Smoked Nicotine Induced Changes in Hormone Function, Mood States and Behaviors

Inclusion Criteria: * Women between the ages of 18 and 40 who currently smoke at least 15 cigarettes every day, and who fulfill DSM-IV diagnostic criteria for nicotine dependence (305.10) will be eligible for participation. * No evidence of clinically significant disease based upon complete medical history and physical examination by a qualified physician. * Absence of DSM-IV Axis I Disorders other than nicotine dependence (305.10) as measured by the Structured Clinical Interview (SCID). * Routine laboratory blood tests including complete blood count, electrolytes, BUN and creatinine, liver function test, hepatitis panel and urinalysis will be performed. Laboratory parameters must be within the normal range. HBsAg must be negative but participants who have hepatitis serology consistent with previous exposure to Hepatitis A, Hepatitis B, or Hepatitis C, but who do not have clinical and biochemical evidence of acute infection, will be acceptable. * Hematocrit levels ≥ 35%. * Serum pregnancy test (hCG beta subunit) results must be negative within 24 hrs of the study session day. * Normal ECG. * A mean Body Mass Index (ratio of weight (W) to height (H) squared; W/H2=kg/m2) will be calculated. Men with a mean Body Mass Index between 21.4-29.0 and women with a mean Body Mass Index (BMI) between 18.0-27.0 will be accepted. * Participants must be able to read, understand instructions and provide a valid informed consent. Exclusion Criteria: * Women with any lifetime DSM-IV Axis I disorder other than nicotine dependence will be excluded. * Women who are pregnant as determined by laboratory testing for serum beta hCG will be excluded. * Women who use hormonal contraceptive medications will not be accepted for participation because this would confound the hormonal measures. * Women with clinically significant medical disorders will be excluded. * A mean Body Mass Index (ratio of weight (W) to height (H) squared; W/H2=kg/m2) will be calculated. Women with a mean Body Mass Index (BMI) outside of the range of 18.0-27.0 will be excluded. * Treatment seeking participants will not be selected but will be referred to local smoking cessation programs. * Women taking any OTC on a regular basis (with the exception of multivitamin formulas) or prescription medications will be excluded. * Women with a blood pressure below 90/60 will be excluded.