Karen A. Sullivan

An Examination of the Base Rates of Post-Concussion Symptoms: The Influence of Demographics and Depression

Post-concussion syndrome (PCS) is a controversial constellation of cognitive, emotional, and physical symptoms that some patients experience following a mild traumatic brain injury or concussion. PCS-like symptoms are commonly found in individuals with depression, pain, and stress, as well as healthy individuals. This study investigated the base rate of PCS symptoms in a healthy sample of 96 participants and examined the relationship between these symptoms, depression, and sample demographics. PCS symptoms were assessed using the British-Columbia Post-Concussion Symptom Inventory. Depression was measured using the Beck Depression Inventory II. Results demonstrated that: The base rate of PCS was very high; there was a strong positive relationship between depression and PCS; and demographic characteristics were not related to PCS in this sample. These findings are broadly consistent with literature suggesting a significant role for non-neurological factors in the expression of PCS symptomatology. This study adds to the growing body of literature that calls for caution in the clinical interpretation of results from PCS symptom inventories.

Alexithymia, craving and attachment in a heavy drinking population

Up to fifty per cent of individuals with Alcohol use disorders (AUD) also have alexithymia a personality construct hypothesized to be related to attachment difficulties. The relationship between alexithymia, craving, anxious attachment and alcohol-dependence severity was examined in 254 patients participating in a Cognitive-Behavioral Therapy (CBT) program for alcohol-dependence. Participants completed the Toronto Alexithymia Scale (TAS-20), the Obsessive Compulsive Drinking Scale (OCDS), the Revised Adult Attachment Anxiety Subscale (RAAS-Anxiety) and the Alcohol Use Disorder Identification Test (AUDIT). MANOVA indicated that individuals with alexithymia reported significantly higher levels of total OCDS, obsessive thoughts about alcohol, and compulsive drinking urges and behavior, compared to the non-alexithymic group. Regression analyses found that anxious attachment partially mediated the relationship between alexithymia and craving. Anxious attachment may be a potential treatment target to reduce alcohol consumption in those with alcohol-dependence and alexithymia.

The Relationship Between Personality Characteristics and Postconcussion Symptoms in a Nonclinical Sample

Postconcussion symptoms are relatively common in the acute recovery period following mild traumatic brain injury. However, for a small subset of patients, self reported postconcussion symptoms continue long after injury. Many factors have been proposed to account for the presence of persistent postconcussion symptoms. The influence of personality traits has been proposed as one explanation. The purpose of this study was to examine the relation between postconcussion-like symptom reporting and personality traits in a sample of 96 healthy participants. Participants completed the British Columbia Postconcussion Symptom Inventory and the Millon Clinical Multiaxial Inventory III (MCMI-III). There was a strong positive relation between the majority of MCMI-III scales and postconcussion-like symptom reporting. Approximately half of the sample met the International Classification of Diseases-10 Criterion C symptoms for Postconcussional Syndrome. Compared with those participants who did not meet this criterion, the PCS group had significant elevations on the negativistic, depression, major depression, dysthymia, anxiety, dependent, sadistic, somatic, and borderline scales of the MCMI-III. These findings support the hypothesis that personality traits can play a contributing role in self reported postconcussion symptoms.

Neuropsychological assessment of mental capacity

The assessment of mental capacity to assist legal determinations of competency is potentially a growth area for neuropsychology, although to date neuropsychologists have published relatively little in this area. In this paper a systematic review of methods used to assess capacity is presented, including coverage of specialized tests and interviews used for this purpose. A neuropsychological model for conducting capacity assessments is proposed. This model involves comprehensive assessment of a wide range of cognitive abilities as well as assessment of specific skills and knowledge related to the type of capacity being assessed. The purpose of proposing this model is to stimulate further discussion and debate about the contribution neuropsychologists might make in this area.

Should a diagnosis of Alzheimer's disease be disclosed?

There is evidence that some health practitioners may be reluctant to disclose a diagnosis of Alzheimers disease (AD) to patients. However, this reluctance towards disclosure may not be in accordance with patient expectation. This study examined the attitudes of 100 undergraduate psychology students towards disclosure practices in relation to AD, before and after exposure to AD education. After AD education, 93% of participants indicated a desire to be informed of a diagnosis of AD, and 95% of participants were in favour of telling a close relative a diagnosis of AD. Results are discussed in terms of the relationship between age and attitudes towards AD diagnosis. It is concluded that the high rate of support for disclosure of AD diagnoses to patients among younger adults may reflect a change in the information preferences of patients brought about by a shift away from a patriarchal medical model, toward a more autonomous model of health.

