Objective: Self-medication is promoted to extend healthy life expectancy. Accordingly, it is important for general consumers to properly use over-the-counter drugs. We investigated whether graphical symbols to visually aid the understanding of drug information (i.e., precautions and instructions to consult with a medical professional) provided in over-the-counter drug package inserts are easily understood in light of the International Organization for Standardization (ISO) criterion of 66％ comprehension. Methods: First, two questionnaire surveys were conducted with pharmacy students to calculate their comprehension level of the illustrations. The first round was for modifying illustrations that did not meet the ISO standard, and the second round was for seeing if comprehension had improved. Then, a questionnaire survey targeting general consumers was conducted to see if these illustrations functioned as graphical symbols. Results: When the referent of “Do not take this medicine if your experience falls under the following conditions” was placed in the upper left corner of the symbol, some students answered that this meant, “If you do not take this medicine, you will be under the following conditions,” but when it was placed in the lower right corner, many students accurately understood the intended information. In the student surveys, one illustration each for “cannot be taken/under treatment/heart,” “cannot be taken/under treatment/stomach,” “cannot be taken/under treatment/liver,” and “cannot be taken/under treatment/kidney” all exceeded 66％. Since none of the illustrations exceeded the 66％ comprehension in the survey of general consumers, it was found to be difficult for general consumers to understand drug information from the present illustrations. However, there were several illustrations that improved in comprehension compared to the previous study, which makes the continuation of this study significant. Conclusion: Although there were no illustrations exceeded 66％ comprehension of general consumers, the study shows that continued improvement may result in establishing pictograms for general consumers.

Objective: The placebo effect can enhance the response to treatment, even in the absence of pharmacological ingredients. One possible factor explaining the likelihood of the placebo effect in individuals is genetic polymorphisms in neurotransmitters. This study focused on gene polymorphisms in the catechol-O-methyltransferase (COMT) as an interindividual variable of the placebo effect.Design・Methods: All 120 participants were explained the effects of caffeine, including its ability to ameliorate drowsiness and increase concentration, and then given a placebo (lactose). The onset of the placebo effect was measured in terms of the degree of caffeine-reduced sleepiness using subjective indices of the Stanford Sleepiness Scale (SSS) and a feeling of drowsiness-Visual Analogue Scale (VAS). The mechanism of the placebo effect was objectively examined in terms of changes in cerebral blood flow in the prefrontal cortex of the brain. In addition, we investigated participants’ susceptibility to the placebo effect by examining genetic polymorphisms in COMT.Results: After taking the drug, sleepiness on the SSS and VAS was significantly improved (p＜0.001), although there was no change in prefrontal cortex activity. Among the 120 participants, 63 had a Val/Val-type polymorphism in COMT (52.5%), 45 had a Val/Met-type (37.5%), and 12 had a Met/Met-type (10.0%). There were no significant differences among COMT gene polymorphisms in the subjective measures of SSS and VAS. However, there was a tendency for the cerebral blood flow changes to be larger in the left hemisphere of the brain in individuals with the Met/Met type.Conclusion: There seems to be a relationship between prefrontal cortex activity and genetic polymorphisms. In particular, there may be a correlation between the expression of a placebo effect and COMT gene polymorphisms.