbid IQ, with a complex relationship between time post-injury, severity, and age. Participants with a longer education had higher NART FSIQs, although those with less education gained more IQ points between initial and 6 months assessments suggesting higher initial NART impairment. Regression equations predicted NART FSIQ at 6 (R = 0.813) and 12 months post-trauma (R = 0.792-0.845), their effectiveness being confirmed via cross-validation. No significant relationships were noted between NART-estimated FSIQ and mood variables, or evidence of significant gains in estimated FSIQ between 12 and 24 months post-injury.

The figure copy and recall test of the Adult Memory and Information Processing Battery: inter-rater reliability.

OBJECTIVE: Examined inter-rater reliability of the scoring of the Figure Copy and Recall subtest of the Adult Memory and Information Processing Battery (AMIPB; Coughlan & Hollows, 1985). METHOD: Figure Copy and Recall tests of 56 individuals referred for neuropsychological assessment were independently scored by three experienced neuropsychologists and the scores correlated. Detailed analysis of reasons for scoring discrepancies was carried out. RESULTS: Raters scores were highly correlated in relation to both forms of the tests. The major source of discrepancy was errors in accuracy. CONCLUSIONS: Results indicate that the AMIPB manual instructions are sufficiently detailed to obtain good inter-rater reliability when the raters are experienced clinicians. Further research using trainees or assistant psychologists is suggested.

NART prediction and impairment in neurological patients.

Crawford, Allan, Cochrane, and Parker (1990) used demographic variables in a multiple regression equation to predict NART error scores in a general population sample. The present study examined the applicability of Crawford's equation to neurological patients. Using this equation and the authors' suggestion that NART performance can be impaired in neurological patients, the data were also examined in participants with diffuse cortical damage. Participants (n = 175) were patients referred for clinical neuropsychological evaluation in north-east England. The findings confirmed the usefulness of Crawford's equation: Participants showing significantly higher obtained than predicted NART error scores (identified using Crawford's equation), were categorised as NART-impaired. Analyses of NART-impaired and NART-unimpaired patient subgroups showing diffuse cortical damage indicated the former had a significantly higher mean NART error score and mean discrepancy between NART-predicted and observed IQs. However, a significantly lower mean verbal (VIQ) IQ score was also noted in the NART-impaired participants, suggesting that the risk of an impaired NART performance is greater in a diffusely damaged patient with a lower premorbid VIQ.