Bulimia nervosa is defined by recurrent episodes of binge eating followed by compensatory behaviors (such as induced vomiting) to prevent weight gain. It is a common and serious disease for which current treatment strategies have to be improved.

The aim of this study is to assess whether a transcranial magnetic stimulation reduces bulimic symptoms in a short term.

Repetitive Transcranial Magnetic Stimulation (rTMS) is a noninvasive outpatient technique of brain stimulation, based on the delivery of the localized magnetic field. It is now widely used a in a variety of neurological and psychiatric disorders.

Several clinical and pathophysiological studies suggest efficacy of rTMS on the reduction of craving and/or addictive behavior in various addictions such as alcoholism, smocking or cocaine. Because of the addictive design of the BN, the effect of one session of rTMS on food craving has been tested.

These studies show that stimulation of left dorsolateral prefrontal cortex (DPLPFC) under high frequency decreases craving food. In addition, in a healthy subject, studies show that rTMS appear to alter neuropsychological functions very involved in physiopathology of bulimia. To date, the investigators do not know if rTMS cold be a useful treatment in the treatment of bulimia. But in the light of these data, the investigators hypothesize that a program of rtMS may have a therapeutic effect and therefore an interest for the treatment of bulimia.

The objective of this project is to assess whether a program of repetitive transcranial magnetic stimulation (rTMS) under high frequency at the left DLPFC reduces bulimic symptoms in the short term.

This is a french multicenter study (Montpellier, Marseille, Saint Etienne), randomized, single blind, two arm, in addition of a treatment already validated (prescription of selective inhibitors of serotonin reuptake inhibitors (SSRIs)). The two arms are : one arm with SSRI + rTMS and an arm with SSRI + sham rTMS (placebo), 30 patients per group will be recruited.

The methodology includes:

1. an initial clinical and neuropsychological assessment.
2. 10 TMS sessions of 20 trains of 5s with 55s interval cross train, at a frequency of 10 Hz and 110% of motor threshold intensity of the left DLPFC. Fifty percent of patients will have a real stimulation and and the other fifty percent a sham stimulation. Subjects will be randomized to one or other of the two groups. During the first and last session a food challenge task will be administered before and after rTMS. Salivary cortisol level will be assessed throughout the protocol.
3. the final clinical and neuropsychological assessment at 1 month (15 days minimum after the last Session of rTMS).

The primary endpoint will focus on the number of binge within 15 days after the last session of rTMS.

If the investigators hypothesis is confirmed the investigators will highlight a new therapeutic modality in the treatment of bulimia. The secondary objectives will permit a better understanding of the pathophysiology of the disorder and ways of possible therapeutic actions of rTMS

Inclusion Criteria:

• Diagnostic of bulimia nervosa (DSM IV)
• Women (18-40 years old)
• right-handed
• treated by fluoxetine (60mg/j) or escitalopram (30mg/j) for at least 3 weeks.
• use effective contraceptive measures

Exclusion criteria:

• Current anorexia as DSM IV criteria
• Current psychiatric disorder unstabilized
• Taking corticosteroid
• History of seizures or epilepsy
• History of head trauma, cerebral pathology
• Serious physical illness unstabilized
• Prior use of the TMS
• pregnancy or breastfeeding
• Somatic disease may affect cognitive abilities and brain structures
• Loss of personal capacity resulting in state protection
• Deprivation of liberty by judicial or administrative decision
• Patients with pacemakers, defibrillator, neuro stimulator implanted.