Psychometric evaluation of the Overall Anxiety Severity And Impairment Scale (OASIS) in individuals seeking outpatient specialty treatment for anxiety-related disorders.

BACKGROUND: Comorbidity among anxiety-related diagnoses is common, highlighting the need for brief, meaningful measures of anxiety that cut across diagnoses. METHODS: The current study examined the psychometric properties of one such measure, the Overall Anxiety Severity and Impairment Scale (OASIS) (Norman et al., 2006), in a naturalistic sample of individuals seeking treatment at an outpatient anxiety treatment center. We examined the measure׳s structure, convergent validity, and potential effects of respondent gender. Using ROC analysis, we estimated an optimal cut-score for determining presence of an anxiety disorder in this sample. Finally, we examined the responsiveness of the OASIS to clinical change and calculated a reliable change index. RESULTS: We found strong psychometric properties of the OASIS. A unitary factor structure with correlated residuals on the first two items provided the best fit to the data. A cut-score of eight best distinguished the presence of an anxiety-related diagnosis. In measurement invariance analyses, we found evidence that men and women respond similarly to the measure. In addition, we found that change in the OASIS was correlated with change in other measures, and we estimated that a four-point change in the OASIS can be considered clinically reliable. LIMITATIONS: Sample characteristics may limit generalizability. Diagnoses were established by clinicians using a semi-structured interview that, while based upon DSM-IV diagnostic criteria, has not been psychometrically evaluated. CONCLUSION: The results provide support for the use of the OASIS in specialty treatment for anxiety-related diagnoses and further highlight the strengths of this measure in clinical practice and research settings.

A longitudinal investigation of the relationship between disordered eating attitudes and behaviors and parent-child conflict: a monozygotic twin differences design.

Few studies have examined nonshared environmental risk factors for disordered eating, and none have done so using a longitudinal design. The current project used a longitudinal, monozygotic twin differences design to examine parent-child conflict as a nonshared environmental risk factor for disordered eating. Participants included 468 monozygotic female twins (234 pairs) from the Minnesota Twin Family Study, who completed surveys every 3 years from ages 11 to 17 years. Twin differences in disordered eating were assessed with the Total Score, Body Dissatisfaction, Weight Preoccupation, and Binge Eating subscales of the Minnesota Eating Behavior Survey. Differences in parent-child conflict were assessed with the Parental Environment Questionnaire. Cross-lagged models were used to examine longitudinal associations among these variables, controlling for within-age associations. Only the longitudinal association between twin differences in disordered eating at age 14 years and differences in parent-child conflict at age 17 years were significant; twin differences in disordered eating predicted later differences in parent-child conflict rather than the reverse. Findings suggest differences in parent-child conflict between genetically identical twins may be a consequence of, rather than a risk factor for, differences in disordered eating.

Age differences in genetic and environmental influences on weight and shape concerns.

OBJECTIVE: Previous research has shown important developmental shifts ingenetic and environmental influences for disordered eating. However, little research has examined age differences for weight/shape concerns, two key components of eating disorders. The goal of this study was to investigate these age differences in preadolescent, adolescent, young adult, and mid-adult twins. METHOD: Participants included 2,618 female twins (ages of 10-41 years) from three large twin registries. Shape and weight concerns were assessed with the Eating Disorders Examination Questionnaire. RESULTS: Genetic influences were modest in preadolescent twins, but significant from early-adolescence through middle adulthood. Shared environmental factors showed the opposite pattern, with the largest shared environmental contributions occurring in the youngest age group. Nonshared environmental effects remained relatively constant across age. DISCUSSION: Findings highlight the importance of age differences in genetic and environmental influences. Possible mechanisms include gene x environment interactions and biological changes associated with key developmental stages.

Do weight and shape concerns exhibit genetic effects? Investigating discrepant findings.

OBJECTIVE: Unlike twin studies of general weight and shape concerns, studies examining the heritability of the undue influence of weight and shape concerns on self-evaluation have found little evidence for genetic effects. The present study sought to resolve these discrepancies by examining the heritability of both types of weight and shape concerns in a young adult twin sample. METHOD: Participants included 270 female twins from the Michigan State University Twin Registry. General weight and shape concerns were assessed with subscales from the Eating Disorder Examination Questionnaire (EDEQ). Similar to previous research, the undue influence of weight and shape on self-evaluation was assessed using averaged scores from two EDEQ items. RESULTS: The heritability of all weight and shape measures was estimated at 49-66%. DISCUSSION: General weight and shape concerns and the undue influence of these concerns on self-evaluation are influenced by genetic factors in young adult female twins.

Baclofen for binge eating: an open-label trial.

OBJECTIVE: Baclofen is a GABA-B agonist that may be useful in the treatment of substance use disorders, and also reduces 'binge-like' eating in rodents. We hypothesized that baclofen might be effective in reducing binge eating episodes in binge eating disorder (BED) and bulimia nervosa (BN). METHOD: Seven women with BED (n = 4) or BN (n = 3) took baclofen (60 mg/day) for 10 weeks. RESULTS: Six out of seven patients completed the full 10-week trial. Five out of seven participants (3 BED; 2 BN) demonstrated 50% or greater reduction of frequency of binge eating from beginning to end of the study. Three out of seven participants (2 BED; 1 BN) were free of binge eating at study end. Four out of seven participants elected to continue baclofen at study end. Baclofen was well tolerated by the participants. CONCLUSION: In this open-label trial, baclofen was associated with decreased binge eating frequency in patients with BED and BN.