Before the invention of Viagra, a blockbuster erectile dysfunction (ED) drug, it was believed that men experience poor erection due to psychological issues.

And that might still be true for some men with ED caused by psychological issues, even in the era of Viagra and Cialis.

A new study, published online in JAMA Network Open, has found that a significant number of men who received a placebo in clinical trials for ED had an improvement in their erectile function.

Researchers found that the placebo effect was more pronounced in those who had ED due to post-traumatic stress disorder (PTSD), suggesting that in some men, psychological aspects are more important than physical aspects while treating ED.

Lead study author Alexander Stridh said, “The placebo response seems largely more important when the cause of [erectile dysfunction] is mainly due to psychogenic factors, as in post-traumatic stress disorder.”

The researchers looked at 63 studies that involved more than 12,500 men, which showed that Viagra and Cialis have a strong efficacy when it comes to treating ED caused by physical conditions, such as diabetes, heart disease, etc.

Stridh said, “The studies included in this meta-analysis mainly were trials on men with [erectile dysfunction] due to cardiovascular disease, diabetes, etc. It is likely that there is a limit to how much the brain can influence erectile function when the problem is mainly dysfunctions in blood vessels or peripheral nerves.”

“This paper highlights the importance of taking into account the underlying cause of [erectile dysfunction] in each individual, which could also help determine what the best treatment option would be,” Stridh continued. “Some men might benefit more from psychotherapy, others with a pharmaceutical approach.”

Stridh explained that it is clear that Viagra and Cialis work well in most cases but it is important to consider the importance of psychological aspects while treating ED, especially in those who have no underlying physiological causes.

Stridh also noted that Viagra and Cialis do not work better than a placebo for men with ED after prostate cancer treatment.

Although the study findings suggest that some men would benefit from psychological counseling, a perceived placebo effect could be natural fluctuations in symptom severity, cautioned Stridh. “Patients have a tendency to seek help when their symptoms are on the worse end and might be improved within a couple of weeks regardless of the treatment given,” he added.