Edward R. Simco

Psychometric Properties of the Drug Use Disorders Identification Test (DUDIT) with Substance Abusers in Outpatient and Residential Treatment.

The psychometric properties of the Drug Use Disorders Identification Test (DUDIT), an 11-item self-report questionnaire developed to screen individuals for drug problems, are evaluated. The measure, developed in Sweden and evaluated there with individuals with severe drug problems, has not been evaluated with less severe substance abusers or with clinical populations in the United States. Participants included 35 drug abusers in an outpatient substance abuse treatment program, 79 drug abusers in a residential substance abuse treatment program, and 39 alcohol abusers from both treatment settings who did not report a drug abuse problem. The DUDIT was found to be a psychometrically sound drug abuse screening measure with high convergent validity (r=.85) when compared with the Drug Abuse Screening Test (DAST-10), and to have a Cronbachs alpha of .94. In addition, a single component accounted for 64.91% of total variance, and the DUDIT had sensitivity and specificity scores of .90 and .85, respectively, when using the optimal cut-off score of 8. Additionally, the DUDIT showed good discriminant validity as it significantly differentiated drug from alcohol abusers. These findings support the DUDIT as a reliable and valid drug abuse screening instrument that measures a unidimensional construct. Further research is warranted with additional clinical populations.

A Test of the Tripartite Model of Depression and Anxiety in Older Adult Psychiatric Outpatients

This study examined the tripartite model of depression and anxiety in 131 psychiatric outpatients, ages 55-87. Confirmatory factor analyses revealed that a 3-factor model provided an adequate fit to the observed data, that the 3-factor model was empirically superior to 1- or 2-factor models, and that the 3-factor structure obtained in the current sample of older adult outpatients converged with that obtained on a separate, younger sample. Negative affect was significantly related to depression and anxiety symptoms and syndromes, and positive affect was more highly related to depression than anxiety symptoms and syndromes. Ways for taking into account possible age-associated differences in emotion in older adults and thus improving the conceptual model of anxiety and depression are briefly noted.

Comparison of the Quick Drinking Screen and the Alcohol Timeline Followback with Outpatient Alcohol Abusers

Objective: A recent study comparing the Quick Drinking Screen (QDS) with the Timeline Followback (TLFB) found that in a nonclinical population of problem drinkers both measures produced reliable summary measures of drinking. The current study was designed to replicate these findings with a clinical population of alcohol abusers. The data were collected over three years (2004–2006). Method: Participants were 124 alcohol abusers who voluntarily enrolled for outpatient treatment. Over half (52.4%) were female with an average age of almost 40 years. About a third were married, had completed university, and a quarter were unemployed and nonwhite. Participants reported having a drinking problem for an average of 8.3 years, and reported drinking on about 5 days per week, averaging six drinks per drinking day. On two different occasions, they responded to two different sets of questions about their alcohol use. The instruments were: (a) the Quick Drinking Screen (QDS), a summary drinking measure, administered by telephone prior to the assessment; and (2) the TLFB self-administered by computer at the assessment. Results: As in a previous study, this study found that the QDS and the TLFB, two very different drinking measures, collected similar aggregate drinking data for four drinking variables in a clinical sample of alcohol abusers. Conclusions: When it is not necessary or not possible to gather detailed drinking data, the QDS produces reliable brief summary measures of drinking for problem drinkers. Generalization to nonclinical samples awaits further research.

Effects of Physical Exercise on Cognitive Functioning in the Elderly

In this paper, we summarize the effects of aging on physiological and cognitive processes in elderly individuals, discuss the ameliorative effects of physical exercising on these processes, and present a review of previous reports of the effects of physical exercise on cognitive functioning in the elderly. We also underscore issues concerning research design and methodology. Thirteen of 18 studies provided sufficient information for calculation of statistical power and effect sizes. Although these studies included a total of 87 statistical tests, the power exceeded. 4 in only 10 instances. Despite inadequate power, effects of exercise were strong enough to yield significant results (<.05) in 23 of these tests. Of the 87 effect sizes determined by using pre- to postassessment data for the exercise group, 56 fell within the very small to medium range (.04 to .49), and 15 fell within the medium to large range (.05 to 1.59). We conclude that exercise promotes modest changes in cognitive functioning in the aged. Given demonstrated improvements in both physical and psychological health, a sound empirical basis exists for prescription of exercise for older adults.

Shorter and Proximal Timeline Followback Windows are Representative of Longer Posttreatment Functioning.

Very little research has been conducted on what time window provides a representative picture of daily drinking. With respect to pretreatment drinking, one study that used the Timeline Followback (TLFB) with problem drinkers found that a 3-month window is generally representative of annual pretreatment drinking. The objective of the present study was to determine the shortest representative time window for reports of annual posttreatment drinking. A second objective was to determine which of two time windows, 90 days from the end of treatment or 90 days prior to the end of follow-up, was the most representative proxy for annual posttreatment drinking. TLFB reports from 467 problem drinkers who participated in a randomized controlled trial of a mail-based intervention were used in the present analysis. The results show that a 3-month posttreatment window (i.e., first 90 days after the intervention) is sufficiently representative (r = .94) of annual posttreatment drinking for problem drinkers (i.e., less severely dependent alcohol abusers). In addition, although there were no clinically significant differences in drinking behavior between the two 90-day posttreatment windows, the use of proximal windows (i.e., closer to the end of treatment) would minimize participant attrition. In addition, a 3-month versus 12-month TLFB follow-up time frame resulted in a much higher percentage of participants completing the full TLFB (89% vs. 71%). Further research is needed to determine if these findings will generalize to more severely dependent alcohol abusers.

