This study investigates the effects of repeated NAC administration on glutamate concentrations in the anterior cingulate cortex (ACC), on neurocognitive functioning, and on neuro-inflammatory parameters in adult cannabis-dependent individuals.

Inclusion Criteria:

• Current DSM-IV diagnosis of cannabis dependence, >1 week detoxified and abstinent;
• Able to provide written informed consent and to comply with study procedures.
• Dutch speaking (Dutch as primary language).

Exclusion Criteria:

• Currently dependent on any substance other than cannabis, alcohol or nicotine;
• History of any major internal disease (including diabetes, cardiovascular disease, lung disease, liver or kidney disease);
• An active or any history of neurological disorder, including but not limited to seizure disorder, epilepsy, stroke, neurological disease, cognitive impairment, head trauma with prolonged loss of consciousness (>10 minutes), or migraine headaches;
• An active or a history of a psychiatric disorder including, but not limited to, depression, schizophrenia, bipolar disorder, anxiety, or other psychiatric disorders;
• Asthma;
• Known hypersensitivity or allergy to n-acetylcysteine, or receiving chronic therapy with medication that could interact adversely with n-acetylcysteine within 30 days prior to randomization (i.e., nitroglycerin, ACE inhibitors or antihypertensive drugs, anti-coagulants);
• Exclusion criteria for MRI: having metal in the body and/or having claustrophobia