Over-the-Counter Relief From Pains and Pleasures Alike: Acetaminophen Blunts Evaluation Sensitivity to Both Negative and Positive Stimuli

• Published in: Psychological science Vol. 26; no. 6; pp. 750 - 758
• Main Authors: Durso, Geoffrey R. O., Luttrell, Andrew, Way, Baldwin M.
• Format: Journal Article
• Language: English
• Published: Los Angeles, CA SAGE Publications 01.06.2015; SAGE PUBLICATIONS, INC
• Subjects: Acetaminophen - adverse effects; Affect - drug effects; Analgesics; Analgesics, Non-Narcotic - adverse effects; Arousal - drug effects; Attitudes; Emotions; Evaluation; Humans; Medical research; Medical treatment; Medicine; Nonprescription Drugs; Pain; Pain - drug therapy; Pain management; Photic Stimulation; Pleasure - drug effects; Psychology; Visual Perception; evaluation; acetaminophen; differential susceptibility; emotion; attitudes; affect
• ISSN: 0956-7976; 1467-9280
• DOI: 10.1177/0956797615570366

Acetaminophen, an effective and popular over-the-counter pain reliever (e.g., the active ingredient in Tylenol), has recently been shown to blunt individuals' reactivity to a range of negative stimuli in addition to physical pain. Because accumulating research has shown that individuals' reactivity to both negative and positive stimuli can be influenced by a single factor (an idea known as differential susceptibility), we conducted two experiments testing whether acetaminophen blunted individuals' evaluations of and emotional reactions to both negative and positive images from the International Affective Picture System. Participants who took acetaminophen evaluated unpleasant stimuli less negatively and pleasant stimuli less positively, compared with participants who took a placebo. Participants in the acetaminophen condition also rated both negative and positive stimuli as less emotionally arousing than did participants in the placebo condition (Studies 1 and 2), whereas nonevaluative ratings (extent of color saturation in each image; Study 2) were not affected by drug condition. These findings suggest that acetaminophen has a general blunting effect on individuals' evaluative and emotional processing, irrespective of negative or positive valence.