Predictors of treatment outcome for youth receiving intensive residential treatment for obsessive–compulsive disorder (OCD)

ABSTRACT

Little is known about the predictors of outcome from intensive residential treatment of OCD. This study aimed to examine age, gender, and baseline OCD severity, as well as measures of comorbid anxiety and depressive, internalizing/externalizing, and inattention symptoms, as predictors of treatment outcome in adolescents receiving intensive residential treatment for OCD.

The sample comprised 314 adolescents aged 13–17 years with treatment-resistant OCD and a Children’s Yale–Brown Obsessive–Compulsive Scale Self-Report (CY-BOCS-SR) total score ≥16. Bivariate and multiple regression models were used to evaluate the predictors of continuous OCD severity outcome and treatment response.

Results of the bivariate regression analyses of predictors demonstrated that length of treatment, pre-treatment OCD severity, and symptoms of anxiety and depression significantly predicted post-treatment OCD severity, while only symptoms of depression and anxiety predicted treatment response. When including all predictors in the same model, only baseline OCD severity remained a significant predictor of post-treatment OCD severity, and none of the assessed variables significantly predicted treatment response.

Results indicate that low pre-treatment OCD severity predicts lower OCD severity following treatment, although it did not predict treatment response.     

Is there anything out there? A study of distal attribution in response to vibrotactile stimulation

Patterns of vibrotactile stimulation were delivered to the index fingertips of naive blindfolded subjects. The attributions made by these subjects when they were allowed to experience transformations of vibrotactile stimulation correlated with self-movement were assessed. Although the subjects became aware of the relationship between self-movement and stimulation transformation, they never developed the hypothesis of distal attribution, ie the hypothesis that the ultimate cause of their vibrotactile experience was an encounter with an object in the environment. It is proposed that further investigations of the course of acquisition of distal attribution in the situation described may be instructive in the study of externalization in other modalities.     

Model Selection of Nested and Non-Nested Item Response Models Using Vuong Tests

Abstract

In this paper, we apply Vuong’s general approach of model selection to the comparison of nested and non-nested unidimensional and multidimensional item response theory (IRT) models. Vuong’s approach of model selection is useful because it allows for formal statistical tests of both nested and non-nested models. However, only the test of non-nested models has been applied in the context of IRT models to date. After summarizing the statistical theory underlying the tests, we investigate the performance of all three distinct Vuong tests in the context of IRT models using simulation studies and real data. In the non-nested case we observed that the tests can reliably distinguish between the graded response model and the generalized partial credit model. In the nested case, we observed that the tests typically perform as well as or sometimes better than the traditional likelihood ratio test. Based on these results, we argue that Vuong’s approach provides a useful set of tools for researchers and practitioners to effectively compare competing nested and non-nested IRT models.