Abbreviated form of the Wisconsin Card Sort Test.

While the Wisconsin Card Sort Test is a popular procedure used to evaluate executive functions. the test may take extended times to administer. especially in impaired clients. This has led to interest in the development of a short form of the test. Axelrod. Paolo. and Abraham (1997) earlier failed in an attempt to develop a short form of the Wisconsin Card Sort Test (WCS ‘I’). The authors suggested that a regression-based approach might work better than their predictive model. In a sample of 145 consecutive subjects referred for neuropsychological testing. linear and nonlinear regression for- mulas were generated to predict the full 128 card version of the test from 32, 64. and 96 item versions of the test. Overall. the data obtained strongly suggests that multiple regression equations can reliably predict WCST whole test scores from a 64 or a 96-item version of the test. but not a 32-item version. The results indicate that the 64-item version is a clinically sound substitute for the entire test.

A Two-Layer Model of the North Atlantic Thermocline

Abstract A two-layer model of a mid-oceanic thermocline is developed, and a comparison of the depth and temperature of the thermocline in this model is made with a root-mean-square description of the hydrographic structure of the North Atlantic. It is shown that the Sverdrup balance is maintained within the rms errors, and the entire estimated heat flux from the atmosphere is used to produce the observed density changes along the path of persistent flow.

Rates of Apparently Abnormal MMPI-2 Profiles in the Normal Population

MMPI-2 standardization data were re-sampled using Monte Carlo simulations to estimate the base rate of apparently abnormal scores expected by chance in the normal population when multiple scales are interpreted. 36.8% of normal adults are likely to obtain a score that would otherwise be considered clinically significant at 65T on one or more of the 10 Clinical scales. The normal incidence of at least one apparently abnormal score was 38.3% on the Content and 55.1% on the Supplementary scales. When the Clinical, Supplementary, and Content scales and subscales are interpreted together, at least three seemingly meaningful scores will be found in 47.4% of perfectly normal individuals, and five or more scales that appear to be clinically significant can be expected in 30.1% of cases that are actually unremarkable. These results imply that the number of MMPI-2 scales that can be meaningfully interpreted in clinical practice is limited, and that high T-scores are necessary for an adequate level of confidence even when interpretation is appropriately limited to the Clinical scales.

Apparently Abnormal Wechsler Memory Scale Index Score Patterns in the Normal Population

Interpretation of the Wechsler Memory Scale-Fourth Edition may involve examination of multiple memory index score contrasts and similar comparisons with Wechsler Adult Intelligence Scale-Fourth Edition ability indexes. Standardization sample data suggest that 15-point differences between any specific pair of index scores are relatively uncommon in normal individuals, but these base rates refer to a comparison between a single pair of indexes rather than multiple simultaneous comparisons among indexes. This study provides normative data for the occurrence of multiple index score differences calculated by using Monte Carlo simulations and validated against standardization data. Differences of 15 points between any two memory indexes or between memory and ability indexes occurred in 60% and 48% of the normative sample, respectively. Wechsler index score discrepancies are normally common and therefore not clinically meaningful when numerous such comparisons are made. Explicit prior interpretive hypotheses are necessary to reduce the number of index comparisons and associated false-positive conclusions. Monte Carlo simulation accurately predicts these false-positive rates.

Pattern of Memory Compromise in Chronic Geriatric Schizophrenia, Frontotemporal Dementia, and Normal Geriatric Controls.

Objective: The purpose of this study was to explore whether memory deficits in schizophrenia are attributable to poor organisation/encoding during initial learning vs. memory decay. Methods: Subjects included geriatric schizophrenia/schizoaffective disorders [SSD; n = 37; age = 59.92 (55–74); education = 11.70 (7–18)]; frontotemporal dementia [FTD; n = 41; age = 76.59 (64–83); education = 14.61 (12–20)] and geriatric controls [n = 107; age = 70.97 (55–93); education = 13.76 (6–20)]. Subjects were administered the Wechsler Memory Scale, Third Edition and discrepancy scores between immediate and delayed subtests/indices were used to explore possible differences between groups in pattern of impairment. Results: Significant differences were found between groups on age/education and these variables were related to several outcome measures. Gender was not related to diagnostic group and there were no gender differences on study variables. There were differences between the SSD subjects on several variables, with the schizoaffective subjects performing worse despite equivalence on global cognitive function, living status and chronicity. Seven one-way between-subjects ANCOVAs compared groups on discrepancy scores. Results failed to suggest differences between groups on immediate-delayed memory discrepancy scores (p> 0.05). Subsequent analyses revealed differences in percentage retention scores between SSD and FTD on the faces subtest (p = 0.040), with SSD retaining greater information over time. Conclusion: Results failed to show distinctions between groups on pattern of memory impairment when using discrepancy comparisons. However, an analysis examining percentage retention scores revealed better maintenance of non-contextual visual information over time in SSD. Findings may suggest deficits in immediate encoding rather than memory decay for some types of memory ability among geriatric SSD. Our failure to document group differences when using discrepancy comparisons may be attributable to relative similarity in pattern between groups or the limited sensitivity of this technique.