MedicalResearch.com Interview with: Alexander Stridh, MSc Department of Clinical Neuroscience Karolinska Institute Solna, Sweden MedicalResearch.com: What is the background for this study? What are the main findings? Response: ​We wanted to investigate how large the effect size is in the placebo arm of clinical trials with PDE5Is for erectile dysfunction. The major findings in this study is that there is a placebo response in general in ED, though it is hard to tell if this is a genuine placebo effect rather than normal fluctuations in symptom severity among patients. Another interesting finding was that the placebo response seems largely more important when the cause of ED is mainly due to psychogenic factors, as in post traumatic stress disorder. Lastly there was an important finding that there was no difference between placebo and active drug with daily treatment of PDE5Is  for long term recovery of erectile function after prostate cancer treatment, a practice which is common in some places and seems to be questionable.  (more…)