Matthew Sunderland

Normative Data for the 12 Item WHO Disability Assessment Schedule 2.0

Background The World Health Organization Disability Assessment Schedule (WHODAS 2.0) measures disability due to health conditions including diseases, illnesses, injuries, mental or emotional problems, and problems with alcohol or drugs. Method The 12 Item WHODAS 2.0 was used in the second Australian Survey of Mental Health and Well-being. We report the overall factor structure and the distribution of scores and normative data (means and SDs) for people with any physical disorder, any mental disorder and for people with neither. Findings A single second order factor justifies the use of the scale as a measure of global disability. People with mental disorders had high scores (mean 6.3, SD 7.1), people with physical disorders had lower scores (mean 4.3, SD 6.1). People with no disorder covered by the survey had low scores (mean 1.4, SD 3.6). Interpretation The provision of normative data from a population sample of adults will facilitate use of the WHODAS 2.0 12 item scale in clinical and epidemiological research.

Psychometric Comparison of the PHQ-9 and BDI-II for Measuring Response during Treatment of Depression

The Patient Health Questionnaire-9 Item (PHQ-9) and Beck Depression Inventory–II (BDI-II) are frequently used measures of depression severity, but little is known about their relative psychometric properties. The authors assessed psychometric properties of both measures during treatment for depression. The PHQ-9 and BDI-II scores from 172 depressed participants in two randomized controlled trials of treatment for depression were assessed and combined. Tests of internal consistency (Cronbachs α), factor analyses, correlational analyses, estimates of clinically significant change, and effect sizes (Cohens d) were calculated after treatment and follow-up. Both scales demonstrated adequate internal consistency at pre- and posttreatment (PHQ-9 α = .74 and .81; BDI-II α = .87 and .90, respectively). Factor analysis failed to confirm the one-factor model previously reported for the PHQ-9, but two factors evidenced good fit for the BDI-II. Both scales converged more with each other than with the Sheehan Disability Scale at pre- but not at posttreatment. Responsiveness to change of PHQ-9 and BDI-II was similar at both posttreatment and follow-up. The consistency of agreement on indices of clinical significance was fair to moderate, but the BDI-II categorised a greater proportion of participants with severe depression than the PHQ-9. The BDI-II and PHQ-9 demonstrated adequate reliability, convergent/discriminant validity, and similar responsiveness to change. Differences were found in how they categorised severity. Pending the results of further studies, the attributes of the PHQ-9, of being shorter and based on the diagnostic criteria for depression, may indicate an advantage over the BDI-II.

Psychometric Comparison of the Generalized Anxiety Disorder Scale-7 and the Penn State Worry Questionnaire for Measuring Response during Treatment of Generalised Anxiety Disorder

The Penn State Worry Questionnaire (PSWQ) is a widely used measure of the worry characteristic of generalised anxiety disorder (GAD). The 7-item Generalized Anxiety Disorder Scale (GAD-7) is a new brief screening tool for GAD, which is being increasingly used in research and clinical practice. The present study sought to provide comparison data on the relative psychometric properties of these two scales. The data of 195 adults who met Diagnostic and Statistical Manual of Mental Disorders (DSM-IV) criteria for GAD and who participated in two randomised treatment controlled trials were used. Factor analyses, internal consistency, correlational analyses, responsiveness to change, and agreement between the scales based on indentified clinical cutoffs were conducted. Factor analyses confirmed a one-factor structure for the GAD-7 and a three-factor structure involving two method factors for the PSWQ. Both the GAD-7 and the PSWQ demonstrated adequate internal consistency (Cronbachs alpha: .79–.91 and .86–.91, respectively), and moderate correlations (r = .51–.71) were observed between the scales across the treatment time points. The scales exhibited small correlations with the Sheehan Disability Scale at pretreatment (GAD-7 r = .38; PSWQ r = .26), but moderate correlations at posttreatment and follow-up (r = .59–.79). Agreement between the scales was limited using various clinical cutoffs identified within the literature. Both measures were sensitive to change, although the GAD-7 appeared to be more sensitive and may, therefore, confer some advantages in clinical work.

