Andrew Mackinnon

A short form of the Positive and Negative Affect Schedule : evaluation of factorial validity and invariance across demographic variables in a community sample

Abstract The existence of two nearly-orthogonal dimensions of positive and negative affect was established for a ten-item short form of the Positive and Negative Affect Schedule using confirmatory factor analytic techniques in a large probability sample (n=2651) spanning ages 18 to 79. The factor structure and factor correlations were found to be unchanged with age. A multiple indicators, multiple causes model was used to investigate differences in item responses according to age, sex, education, marital status and financial hardship that could not be accounted for by differences in affect levels between groups. Only one item, excited from the Positive Affect scale, was found to elicit differential responses. While improvements to the Positive Affect scale might be desirable, the Short PANAS can be recommended for use when measures of positive and negative affect are required.

People living with psychotic illness in 2010: the second Australian national survey of psychosis.

Objective: The 2010 Survey of High Impact Psychosis (SHIP) is Australia’s second national psychosis survey. This paper provides an overview of its findings, including comparisons with the first psychosis survey and general population data. Methods: The survey covered 1.5 million people aged 18–64 years, approximately 10% of Australians in this age group. A two-phase design was used. In phase 1, screening for psychosis took place in public mental health services and non-government organizations supporting people with mental illness. In phase 2, 1825 of those screen-positive for psychosis were randomly selected and interviewed. Data collected included symptomatology, substance use, functioning, service utilization, medication use, education, employment, housing, and physical health including fasting blood samples. Results: The estimated 1-month treated prevalence of psychotic disorders in public treatment services was 3.1 people per 1000 population; the 12-month treated prevalence was 4.5 people per 1000. The majority (63.0%) of participants met ICD-10 criteria for schizophrenia/schizoaffective disorder. One-half (49.5%) reported attempting suicide in their lifetime and two-thirds (63.2%) were rated as impaired in their ability to socialize. Over half (54.8%) had metabolic syndrome. The proportion currently smoking was 66.1%. Educational achievement was low. Only 21.5% were currently employed. Key changes in the 12 years since the first survey included: a marked drop in psychiatric inpatient admissions; a large increase in the proportion attending community mental health clinics; increased use of rehabilitation services and non-government organizations supporting people with mental illness; a major shift from typical to atypical antipsychotics; and large increases in the proportions with lifetime alcohol or drug abuse/dependence. Conclusion: People with psychotic illness face multiple challenges. An integrated approach to service provision is needed to ensure that their living requirements and needs for social participation are met, in addition to their very considerable mental and physical health needs.

A spreadsheet for the calculation of comprehensive statistics for the assessment of diagnostic tests and inter-rater agreement

While advances in statistical methods allow greater insight into the characteristics of diagnostic tests and of raters, researchers frequently rely on incomplete or inappropriate indices of performance. Lack of available computer software is probably an important barrier to optimal use of data collected to evaluate diagnostic tests and agreement between raters. A spreadsheet has been designed to provide comprehensive statistics for the assessment of diagnostic tests and inter-rater reliability when these investigations yield data that can be summarized in a 2x2 table. As well as a wide range of indices of test or rater performance, confidence intervals for these quantities are also calculated by the spreadsheet.

Apolipoprotein E allele ∈4, dementia, and cognitive decline in a population sample

From clinically based series it has been proposed that, in homozygotes for the apolipoprotein E epsilon 4 (apoE epsilon 4) allele, Alzheimers disease is almost inevitable by the age of 80. A population sample of persons aged 70 years and over was interviewed in 1990-91 to ascertain the presence of dementia or cognitive impairment. The sample was reinterviewed in 1994, when the apoE genotype was also determined. Prevalence data for the 638 persons who completed the second examination revealed a linear association between having an apoE epsilon 4 allele and both dementia and cognitive impairment (for heterozygotes, odds ratio for dementia 1.89, 95% confidence interval 1.04-3.44 and for homozygotes OR 3.58, 95% CI 1.08-11.82; both adjusted for age). However, even in subjects homozygous for epsilon 4 the estimated prevalence of dementia by age 90 was only about 50%. Persons with one or two epsilon 4 alleles were more likely to have a family history of dementia than those with none. This study confirms in a population sample that the epsilon 4 allele is a risk factor for dementia, but refutes the suggestion that homozygosity for the epsilon 4 allele is sufficient for the development of Alzheimers disease: persons with either one or two epsilon 4 alleles may reach late old age without cognitive impairment.

Performance of the Informant Questionnaire on Cognitive Decline in the Elderly (IQCODE) as a screening test for dementia

A 26-item informant questionnaire (IQCODE) and the Mini-Mental State Examination (MMSE) were compared as screening tests for dementia in a sample of 69 patients. Dementia diagnoses were made by both a clinician and a research interview using a computer algorithm to meet DSM-III-R and ICD-10 (Draft) criteria. The IQCODE was found to perform at least as well as the MMSE against all diagnoses and significantly better when judged against the algorithmic ICD-10 diagnoses. Also, the IQCODE was found to be uncontaminated by pre-morbid ability as estimated from the National Adult Reading Test and to have very high test-retest reliability after a delay of a day or more.

The YouthMood Project: a cluster randomized controlled trial of an online cognitive behavioral program with adolescents.

