Katherine Presnell

DISSONANCE AND HEALTHY WEIGHT EATING DISORDER PREVENTION PROGRAMS: LONG-TERM EFFECTS FROM A RANDOMIZED EFFICACY TRIAL

Adolescent girls with body dissatisfaction (N = 481, SD = 1.4) were randomized to a dissonance-based thin-ideal internalization reduction program, healthy weight control program, expressive writing control condition, or assessment-only control condition. Dissonance participants showed significantly greater decreases in thin-ideal internalization, body dissatisfaction, negative affect, eating disorder symptoms, and psychosocial impairment and lower risk for eating pathology onset through 2- to 3-year follow-up than did assessment-only controls. Dissonance participants showed greater decreases in thin-ideal internalization, body dissatisfaction, and psychosocial impairment than did expressive writing controls. Healthy weight participants showed greater decreases in thin-ideal internalization, body dissatisfaction, negative affect, eating disorder symptoms, and psychosocial impairment; less increases in weight; and lower risk for eating pathology and obesity onset through 2- to 3-year follow-up than did assessment-only controls. Healthy weight participants showed greater decreases in thin-ideal internalization and weight than did expressive writing controls. Dissonance participants showed a 60% reduction in risk for eating pathology onset, and healthy weight participants showed a 61% reduction in risk for eating pathology onset and a 55% reduction in risk for obesity onset relative to assessment-only controls through 3-year follow-up, implying that the effects are clinically important and enduring.

Testing Mediators of Intervention Effects in Randomized Controlled Trials: An Evaluation of Two Eating Disorder Prevention Programs.

The authors investigated mediators hypothesized to account for the effects of 2 eating disorder prevention programs using data from 355 adolescent girls who were randomized to a dissonance or a healthy weight intervention or an active control condition. The dissonance intervention produced significant reductions in outcomes (body dissatisfaction, dieting, negative affect, bulimic symptoms) and the mediator (thin-ideal internalization), change in the mediator correlated with change in outcomes and usually occurred before change in outcomes, and intervention effects became significantly weaker when change in the mediator was partialed, providing support for the hypothesized mediators and this new approach to testing mediation in randomized trials. Findings provide somewhat less support for the hypothesis that change in healthy eating and exercise would mediate the healthy weight intervention effects.

Depression and eating pathology: prospective reciprocal relations in adolescents.

The association between disordered eating and depression has been established, but less is known about the temporal relations between these two disturbances. Accordingly, the current study examined the reciprocal relations between depressive and bulimic symptoms over an 8-year period, with longitudinal data from a community sample of 496 female adolescents. Depressive symptoms predicted future increases in bulimic symptoms, and bulimic symptoms likewise predicted increases in depressive symptoms, controlling for earlier levels of symptoms for each outcome. These results provide evidence consistent with the hypothesis that the two disorders contribute reciprocally to each other, and indicate that successful prevention or treatment of one disorder may yield effects for the other. However, the relatively small predictive effect sizes imply that some third variable may contribute to both conditions (e.g., temperamental negative affectivity).

Sex differences in the relation of weight loss self-efficacy, binge eating, and depressive symptoms to weight loss success in a residential obesity treatment program.

The aim of the current study was to examine whether weight loss self-efficacy, binge eating, and depressive symptoms predicted weight loss during treatment, and whether gender moderates these associations with prospective data from 297 participants (223 women and 74 men) enrolled in a residential obesity treatment program. Men reported higher initial levels of self-efficacy than women, whereas women reported greater pre-treatment levels of binge eating and depressive symptoms. Higher pre-treatment levels of weight control self-efficacy, binge eating, and depressive symptoms predicted greater weight loss in men, but not in women. Results suggest that certain psychological and behavioral factors should be considered when implementing weight loss interventions, and indicate a need to consider gender differences in predictors of weight loss treatment. Future research should seek to identify predictors of weight loss among women.

An investigation of the relationship between fear of negative evaluation and bulimic psychopathology.

The current study examined fear of negative evaluation (FNE), the core fear associated with social anxiety, in the context of the dual pathway model of the etiology of bulimia nervosa. Our primary aim was to improve the understanding of the development of bulimic psychopathology. We investigated the relationships between FNE, the risk factors of the dual pathway model and bulimic symptoms using path analysis in a sample of female undergraduates (N=210). The inclusion of FNE increased the predictive ability of the model to account for 49% of the variance in bulimic symptoms compared to previous findings in which the model accounted for 33% of the variance. Additionally, FNE was related to several risk factors of the dual pathway model including the pressure to be thin, thin-ideal internalization and negative affect, as well as contributing directly to bulimic symptoms. These findings suggest that FNE may increase the risk for developing established risk factors of the model, as well as bulimic symptoms, and that targeting FNE in prevention programs may be useful in circumventing this serious disorder.

