Such sexual symptoms have long been known side effects of the popular Prozac class of antidepressants, but a growing body of research suggests that they are far more common than previously thought, perhaps affecting half or more of patients.
And a handful of recent medical and psychological journal articles document a small number of cases in which sexual problems remain even after a patient goes off the drugs.
"This is such an upsetting issue," said Aline Zoldbrod, a Lexington psychologist and sex therapist. "There are people for whom SSRIs are really life-saving, I think, but the idea that someone would have to choose between getting out of the darkness of depression and having a good sex life is horrible."
Current warnings on the labels of selective serotonin reuptake inhibitors, or SSRIs, cite early studies in which the prevalence of sexual side effects was lower: 4 percent for Prozac, for example, and ranging from 0 to 28 percent for Paxil.
But more recent studies, in which patients were more likely to be asked about specific sexual side effects and thus more likely to report them, suggest that the ballpark range of those affected by SSRIs is between 30 percent and 50 percent, said researchers including Dr. Richard Balon, a psychiatry professor at Wayne State University who studies the symptoms.
That would translate into millions of affected sex lives among the estimated 1 in 8 American adults who have tried these antidepressants in the past decade or so. Some studies have found the range still higher.
In fact, the dampening sexual effects can be so dramatic that in recent years, the antidepressants have become the leading treatment for premature ejaculation, a study last year found, though they are not approved for that use by the FDA.
"I tell patients there's a good chance they may have sexual problems" while on the antidepressants, "with the most frequent being delayed orgasm," Balon said.
Representatives of some of the companies that make SSRIs pointed out that sexual dysfunction is complex to measure. Patients may be reluctant to discuss it, and it is hard to distinguish issues caused by the drug from problems caused by the underlying mental illness, by diseases such as diabetes, or by other medications, they said. The Prozac label states that "There are no adequate and well-controlled studies examining sexual dysfunction" of patients on Prozac.
In the past two or three years, scattered published case reports from around the country have described patients whose sexual symptoms failed to resolve after going off antidepressants.
Dr. Robert P. Kauffman, chair of obstetrics and gynecology at Texas Tech University, has published accounts of three cases in his practice. "It's probably a small number of men and women," he said, "but I really think it deserves investigation."
Psychologist Audrey Bahrick at the University of Iowa said she became concerned when she observed that several clients whom she followed went off SSRIs and "very, very credibly to me, they did not recover" sexually.
Among their symptoms, she said, were "telltale signs" of SSRI-caused dysfunction, unrelated to the known effects of mental illness. They had "pleasureless orgasms," and "genital anesthesia," in which sex feels no more intense than a handshake. She became particularly concerned about adolescents put on antidepressants, whose sexuality might never have a chance to develop normally.
Bahrick began to explore. She found that post-SSRI sexual effects had never been systematically studied, but she came across a
Among them was Kevin Bennett, a 30-year-old whose sexual function was normal until he was prescribed Prozac at age 18, and who has been impotent ever since, he says; his doctors can find no alternative explanation.
Both Bahrick and Bennett spoke about SSRI effects at a panel of the American Psychological Association last year.
Still, skepticism among psychiatrists remains. Balon said he has seen no such cases in his practice, though he does not rule out the possibility that the syndrome is rare but real.
