Losartan and Emotional Learning

This study examines whether a blood pressure drug called losartan affects emotional learning and memory — specifically how people learn and unlearn fear or reward associations. Losartan blocks a hormone called angiotensin II, which may influence memory circuits in the brain. **You may be eligible if...** - You are between 18 and 50 years old - You have low to moderate anhedonia (reduced ability to feel pleasure, assessed by questionnaire) - You speak and read English well enough to complete the study tasks - You are a non-smoker or light smoker (fewer than 5 cigarettes per day) **You may NOT be eligible if...** - You have (or have had) a psychiatric diagnosis other than anxiety, dysthymia, or unipolar depression - You have taken any CNS medications in the past 6 weeks - You are currently on blood pressure medication, especially aliskiren or beta-blockers - You have a first-degree family member with severe psychiatric illness Talk to your doctor to see if this trial is right for you.