Physical activity as a moderator of the association between anxiety sensitivity and binge eating

Individuals with elevated anxiety sensitivity (AS; i.e., fear of somatic arousal) may binge eat to reduce emotional distress. Because physical activity reduces stress reactivity, we predicted that: (1) the relation between AS and binge eating would be moderated by physical activity and (2) coping motives for eating would mediate the association between AS and binge eating such that the relation would be stronger for those low in physical activity. Participants (N=167) completed online self-report measures. Regression analyses revealed that moderate-intensity physical activity (MPA) moderated the relation between AS and binge eating such that AS was not related to binge eating among those who frequently engaged in MPA but was related to binge eating among those who did not report engaging in MPA. Vigorous-intensity physical activity (VPA) moderated in the opposite direction such that the relation between AS and binge eating was significant among persons reporting high levels of VPA but less strong among persons reporting low levels of VPA. The mediation model was also significant, but was not moderated by MPA or VPA. Theoretical and clinical implications are discussed.

Experimental investigation of the effects of naturalistic dieting on bulimic symptoms: moderating effects of depressive symptoms.

Prospective studies suggest that dieting increases risk for bulimic symptoms, but experimental trials indicate dieting reduces bulimic symptoms. However, these experiments may be unrepresentative of real-world weight loss dieting. In addition, the fact that most dieters do not develop eating disorders suggests moderating factors may be important. Accordingly, we randomly assigned 157 female intermittent dieters to either diet as they usually do for weight loss or eat as they normally do when not dieting for 4 weeks. Naturalistic dieting halted the weight gain shown by controls, but did not result in significant weight loss. Although there was no main effect of the dieting manipulation on bulimic symptoms, moderation analyses indicated that naturalistic dieting decreased bulimic symptoms among participants with initially low depressive symptoms. Results suggest that self-initiated weight loss dieting is not particularly effective, which appears to explain several discrepancies in the literature. Additionally, depressive symptoms may be an important determinant of bulimic symptoms that eclipses the effects of naturalistic dieting on this outcome.

Psychological variables impacting weight gain rapidity in adolescents hospitalized for eating disorders.

OBJECTIVE This prospective study examined whether psychological variables related to the transdiagnostic theory of eating disorders measured at admission predicted length of time to reach 85 per cent of ideal body weight (IBW) among underweight adolescents hospitalized for an eating disorder. METHOD Thirty-three girls (aged 12-17) weighing below 85 per cent of IBW, admitted to an inpatient and/or partial hospitalization eating disorder programme completed self-report measures at admission. Cox regression tested whether scores on admission measures predicted time to reach 85 per cent of IBW. RESULTS After controlling for IBW at admission, higher self-esteem and lower perfectionism predicted shorter time to reach 85 per cent of IBW, with emotion regulation as a marginally significant predictor. CONCLUSION Self-esteem and perfectionism may be predictors of responsiveness to weight-gain efforts during hospitalization. Further studies are necessary to determine whether these variables might be appropriate targets for intervention to promote weight gain in underweight girls with eating disorders.

Distributed and condensed versions of a cognitive dissonance programme: comparative effects on eating disorder risk factors and symptoms

Research regarding different learning schedules is equivocal. Learning theory suggests that distributed learning may better facilitate long-term maintenance of behaviour change [Bouton, M. (2000). A learning theory perspective on lapse, relapse, and the maintenance of behavior change. Health Psychology: Special Issue: Maintenance of Behavior Change in Cardiorespiratory Risk Reduction, 19, 57–63]. Alternatively, some research suggests that massed-intensive content delivery can be as beneficial as distributed delivery [e.g. Rogojanski, J., & Rego, S. A. (2013). Advances and controversies in the application of a modified version of cognitive behavior therapy for social anxiety disorder. Pragmatic Case Studies in Psychotherapy, 9(3), 337–346]. The present study compared two versions of a cognitive dissonance (CD)-based eating disorders (EDs) prevention programme. CD interventions target ED risk factors via an interactive format with content spread over multiple sessions, and have demonstrated both efficacy and effectiveness across numerous trials. We randomised female undergraduates (N = 73) to either four 1-hour sessions over four weeks (4SV), or two 2-hour sessions over two weeks (2SV). The versions were identical in content and total intervention time. Results indicated that both conditions showed similar rates of improvement in ED risk factors and symptoms through a 12-month follow-up, with the exception of thin-ideal internalisation, where results suggested a possible advantage of the 4SV for long-term, but not short-term, gain. Therefore, findings suggest that entities implementing CD are able to select the format that best fits their needs without significantly compromising the positive impact of the programme. Implications regarding the dissemination benefits of a flexible programme format that maintains effectiveness are discussed.