Adherence as a determinant of effectiveness of internet cognitive behavioural therapy for anxiety and depressive disorders.

Since 2009, the Clinical Research Unit for Anxiety and Depression (CRUfAD) has been providing primary care clinicians with internet cognitive behaviour therapy (iCBT) courses to prescribe to patients. Although these courses have demonstrated efficacy in research trials, adherence in primary care is less than half that of the research trials. The present studies pose three questions: first, do course non-completers drop out because of lack of efficacy? Second, can changes in delivery (e.g. adding choice, reminders and financial cost) improve adherence? Last, does clinician contact improve adherence? The results showed that non-completers derive benefit before dropping out; that adding reminders, choice of course and timing, and financial cost can significantly improve adherence; and that clinician contact during the course is associated with increased adherence. It is concluded that improved adherence is an important determinant of effectiveness.

Psychotic-like experiences in a community sample of 8000 children aged 9 to 11 years: an item response theory analysis

BACKGROUND Psychotic-like experiences (PLEs) in the general population are common, particularly in childhood, and may constitute part of a spectrum of normative development. Nevertheless, these experiences confer increased risk for later psychotic disorder, and are associated with poorer health and quality of life. METHOD This study used factor analytic methods to determine the latent structure underlying PLEs, problem behaviours and personal competencies in the general child population, and used item response theory (IRT) to assess the psychometric properties of nine PLE items to determine which items best represented a latent psychotic-like construct (PSY). A total of 7966 children aged 9-11 years, constituting 95% of eligible children, completed self-report questionnaires. RESULTS Almost two-thirds of the children endorsed at least one PLE item. Structural analyses identified a unidimensional construct representing psychotic-like severity in the population, the full range of which was well sampled by the nine items. This construct was discriminable from (though correlated with) latent dimensions representing internalizing and externalizing problems. Items assessing visual and auditory hallucination-like experiences provided the most information about PSY; delusion-like experiences identified children at more severe levels of the construct. CONCLUSIONS Assessing PLEs during middle childhood is feasible and supplements information concerning internalizing and externalizing problems presented by children. The hallucination-like experiences constitute appropriate items to screen the population to identify children who may require further clinical assessment or monitoring. Longitudinal follow-up of the children is required to determine sensitivity and specificity of the PLE items for later psychotic illness.

Health anxiety in Australia: prevalence, comorbidity, disability and service use

BACKGROUND Health anxiety is associated with high distress, disability and increased health service utilisation. However, there are relatively few epidemiological studies examining the extent of health anxiety or the associated sociodemographic and health risk factors in the general population. AIMS To provide epidemiological data on health anxiety in the Australian population. METHOD Lifetime and current prevalence estimates, associations between comorbid disorders, psychological distress, impairment, disability and mental health service utilisation were generated using the Australian 2007 National Survey of Mental Health and Wellbeing. RESULTS Health anxiety affects approximately 5.7% of the Australian population across the lifespan and 3.4% met criteria for health anxiety at the time of the interview. Age, employment status, smoking status and comorbid physical conditions were significantly related to health anxiety symptoms. Health anxiety was associated with significantly more distress, impairment, disability and health service utilisation than that found in respondents without health anxiety. CONCLUSIONS Health anxiety is non-trivial; it affects a significant proportion of the population and further research and clinical investigation of health anxiety is required.

Classification of anxiety and depressive disorders: problems and solutions.