The aim in the current study was to investigate the effectiveness of an online, self-directed cognitive-behavioral therapy program (MoodGYM) in preventing and reducing the symptoms of anxiety and depression in an adolescent school-based population. A cluster randomized controlled trial was conducted with 30 schools (N = 1,477) from across Australia, with each school randomly allocated to the intervention or wait-list control condition. At postintervention and 6-month follow-up, participants in the intervention condition had significantly lower levels of anxiety than did participants in the wait-list control condition (Cohens d = 0.15-0.25). The effects of the MoodGYM program on depressive symptoms were less strong, with only male participants in the intervention condition exhibiting significant reductions in depressive symptoms at postintervention and 6-month follow-up (Cohens d = 0.27-0.43). Although small to moderate, the effects obtained in the current study provide support for the utility of universal prevention programs in schools. The effectiveness of booster sessions should be explored in future research.

The course of depression in the elderly : a longitudinal community-based study in Australia

BACKGROUND We report the outcome of depressive states after 3-4 years in a community sample of the elderly. METHODS A sample of 1045 persons aged 70+ years in 1990-1 was re-interviewed after 3.6 years. RESULTS Mortality (21.7%) and refusal or non-availability (10.4%) were higher in those who initially had had a diagnosis or symptoms of depression. Of those with an ICD-10 depressive episode in 1990-1, 13% retained that diagnosis. Of those who were not depressed initially only 2.5% had become cases. Depression was unrelated to age or apolipoprotein E genotype. The best predictors of the number of depressive symptoms at follow-up was the number at Wave 1, followed by deterioration in health and in activities of daily living, high neuroticism, poor current health, poor social support, low current activity levels and high service use. Depressive symptoms at Wave 1 did not predict subsequent cognitive decline or dementia. CONCLUSIONS Non-random sample attrition is unavoidable. ICD-10 criteria yield more cases than other systems, while continuous measures of symptoms confer analytical advantages. Risk factors for depressive states in the elderly have been further identified. The prognosis for these states is favourable. At the community level, depressive symptoms do not seem to predict cognitive decline, as they do in referred series.

Paediatric quality of life instruments: a review of the impact of the conceptual framework on outcomes.

With an increasing number of paediatric quality of life (QOL) instruments being developed, it is becoming difficult for researchers and clinicians to select the most appropriate instrument. Reviews of QOL instruments tend to report only basic properties of the instruments such as domains and psychometric properties. This paper seeks to appraise critically the conceptual underpinnings of paediatric QOL instruments. A systematic review was conducted to identify QOL instruments for children aged 0 to 12 years, and to examine and compare their conceptual frameworks, definitions employed, and structure. Both generic and condition‐specific measures were reviewed. Fourteen generic and 25 condition‐specific QOL instruments were identified. Eleven types of definition of QOL and health‐related QOL and three theories of QOL were identified. QOL was measured by a variety of domains including emotional, social and physical health, and well‐being. Items commonly assessed difficulties, or intensity/frequency of feelings/symptoms, in contrast to positive aspects of life and happiness. The findings highlight the diversity that is apparent in the conceptualization of paediatric QOL and draw attention to the lack of empirical evidence for many of the fundamental assumptions. The impact of the conceptual underpinnings of the instruments on the resulting QOL scores is discussed.

Online randomized controlled trial of brief and full cognitive behaviour therapy for depression

BACKGROUND Effective internet-based programs for depression usually incorporate a component that provides telephone or email contact. Open access websites, without such contact, show high rates of attrition and poorer outcomes. The present study was designed as an exploratory investigation of the parameters that influence the effectiveness and retention of users on open access websites. We investigated whether brief cognitive behaviour therapy (CBT) was as effective as an extended version, whether add-on components of behaviour therapy or stress management contributed to positive outcomes, and whether longer programs were associated with greater attrition. METHOD An online randomized controlled trial (RCT) was conducted between 13 January 2005 and 26 May 2005 (19 weeks). A total of 2794 registrants (1846 women and 948 men; median age category 35-44 years) with elevated scores on the Goldberg Depression Scale of 5.96 (S.D.=2.09) elected online to be randomized to one of six versions of a CBT website. The versions were compiled consisting of various components of brief CBT, extended CBT, behaviour strategies, stress management and problem solving. RESULTS A total of 20.4% of participants completed the assigned intervention. The interaction of measurement occasion and treatment version was significant [F(13,131)=2.20, p=0.01]. A single module of brief introductory CBT was not effective in reducing depression symptoms. However, extended CBT with or without the addition of behaviour strategies resulted in the reduction of depression. CONCLUSIONS Brief CBT-based interventions are not as effective as extended interventions. However, longer programs are associated with higher rates of dropout.

Do cognitive complaints either predict future cognitive decline or reflect past cognitive decline? A longitudinal study of an elderly community sample

Data from a two-wave longitudinal study of an elderly community sample were used to assess whether cognitive complaints either predict subsequent cognitive decline or reflect past cognitive decline. Cognitive complaints and cognitive functioning were assessed on two occasions three and a half years apart. Cognitive complaints at Wave 1 were found not to predict future cognitive change on the Mini-Mental State Examination, an episodic memory test or a test of mental speed. Similarly, cognitive complaints at Wave 2 were unrelated to past cognitive changes on these tests after statistically controlling for the effects of anxiety and depression. Furthermore, cognitive complaints did not predict either mortality (after controlling for anxiety and depression) or future dementia. These results are evidence against the inclusion of cognitive complaints in diagnostic criteria for proposed disorders such as age-associated memory impairment, mild cognitive disorder and ageing-associated cognitive decline.