PharmacofMRI (Functional Magnetic Resonance Imaging) of Anxiolytic Medications (Alprazolam)

Phase 4

Completed

Interventions: Drug: 1.0 mg alprazolam
Drug: 0.25 mg alprazolam
Drug: placebo

Brief Summary: The purpose of this study is to use functional magnetic resonance imaging (fMRI) in healthy controls to examine the acute effects of certain anxiolytic medications on brain function.

Detailed Description: Increased amygdala and insula activity have been implicated in neurobiological models of anxiety. Using fMRI, the anxiolytic medication, lorazepam, has previously been found to decrease activation in these areas during the processing of emotional stimuli. This study aims to replicate those results but by using a different medication, alprazolam. An eventual aim of this study, in combination with future studies, is to evaluate the utility of fMRI as a tool to identify anxiolytic function in both established and novel compounds that may be used to treat anxiety.

Recruitment & Eligibility

Inclusion Criteria

Exclusion Criteria

Subjects with a history of DSM-IV depressive disorder, psychotic disorder, anxiety disorder
Subjects who meet criteria for substance abuse or dependence within the last 6 months
Subjects with an positive urine screen for illicit drugs
having clinically significant abnormal laboratory, ECG or physical examination findings not resolved by the baseline visit
Patients who have taken psychotropic drugs or antidepressants (including monoamine oxidase inhibitors, MAOI's) within the last year
subject is left-handed.
The subject suffers from claustrophobia, or phobia for injections or blood.
Magnetic Resonance Imaging related exclusion criteria: cardiac pacemaker, metal fragments in eyes/skin/body (shrapnel), subjects who have ever been a metal worker/welder; history of eye surgery/eyes washed out because of metal, aortic/aneurysm clips, prosthesis, by-pass surgery/coronary artery clips, hearing aid, heart valve replacement, subjects who are in the first trimester of pregnancy, subjects with an I.U.D. (birth control device), a shunt (ventricular or spinal), electrodes, metal plates/pins/screws/wires, or neuro/bio-stimulators (TENS unit).

Arm && Interventions

Group	Intervention	Description
2	1.0 mg alprazolam	1 mg alprazolam PO (liquid) will be administered 1 hour prior to fMRI scan One-time, single dose. Note that subjects receive all 3 treatments in randomized order (cross-over study), approximately 7-10 days apart.
1	0.25 mg alprazolam	0.25 mg alprazolam PO (liquid) will be administered 1 hour prior to fMRI scan. One-time, single dose. Note that subjects receive all 3 treatments in randomized order (cross-over study), approximately 7-10 days apart.
Placebo	placebo	Inactive ingredient in liquid matching appearance and volume of the two active alprazolam dose comparators. Note that subjects receive all 3 treatments in randomized order (cross-over study), approximately 7-10 days apart.

Primary Outcome Measures

Name	Time	Method
Effect of Alprazolam Versus Placebo on BOLD fMRI During Emotion Processing	Same Day	Analysis not completed.
Voxelwise Brain Imaging Data	Post-Rx Administration	Analysis of data not completed.

Secondary Outcome Measures