A new study undertaken by researchers at Ohio State University finds that acetaminophen use appears to diminish the intensity of positive emotions, a previously undetected side effect of the medication. The results are reported online in the journal Psychological Science. Previous research had shown that acetaminophen works not only on physical pain, but also on psychological pain. This study takes those results one step further by showing that it also reduces how much users actually feel positive emotions, although the affected individuals did not appear to be aware of the impact.
In one study involving 82 participants, half took an acute dose of 1000 milligrams of acetaminophen and half who took an identical-looking placebo. Participants were then asked to rate their reactions to a series of photographs depicting positive, neutral, or negative scenes. Those subjects who took acetaminophen rated all the photographs, both positive and negative, less extremely than did those who took the placebo. At this point, the researchers don’t know if other pain relievers such as ibuprofen and aspirin have the same effect, although they plan on studying that question.
Read a news story about the research findings here.