Erectile performance anxiety (EPA) is a subset of sexual anxiety characterized by a fear of erectile failure. EPA has been shown to play a pivotal role in male sexual problems including premature ejaculation and erectile dysfunction (Loudon, 1998; Perelman, 2006). EPA affects approximately 14% to 23% of U.S. men across age groups (Laumann, Paik, & Rosen, 1999), and is the most common proximal cause of psychogenic ED (Hale & Strassberg, 1990; Hedon, 2003; Perelman, 1994; Rosen, 2001). Phosphodiesterase type 5 (PDE5) inhibitors such as sildenafil citrate (brand-name Viagra) are the first line of pharmacological treatment for ED. Recreational use of PDE5 inhibitors -- defined as unprescribed use with the goal of sexual enhancement and prevention of erectile failure among men without clinically significant erectile difficulties. Approximately 13.4% of young men between the ages of 18 - 30 report using PDE5 inhibitors recreationally. The most commonly reported reason for off-prescription use is to enhance one's sexual performance, i.e., longer lasting erections or impress one's sexual partner (Bechara, Casabe, De Bonis, Helien, & Bertolino, 2010; Harte & Meston, 2011; Holt, 2009; Korkes, Costa-Matos, Gasperini, Reginato, & Perez, 2008; Musacchio, Hartrich, & Garofalo, 2006). Reducing anxiety -- specifically EPA is often given as a reason for recreational use, though to a lesser extent (Korkes et al., 2008; Schnetzler, Banks, Kirby, Zou, & Symonds, 2010). However, PDE5 inhibitors do not exert a significant increase in penile tumescence among men without erectile dysfunction (Mondaini et al., 2008). The actual sexual enhancement from recreational use of PDE5 inhibitors among this population would be limited in that blood flow to the healthy erectile tissue is already optimal. The proposed study aimed to examine the effects of an erection-enhancing pill description misattribution on anticipatory anxiety and subsequent subjective and physiological sexual response to an audiovisual erotic stimulus. Participants underwent two assessments of their subjective and physiological arousal response to an erotic film after randomization to one of three conditions (erection-enhancing pill description, memory-enhancing pill description, or a no pill control). It was hypothesized that compared to those in the memory-enhancing pill group and the no pill control group, participants in the erection-enhancing pill group would respond with greater anticipatory anxiety and dampened penile tumescence in response to a subsequent no-pill erotic film presentation. Results of the study provided partial support for the hypothesized negative effects of the pill attribution manipulation. In the subset of subjects with complete pre and post-manipulation physiological data, those led to believe they ingested an erectile-enhancing herb showed a dampening of erectile tumescence to a subsequent erotic film presentation. Also, consistent with prediction, erectile performance anxiety was associated with decreased tumescence after the bogus "average" erectile performance feedback compared to baseline. These findings suggest that pill attribution may influence sexual arousal to some extent, despite methodological issues such as partial physiological data loss and believability of the pill instructional set manipulation. / text