Lisdexamfetamine for Adults With Bulimia Nervosa

The relatively high rates of bulimia nervosa (BN) in attention-deficit/hyperactivity disorder (ADHD) cohorts suggest a relationship between the two disorders. Interestingly, case studies involving this comorbid population have observed improvements in BN symptoms when given psychostimulants for ADHD. Case studies involving BN patents without this comorbidity have also demonstrated BN symptom improvements upon psychostimulant initiation. Recent studies have also found support for the use of lisdexamfetamine dimesylate, a psychostimulant approved for ADHD, for treating moderate to severe binge eating disorder, an eating disorder akin to BN. Given these findings, there is reason to believe that psychostimulants may also be capable of treating bulimia nervosa.

Ultimately, the investigators would like to conduct a large study that examines whether people who are diagnosed with BN will have fewer episodes of binge eating and purging when they are treated with the psychostimulant medication, lisdexamfetamine dimesylate (LDX). However, preliminary data would be helpful prior to undertaking such a large project. To this end, the aim of the current study is to learn more about a) enrolment rates, b) dropout rates, c) the applicability of our eligibility criteria, d) the potential effects of LDX on novel outcome measures for studying decision-making in BN, e) preliminary safety data, and f) estimates of treatment effect.

Participants (n = 30) will be instructed to take LDX once daily for two months while undergoing routine testing and monitoring to gather preliminary safety and treatment data. The research will take place at the Nova Scotia Health Authority Eating Disorder Clinic.


Eligibility Criteria:
Inclusion Criteria:

* 18-55 years of age and signed consent
* Diagnosis of moderate to extreme bulimia nervosa (4 or more episodes of compensatory behaviours per week).
* A body mass index (BMI) between 22 and 30 (calculated as kilograms per meters squared).
* Subject is consistently able to swallow a capsule
* If female, not breast feeding and not of child bearing potential (the latter defined as last menstruation at least 24 months prior to baseline, has undergone tubal ligation, and undergone hysterectomy)
* If female of childbearing potential, agree to use a reliable form of birth control and has a negative serum pregnancy test prior to medication initiation.

Exclusion Criteria:

* A comorbid bipolar disorder, psychotic disorder, moderate-severe depression, and/or ADHD using the SCID-4.
* Previous history of anorexia nervosa (e.g., due to the risk of problematic weight loss secondary to stimulant misuse).
* Severly restrictive eating behaviours, defined as routinely (\>2 days a week) eating less than 2 meals a day or at the investigator's discretion.
* Clinically meaningful abnormalities in laboratory tests or electrocardiography results (most relevant concerns include electrolyte abnormalities, hypoglycemia, prolonged QTc, hypertension, and tachycardia).
* Personal or family history of cardiovascular disease that could increase the vulnerability to the sympathomimetic effects of stimulants (e.g., structural cardiac abnormalities, cardiomyopathy, serious heart arrhythmia, advanced arteriosclerosis, or coronary artery disease) or any current symptomatic cardiovascular disease, as determined by the PI, and/or in consultation with cardiologist (as needed).
* Subject has moderate to severe hypertension (\>140/90 mmHg).
* Subject is receiving psychotherapy for the treatment of BN.
* Subject is taking or has taken a psychostimulant within the past 3 months.
* Subject is taking another psychotropic medication AND the dose has been changed 4 weeks prior to study medication initiation (e.g., baseline).
* Subject is on an antipsychotic medication (due to opposing mechanism of action).
* A suspected history of substance use disorder in the preceding 6 months or more distant (e.g., severe history of prior stimulant abuse) or a lifetime history of stimulant substance use disorder.
* Subject is taking or has taken a monoamine oxidase inhibitor (MAOI) within the last 14 days or has a hypersensitivity to amphetamine products or other ingredients in LDX.
* Subject is pregnant, plans to become pregnant, or is nursing.
* Subject uses syrup of ipecac to self-induce vomiting.
* Subject is considered a suicide risk.
* Subject has a known allergy to amphetamines, or other non-medical ingredients in LDX, or is sensitive to, is allergic to, or has had a reaction to other stimulant medications.
* Subject has been diagnosed with glaucoma (an eye disease).
* Subject has been diagnosed with hyperthyroidism (an overactive thyroid gland).
* Insufficient knowledge of English.