Using Factor Mixture Models to Evaluate the Type A/B Classification of Alcohol Use Disorders in a Heterogeneous Treatment Sample

BACKGROUND: The type A/B classification model for alcohol use disorders (AUDs) has received considerable empirical support. However, few studies examine the underlying latent structure of this subtyping model, which has been challenged as a dichotomization of a single drinking severity dimension. Type B, relative to type A, alcoholics represent those with early age of onset, greater familial risk, and worse outcomes from alcohol use. METHOD: We examined the latent structure of the type A/B model using categorical, dimensional, and factor mixture models in a mixed gender community treatment-seeking sample of adults with an AUD. RESULTS: Factor analytic models identified 2-factors (drinking severity/externalizing psychopathology and internalizing psychopathology) underlying the type A/B indicators. A factor mixture model with 2-dimensions and 3-classes emerged as the best overall fitting model. The classes reflected a type A class and two type B classes (B1 and B2) that differed on the respective level of drinking severity/externalizing pathology and internalizing pathology. Type B1 had a greater prevalence of women and more internalizing pathology and B2 had a greater prevalence of men and more drinking severity/externalizing pathology. The 2-factor, 3-class model also exhibited predictive validity by explaining significant variance in 12-month drinking and drug use outcomes. CONCLUSIONS: The model identified in the current study may provide a basis for examining different sources of heterogeneity in the course and outcome of AUDs

Patient descriptions of loss of control and eating episode size interact to influence expert diagnosis of ICD-11 binge-eating disorder

Background Although data suggest that the sense of “loss of control” (LOC) is the most salient aspect of binge eating, the definition of LOC varies widely across eating disorder assessments. The WHO ICD-11 diagnostic guidelines for binge eating do not require an objectively large amount of food, which makes accurate LOC diagnosis even more critical. However, it can be especially challenging to assess LOC in the context of elevated weight status and in the absence of compensatory behaviors. This ICD-11 field sub-study examined how descriptions of subjective experience during distressing eating episodes, in combination with different eating episode sizes, influence diagnoses of binge-eating disorder (BED). Method Mental health professionals with eating disorder expertise from WHO’s Global Clinical Practice Network (N = 192) participated in English, Japanese, and Spanish. Participants were asked to select the correct diagnosis for two randomly assigned case vignettes and to rate the clinical importance and ease of use of each BED diagnostic guideline. Results The presence of LOC interacted with episode size to predict whether a correct diagnostic conclusion was reached. If the amount consumed during a typical distressing eating episode was only subjectively large compared to objectively large, clinicians were 23.1 times more likely to miss BED than to correctly diagnose it, and they were 9.7 times more likely to incorrectly diagnose something else than to correctly diagnose BED. In addition, clinicians were 10.8 times more likely to make a false positive diagnosis of BED when no LOC was described if the episode was objectively large. Descriptions of LOC that were reliably associated with correct diagnoses across episodes sizes included two that are similar to those already included in proposed ICD-11 guidelines and a third that is not. This third description of LOC focuses on giving up attempts to control eating because perceived overeating feels inevitable. Conclusions Results highlight the importance of detailed clarification of the LOC construct in future guidelines. Explicitly distinguishing LOC from distressing and mindless overeating could help promote consistent and accurate diagnosis of BED versus another or no eating disorder

Hormonal responses among normal-weight adolescents and obese teenagers undergoing laparoscopic adjustable gastric banding

Background: Bariatric procedures such as laparoscopic adjustable gastric banding (LAGB) can markedly decrease body adiposity in severely obese adolescents, but relatively little is known about the short-term effects of such procedures on meal-related hormonal response. Methods: Participants completed a fixed size breakfast meal and fasting concentrations of appetitive hormones (leptin, insulin/glucose, ghrelin, PYY) were measured. PYY, ghrelin, and visual analog scale (VAS) ratings of fullness, hunger, nausea, and desire to eat were assessed immediately before the meal and 15, 30, 60, and 90 minutes afterwards. Results: A total of 10 normal-weight controls (age: 15.4±2.0 years, BMI: 21.3±1.7 kg/m2; n=5 female) and 21 severely obese (age: 16.1±1.0 years, BMI: 46.4±6.6 kg/m2; n=18 females) adolescents were studied pre-LAGB. Eleven of the obese adolescents were studied again 122.6±17.8 days post-LAGB (BMI 40.9±7.8 kg/m2, mean change in BMI: −3.5±2.5 kg/m2). In comparison to normal-weight controls, surgical candidates had significantly higher fasting insulin and leptin and lower fasting ghrelin. Fasting PYY decreased significantly post-surgery. Meal-related suppression of ghrelin, as measured by area under the curve (AUC), was significantly less in absolute value among pre-operative candidates than among normal weight controls [t(9.65) = 2.90, p = 0.017, d = 1.29], with a trend for a decrease in AUC for candidates pre- to post-LAGB [t(10) = 2.07, p = 0.065, d = 0.811]. No significant differences for AUC for PYY were found between normal-weight controls and surgical candidates, or surgical candidates pre- to post-LAGB. Normal-weight controls and surgical candidates did not differ by AUC for any VAS rating; however, post-LAGB, adolescents reported a significantly greater AUC for nausea [t(10) = − 2.58, p=0.03]. Conclusions: Despite short-term decreases in body mass index post-LAGB, few changes were observed in appetitive hormones prior to or following a standardized breakfast. In addition, subjective ratings of fullness, hunger, nausea, and desire to eat did not differ between surgical candidates and normal-weight controls, but following LAGB, adolescents reported significantly more nausea. Future studies should examine longer-term effects of LAGB on appetitive hormones

Disordered eating following bariatric surgery: a review of measurement and conceptual considerations

Eating disorders are associated with significant medical morbidity and mortality and serious psychological impairment. Individuals seeking bariatric surgery represent a high-risk group for evidencing disordered eating and eating disorders, with some patients experiencing the persistence or onset of disordered eating postsurgery. This review synthesizes the available literature on problematic or disordered eating in the bariatric field, followed by a review of measurement and conceptual considerations related to the use of eating disorder assessment tools within the bariatric population