poor body image, history of sexual or emotional abuse), psychiatric comorbidity (e.g., de-
pression, anxiety), or stressors (e.g., job loss, bereavement); 4) cultural/religious factors (e.g.,
inhibitions related to prohibitions against sexual activity; attitudes toward sexuality); and
5) medical factors relevant to prognosis, cour se, or treatment. Each of these factors may con-
tribute differently to the pr esenting symptoms of differe nt men with this disorder. 
Prevalence
The prevalence of lifelong vers us acquired erectile disorder  is unknown. There is a strong
age-related increase in both prevalence and incidence of problems with erection, particu-
larly after age 50 years. Approximately 13%–21%  of men ages 40–80 years complain of oc-
casional problems with erections. Approxim ately 2% of men younger than age 40–50 years
complain of frequent problems with erecti ons, whereas 40%–50% of men older than 60–70
years may have significant problems with erec tions. About 20% of me n fear erectile prob-
lems on their first sexual experience, wherea s approximately 8% experienced erectile prob-
lems that hindered penetration duri ng their first sexual experience.
Development and Course 
Erectile failure on first sexual attempt has been found to be related to having sex with a pre-
viously unknown partner, concomit ant use of drugs or alcohol, not wanting to have sex, and
peer pressure. There is minimal evidence rega rding the persistence of  such problems after
the first attempt. It is assumed that most of these problems spontane ously remit without pro-
fessional intervention, but some men may contin ue to have episodic problems. In contrast,