The study uses neurobiological measures through brain imaging, neuropsychological measures, and selfreport measures to try to understand how an effective treatment for alcoholism works. On the whole, less than 50% of people with alcoholism get better with treatment. This study will help researchers develop better treatments for alcoholism because if the investigators know why the treatments the investigators use are working, and in whom the treatments work best, then the investigators may be able to make treatment more effective by targeting treatments to individuals who would be most likely to benefit and by guiding development of more effective treatments in the future.

Inclusion Criteria:

1. Males and females age 18-65 meeting DSM-IV criteria for alcohol dependence in the past year;
2. seeking but not currently receiving treatment;
3. able to provide voluntary informed consent;
4. have at least 4 drinking days in the past 30 days
5. english-speaking
6. have a primary care physician or psychiatrist willing to continue prazosin if the patient tolerates it well and is finding it beneficial.

Exclusion Criteria:

1. severe neurological (e.g., head injury/stroke) conditions, Meniere's disease, narcolepsy, benign positional vertigo, heart disease or unstable angina, history of dysrhythmia/syncope, SBP<110, SBP>160, DBP>110, HR<55, HR>110, irregular heart rhythm, chronic renal or hepatic failure, pancreatitis or insulin-dependent diabetes, or other medical problems requiring immediate attention;
2. schizophrenia, schizoaffective disorder, PTSD, Bipolar I disorder, suicidal thoughts within the last month;
3. current dependence on another drug of abuse (except nicotine);
4. contraindications to MRI (e.g., pacemaker);
5. active legal problems with the potential to result in incarceration;
6. pregnancy or lactation, or child bearing age and not on birth control;
7. currently receiving treatment for alcohol dependence;
8. current use of psychoactive medications including SSRI's and other antidepressants, anti-craving medications, anxiolytics including benzodiazepines, antipsychotics, mood stabilizers or anticonvulsants;
9. history of seizures or DT's during alcohol withdrawal.