Male Sexual Dysfunction Epidemiology

In the Massachusetts Male Aging Study, a community-based survey of men between 40 and 70 years of age, 52% of respondents reported some degree of ED: 17% mild, 25% moderate, and 10% complete. Although the prevalence of mild ED remained constant (17%) between the ages of 40 and 70, there was a doubling in the number of men reporting moderate ED (from 17% to 34%) and a tripling in the number of men reporting complete ED (from 5% to 15%). Among the major predictors of ED are diabetes mellitus, heart disease, hypertension, and decreased high-density lipoprotein level. There is a higher prevalence of ED in men who have undergone radiation or surgery for prostate cancer. The psychological correlates of ED include depression and anger (Feldman et al, 1994). In the National Health and Social Life Survey in men aged 18-59, other male sexual dysfunctions were also found to be highly prevalent: premature ejaculation (28.5%), lack of sexual interest (15.8%), anxiety about sexual performance (17%), and lack of pleasure in sex (8.1%) (_{Laumann et al, 1994}).

Classification & Pathogenesis

A new classification of ED has been recommended by the International Society of Impotence Research (Lizza and Rosen, 1999, Table 37-3). In the 1950s, 90% of cases of ED were believed to be psychogenic. Most authors now believe that mixed organic and psychogenic ED is the most common.

Psychological Disorders

Many psychologic conditions (performance anxiety, strained relationship, lack of sexual arousal, depression, and schizophrenia) can either cause or aggravate ED. The pathogenesis of psychogenic ED is still speculative. The most cited include imbalance of central neurotransmitters, over-inhibition of spinal erection center by the brain, inadequate NO release, and sympathetic overactivity.