Acetaminophen (paracetamol) can blunt various emotional states and evaluations, seemingly through the same mechanisms by which it dulls the affective component of physical pain. However, most of this work has used self-report or neural measures, with more limited investigations into behavioral effects of blunting emotions pharmacologically. As emotions influence behavior in ways that are adaptive on average, interfering with them might lead to unwanted behavioral changes. For example, disrupting the affective processing of a scary situation might lead individuals to react to it less cautiously. 260 participants were given either 1000 mg of acetaminophen or placebo capsules prior to a frightening virtual reality plank walk at extreme heights. Compared to the placebo group, those on acetaminophen stepped onto the plank sooner, walked across it faster, and had lower heart rates. These findings suggest that acetaminophen might reduce cautious behaviors in dangerous situations, but could also be potentially useful in clinical settings where overly cautious and avoidant behaviors are disproportionate to the danger posed.
