Behavioral Consequences of Blunting Fear with Acetaminophen

The widely used painkiller acetaminophen (also known as paracetamol) has been found to blunt various emotional states and evaluations, possibly through the same mechanisms by which it dulls the affective component of physical pain. However, there are limited investigations into the behavioral consequences of blunting emotions pharmacologically. Previous work has demonstrated that acetaminophen lessens risk perception and increases risk-taking in tasks with low-stakes incentives, though no studies have tested its effects in fear-inducing contexts that require evaluating safety risk. As fear promotes behaviors that keep us safe, dampening fear could alter how people respond to threatening situations. To test this possibility, 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 took less time to step onto the plank, walked across it faster, and had lower heart rates. These findings suggest that acetaminophen may reduce protective behaviors associated with the fear response, raising potential safety concerns for everyday users.