The article you requested is

How Psychiatrists Can Build New Therapies for Impotence

J Clin Psychiatry 1998;59(2):47-48
Impotence, the inability to maintain an erection sufficient for intercourse, is more properly called erectile dysfunction. Up to 20 million men in the United States have this problem to some degree. The multiple causes of erectile dysfunction include vascular insufficiency, neurologic causes, endocrine pathology (reproductive hormones, thyroid, diabetes), drugs, local pathology in the penis, and psychological/ psychiatric problems.