Progesterone and Brain Imaging Study

Multimodal Imaging of Progesterone/Neurosteroid Effects in Nicotine Addiction

Male and female smokers were recruited to undergo 2 phases of smoking cessation. Each phase was 4 days long and involved 3 brain-imaging scans, blood draws and an intervention involving progesterone or a matched placebo.

The purpose of this study is to learn whether a sex hormone called progesterone is helpful in reducing cigarette smoking and craving for cigarettes. This study also includes brain imaging to measure possible effects of progesterone on certain neurochemicals. These neurochemicals are called gamma-aminobutyric acid (or GABA for short) and glutamate. Both nicotine and progesterone affect these brain chemicals.

Individuals wishing to participate in this study must be medically healthy men or women who smoke at least 10 cigarettes per day or greater. Participants must not suffer from a mental illness or use drugs other than nicotine and marijuana. Participants cannot have any implanted metallic devices such as pacemakers, orthodontic braces, or shrapnel. Participants must not have peanut allergies and must never have had a reaction to progesterone. Finally, participants cannot be taking any medications for anxiety, depression or insomnia.

Inclusion Criteria:

• Female and male smokers, aged 18 to 50 years;
• History of smoking greater than or equal to 10 cigarettes daily for the past year, as per self-report (periods of smoking abstinence within the last year will be exclusionary at PI discretion);
• Not seeking treatment at the time of the study for nicotine dependence;
• Have a Fagerstrom Test for Nicotine Dependence (FTND) score of at least 3 and a Carbon Monoxide (CO) level greater than or equal to 11 ppm;
• Clean urine drug screen (marijuana is permissible);
• In good health as verified by medical history;
• For women, not pregnant as determined by pregnancy screening, nor breast feeding.

Exclusion Criteria:

• History of major medical illness: including liver diseases, abnormal vaginal bleeding, suspected or known malignancy; thrombophlebitis; deep vein thrombosis; pulmonary embolus; clotting or bleeding disorders; heart disease; diabetes; history of stroke or other medical conditions that the physician investigator deems as contraindicated for the patient to be in the study;
• Regular use of psychotropic medication (antidepressants, antipsychotics, or anxiolytics) and recent (within previous year) psychiatric diagnosis and treatment for Axis I disorders including major depression, bipolar affective disorder, generalized anxiety disorder, post-traumatic stress disorder and panic disorder;
• Lifetime history of schizophrenia or other psychotic disorder;
• Lifetime substance dependence disorder, excepting nicotine, alcohol and marijuana, as per SCID interview
• Substance use disorders within the previous 2 years, excepting nicotine, as per SCID interview
• Regular use of any other tobacco products than cigarettes, including smokeless tobacco and nicotine products;
• Known allergy to progesterone or peanuts (vehicle for micronized progesterone).