The proposed study will test the effects of a fast-acting testosterone nasal spray on the fear reactions of young men to two distinct anxiety challenges (social and nonsocial) using a double-blind randomized experimental design.

Aim 1: Test the hypothesis that men administered testosterone nasal spray will result in lower levels of anxiety (anticipatory and situational) and greater levels of approach behavior in response to two distinct (social and nonsocial) anxiety challenges relative to men administered placebo spray.

Aim 2: Test the hypothesis that anxiety challenge type (social versus nonsocial) will moderate the effects of testosterone administration on subjects' responses to challenge.

Aim 3: Test the hypothesis that rejection sensitivity - heightened sensitivity to evaluative threat - will moderate the effects of drug condition on response to the two anxiety challenge tests.

Inclusion Criteria:

• Male, 18 years of age or older

Exclusion Criteria:

• Male breast cancer
• Obstructive sleep apnea
• Suspected or diagnosed prostate cancer
• Male breast cancer
• Obstructive sleep apnea
• Diabetes
• Heart Disease
• Liver disease (e.g., hepatitis)
• Kidney disease
• Thyroid disease
• Tuberculosis or history if positive TB test
• Infection or fever in the past 7 days
• Surgeries within the last 6 weeks
• Anemia
• Gastrointestinal disease
• Respiratory disease (e.g., asthma or chronic bronchitis)
• Other (Please list)
• Reynaud's Disease
• Type 2 diabetes
• Diagnosed hypersensitivity to cold
• Warfarin (Coumadin) for thinning blood
• Insulin or any oral drugs for diabetes
• Propranolol (Inderal)
• Oxyphenbutazone
• Imipramine
• Any kind of corticosteroid drug
• Insulin
• Steroids
• Statins (i.e.., cholesterol lowering drugs)
• Sleeping pills
• Drugs to treat hormone disorders
• Antibiotics in the past 7 days
• Gastrointestinal disease
• Pain Killers -