The American Psychiatric Association and the World Health Organization have begun to revise their classifications of mental disorders. Four issues related to these revisions are discussed in this study: the structure of the classifications, the relationship between categories and dimensions, the sensitivity of categorical thresholds to definitions, and maximizing the utility and validity of the diagnostic process. There is now sufficient evidence to consider replacing the present groupings of disorders with an empirically based structure that reflects the actual similarities among disorders. For example, perhaps the present depression and anxiety disorders would be best grouped as internalizing disorders. Most mental disorders exist on a severity dimension. The reliability and validity of the classification might be improved if we accepted the dimensional nature of disorders while retaining the use of categorical diagnoses to enhance clinical utility. Definitions of the thresholds that define categories are very susceptible to detail. In International Classification of Diseases‐11(ICD‐11) and Diagnostic and Statistical Manual of Mental Disorders‐V (DSM‐V), disorders about which there is agreement should be identically defined, and disorders in which there is disagreement should be defined differently, so that research can identify which definition is more valid. The present diagnostic criteria are too complex to have acceptable clinical utility. We propose a reduced criterion set that can be remembered by clinicians and an enhanced criterion set for use with decision support tools. Depression and Anxiety 25:274–281, 2008.

Development of a short form Social Interaction Anxiety (SIAS) and Social Phobia Scale (SPS) using nonparametric item response theory: the SIAS-6 and the SPS-6.

Shortened forms of the Social Interaction Anxiety Scale (SIAS) and the Social Phobia Scale (SPS) were developed using nonparametric item response theory methods. Using data from socially phobic participants enrolled in 5 treatment trials (N = 456), 2 six-item scales (the SIAS-6 and the SPS-6) were developed. The validity of the scores on the SIAS-6 and the SPS-6 was then tested using traditional methods for their convergent validity in an independent clinical sample and a student sample, as well as for their sensitivity to change and diagnostic sensitivity in the clinical sample. The scores on the SIAS-6 and the SPS-6 correlated as well as the scores on the original SIAS and SPS, with scores on measures of related constructs, discriminated well between those with and without a diagnosis of social phobia, providing cutoffs for diagnosis and were as sensitive to measuring change associated with treatment as were the SIAS and SPS. Together, the SIAS-6 and the SPS-6 appear to be an efficient method of measuring symptoms of social phobia and provide a brief screening tool.

Investigating trajectories of change in psychological distress amongst patients with depression and generalised anxiety disorder treated with internet cognitive behavioural therapy.

Internet based cognitive behavioural therapy (CBT) is efficacious for the treatment of anxiety and depression. The current study aimed to examine the effectiveness of internet based CBT prescribed by primary care clinicians for the treatment of depression and generalised anxiety disorder. Psychological distress data from 302 patients who completed an online CBT course for depression and 361 patients who completed an online CBT course for generalised anxiety disorder were subjected to growth mixture analysis. For both disorders psychological distress decreased across each lesson in a quadratic trend. Two classes of individuals were identified with different trajectories of change: a large group of individuals who responded well to the courses and a smaller group of individuals with a lower response. Both groups were similar with respect to socio-demographic characteristics however the Low Responders tended to have higher levels of symptom severity and psychological distress at baseline in comparison to the responders. For the majority of patients (75-80%) the internet CBT courses for depression and generalised anxiety disorder were effective. Further research is required to identify and effectively treat the smaller proportion of patients who did not improve during internet CBT.

The structure of adolescent psychopathology: a symptom-level analysis

BACKGROUND Most empirical studies into the covariance structure of psychopathology have been confined to adults. This work is not developmentally informed as the meaning, age-of-onset, persistence and expression of disorders differ across the lifespan. This study investigates the underlying structure of adolescent psychopathology and associations between the psychopathological dimensions and sex and personality risk profiles for substance misuse and mental health problems. METHOD This study analyzed data from 2175 adolescents aged 13.3 years. Five dimensional models were tested using confirmatory factor analysis and the external validity was examined using a multiple-indicators multiple-causes model. RESULTS A modified bifactor model, with three correlated specific factors (internalizing, externalizing, thought disorder) and one general psychopathology factor, provided the best fit to the data. Females reported higher mean levels of internalizing, and males reported higher mean levels of externalizing. No significant sex differences emerged in liability to thought disorder or general psychopathology. Liability to internalizing, externalizing, thought disorder and general psychopathology was characterized by a number of differences in personality profiles. CONCLUSIONS This study is the first to identify a bifactor model including a specific thought disorder factor. The findings highlight the utility of transdiagnostic treatment approaches and the importance of restructuring psychopathology in an empirically based manner.