Novel treatment options of binge eating disorder

Pharmacological modulation of the endocannabinoid signalling alters binge-type eating behaviour in female rats

BACKGROUND AND PURPOSE

Binge eating disorder (BED) is characterized by excessive food intake during short periods of time. Recent evidence suggests that alterations in the endocannabinoid signalling could be involved in the pathophysiology of BED. In this study, we investigated whether pharmacological manipulation of endocannabinoid transmission may be effective in modulating the aberrant eating behaviour present in a validated rat model of BED.

EXPERIMENTAL APPROACH

Binge-type eating was induced in female rats by providing limited access to an optional source of dietary fat (margarine). Rats were divided into three groups, all with ad libitum access to chow and water: control (C), with no access to margarine; low restriction (LR), with 2 h margarine access 7 days a week; high restriction (HR), with 2 h margarine access 3 days a week.

KEY RESULTS

Compared with the LR group, the HR group consumed more margarine and this was accompanied by an increase in body weight. The cannabinoid CB₁/CB₂ receptor agonist Δ⁹-tetrahydrocannabinol significantly increased margarine intake selectively in LR rats, while the fatty acid amide hydrolase inhibitor URB597 showed no effect. The CB₁ receptor inverse agonist/antagonist rimonabant dose-dependently reduced margarine intake in HR rats. Notably, in HR rats, chronic treatment with a low dose of rimonabant induced a selective long-lasting reduction in margarine intake that did not develop tolerance, and a significant and persistent reduction in body weight.

CONCLUSIONS AND IMPLICATIONS

Chronic pharmacological blockade of CB₁ receptors reduces binge eating behaviour in female rats and may prove effective in treating BED, with an associated significant reduction in body weight.

Therapeutic options for binge eating disorder

OBJECTIVE

This article addresses the state of the art concerning the treatment of binge eating disorder (BED). Pharmacological and psychotherapeutic strategies, together with issues concerning the involvement in bariatric surgery are considered.

METHOD

A Medline enquiry of published articles was performed using the following keywords: BED, pharmacological treatment, duloxetine, venlafaxine, SSRI, psychotherapy, bariatric surgery; reviews and single-case studies were also analyzed.

RESULTS

Psychological interventions that have shown efficacy in the treatment of Bulimia Nervosa have also been tested in BED with positive results, in particular modified cognitive behavioral therapy, interpersonal therapy and dialectical behavior therapy. In addition pharmacotherapy with SSRIs is successful in transiently reducing binge-eating and body weight; the SNRI duloxetine is effective for reducing binge eating, and global severity of illness with a controversial effect on body weight; both topiramate and sibutramine seem promising, but their use is restricted due to labeling and side effect limitations, respectively. Finally, adequate psychological/pharmacological support can help BED patients obtain positive outcomes from bariatric surgery.

CONCLUSION

Studies on BED treatment are burdened by several limitations as selection biases (e.g. mostly women and overweight), small samples, high drop-out rates and placebo response.