Pilot Study Repetitive Transcranial Magnetic Stimulation (rTMS) in Cannabis Craving

-INCLUSION CRITERIA:

i) Eighteen to sixty-five years of age

ii) Cannabis user for at least 2 years, currently averaging 3 times weekly

iii) Reading level of at least 6th grade, based on the Wide Range Achievement Test (WRAT)

iv) Ability to give valid informed consent

v) Right-handed

vi) If the subject is female, of childbearing potential, and sexually active, she agrees to use a medically acceptable form of contraception, and not become pregnant for the duration of the study. A woman is considered of childbearing potential unless post-menopausal or surgically sterilized. Female patients of childbearing potential who are or who anticipate the possibility of becoming sexually active with a male partner must use either: (1) contraceptive pill or IUD or depot hormonal preparation (ring, injection, implant); and/or (2) a barrier method of contraception such as diaphragm, sponge with spermicide, or condom. Women who are not sexually active do not have to agree to use one of the acceptable contraception methods. Contraceptive measures will be reviewed with female subjects at each visit prior to the rTMS treatment

vii) Self-report experiencing cannabis craving when exposed to cannabis-associated cues

EXCLUSION CRITERIA:

i) Personal or first-degree family history of any clinically defined neurological disorder, including organic brain disease, epilepsy, stroke, brain lesions, multiple sclerosis, previous neurosurgery, or personal history of head trauma that resulted in loss of consciousness.

ii) Cardiac pacemakers, neural stimulators, implantable defibrillator, implanted medication pumps, intracardiac lines, or acute, unstable cardiac disease, with intracranial implants (e.g. aneurysm clips, shunts, stimulators, cochlear implants, or electrodes) or any other metal object within or near the head that cannot be safely removed.

iii) Metal shrapnel or bullet in the head or body including metal shavings.

iv) Current use of any investigational drug or of any medications with anti or pro-convulsive action

v) Increased intracranial pressure (lowers seizure threshold)

vi) Lifetime history of major depressive disorder, schizophrenia, bipolar disorder, mania, or hypomania

vii) History of myocardial infarction, angina, congestive heart failure, cardiomyopathy, stroke or transient ischemic attack, or any heart condition currently under medical care.

viii) Pregnant or nursing women or women with reproductive potential not using an acceptable form of contraception.

ix) Any history of seizure

x) Current dependence (DSM-IV criteria) on substances other than cannabis or nicotine.

xi) Claustrophobia making them unable to tolerate lying in the MRI scanner