Effect of Nicotine on Brain Reward Pathways

Inclusion criteria

for subjects with Major Depressive Disorder:

• Provide written informed consent;
• Both genders and all ethnic origins, age between 18 and 45;
• Meet DSM-IV diagnostic criteria for MDD (diagnosed with the use of the SCID);
• A baseline HAM-D score of 16 or greater;
• Absence of pregnancy;
• Absence of any psychotropic medication for at least 2 weeks:

• 6 weeks for fluoxetine
• 6 months for neuroleptics
• 2 weeks for benzodiazepines
• 2 weeks for any other antidepressants

Inclusion criteria

for Healthy Controls

• Absence of medical, neurological, and psychiatric illness (including alcohol and substance abuse); as assessed by subject history and a structured clinical interview (SCID);
• Provide written informed consent;
• Both genders and all ethnic origins, age between 18 and 45;
• Absence of any medications for at least 3 weeks;
• Absence of pregnancy.

Exclusion criteria

• Subjects with suicidal ideation where outpatient treatment is determined unsafe. These patients will be immediately referred to a licensed psychologist or psychiatrist to determine the appropriate clinical treatment;
• Serious or unstable medical illness
• Lifetime history of seizure disorder;
• Lifetime history or current diagnosis of any of the following DSM-IV psychiatric illnesses: organic mental disorder, schizophrenia, schizoaffective disorder, delusional disorder, psychotic disorders not otherwise specified, bipolar disorder, ADHD, patients with mood congruent or mood incongruent psychotic features; simple phobia, social anxiety disorder and generalized anxiety disorders will be allowed only if secondary to MDD;
• Patients with a lifetime history of electroconvulsive therapy (ECT);
• Failure to meet standard MRI safety requirements;
• May not have used any nicotine product in the past year; must report fewer than 20 lifetime uses of nicotine
• Must have an expired carbon monoxide level of less than or equal to 10 ppm.
• Use of anticholinergic drugs in the past week
• Any past or present history of cardiac problems including known arrhythmias, acute coronary syndrome, or ischemic heart disease
• Uncontrolled hypertension
• History of substance abuse in the past 6 months (other than caffeine), self-reported use of marijuana in past month, or history of treatment with methadone
• Heavy caffeine users (consume greater than 500 mg on a regular or daily basis)
• Subjects that cannot speak English