Scientists test how your daily pills might change your mind

This research study aimed to understand how everyday over-the-counter and prescription medications might influence a person's mood and their preference for taking certain drugs. Healthy adult volunteers took capsules containing substances like caffeine or nicotine (or a placebo) in a blind test over several weeks. Researchers measured how much participants liked the effects and what value they placed on the experience, to learn about factors that might relate to substance use.