A Preliminary Investigation of the Role of the Phenylalynine:Tyrosine Ratio in Children With Early and Continuously Treated Phenylketonuria: Toward Identification of Safe Levels

Children with early and continuously treated phenylketonuria (ECT-PKU) remain at risk of developing executive function (EF) deficits. There is some evidence that a high phenylalanine to tyrosine ratio (phe:tyr) is more strongly associated with impaired EF development than high phenylalanine alone. This study examined EF in a sample of 11 adolescents against concurrent and historical levels of phenylalanine, phe:tyr, and tyrosine. Lifetime measures of phe:tyr were more strongly associated with EF than phenylalanine-only measures. Children with a lifetime phe:tyr less than 6 demonstrated normal EF, whereas children who had a lifetime phe:tyr above 6, on average, demonstrated clinically impaired EF.

Biochemical markers associated with executive function in adolescents with early and continuously treated phenylketonuria.

Debate continues as to why executive function (EF) continues to show impairments in children with early and continuously treated phenylketonuria (ECT‐PKU). Using a mixed model, we measured EF in 10 adolescent children with ECT‐PKU and 6 sibling controls, and examined associations between EF and (1) phenylalanine (phe) and (2) the phenylalanine : tyrosine ratio (phe : tyr). Measurements were taken on two occasions anticipated to yield variation in concurrent biochemistry resulting from changes in dietary compliance (i.e. holiday vs non‐holiday period). A repeated measures anova using the Behaviour Rating Inventory of Executive Function yielded the following results: no significant interactions; two significant group effects of substantially impaired working memory and initiation skills in children with ECT‐PKU compared with controls, irrespective of occasion and two significant time effects, suggestive of slightly poorer non‐holiday planning and organization scores in both groups. Further analyses revealed that phe levels were not significantly different on these occasions, suggesting that holiday dietary compliance may be better than expected. Correlations between EF and biochemistry in children with PKU showed that participant’s lifetime phe : tyr ratio was positively and significantly associated with EF impairment, more so than phe‐only measures.

Comparison of MMPI-2 and PAI validity indicators to detect feigned depression and PTSD symptom reporting

The purpose of this study was to compare the clinical utility of PAI and MMPI-2 validity indicators to detect exaggeration of psychological symptoms. Participants were 49 (75.5% female) Australian university students who completed the MMPI-2 and PAI under one of three conditions: Control [i.e., honest responding (n=20)], Feign Post Traumatic Stress Disorder [PTSD (n=15)], or Feign Depression (n=14). Participants instructed to feign depression or feign PTSD had significantly higher scores on the majority of MMPI-2 and PAI validity indicators compared with controls. The Meyers Validity Index, the Obvious-Subtle index, and the Response Bias Scale were the most accurate MMPI-2 validity indicators. Diagnostic-specific MMPI-2 validity indicators, such as the Infrequency-PSTD scales and Malingered Depression scale, were not effective at detecting participants instructed to feign those conditions. For the PAI, the most accurate validity indicator was the MAL index; however, the detection rate using this validity indicator was modest at best. The MMPI-2 validity indicators were clearly superior to those on the PAI at identifying feigned versus honest responding in this sample.

Examining the influence of biological and psychological factors on cognitive performance in chronic fatigue syndrome: A randomized, double-blind, placebo-controlled, crossover study

The pathophysiology of chronic fatigue syndrome (CFS) remains unclear; however, both biological and psychological factors have been implicated in establishing or maintaining this condition. People with CFS report significant and disabling cognitive difficulties such as impaired concentration that in some cases are exacerbated by exposure to chemical triggers. The aim of this study was to determine if neuropsychological deficits in CFS are triggered by exposure to chemicals, or perceptions about the properties of these substances. Participants were 36 people with a primary diagnosis of CFS, defined according to Centers for Disease Control (CDC) criteria. A randomized, double-blind, placebo-controlled, crossover design was used, with objective assessment of neuropsychological function and participant rating of substance type, before and after exposure to placebo or chemical trigger. Results showed decrements in neuropsychological tests scores on three out of four outcome measures when participants rated the substance they had been exposed to as “chemical. ” No change in performance was found based on actual substance type. These results suggest that cognitive attributions about exposure substances in people with CFS may be associated with worse performance on neuropsychological tasks. In addition, these findings suggest that psychological interventions aimed at modifying substance-related cognitions may reduce some symptoms of CFS.

Depression, anxiety, and stress as predictors of postconcussion-like symptoms in a non-clinical sample.

This study examined the relationship between postconcussion-like symptoms and depressive symptoms, anxiety and stress respectively. Seventy-one university students with a negative concussion history completed the Depression Anxiety Stress Scales (DASS) and the British Columbia Postconcussion Symptom Inventory (BC-PSI). A multiple regression was conducted using the three DASS subscale scores as predictors of postconcussion-like symptoms. Depressive symptoms, anxiety and stress were significantly positively correlated with postconcussion-like symptoms at the bivariate level. When these three factors were examined together 72.9% of variance in BC-PSI total scores was explained overall. Stress and depressive symptoms emerged as significant multivariate predictors explaining 15% and 3% of unique variance, respectively. Anxiety was not a significant multivariate predictor. These results suggest that stress may be a more important predictor of postconcussion-like symptoms than previously identified. Findings are interpreted in light of Iverson (2012) conceptual model of poor outcomes from mild traumatic brain injury.