Men with hypersexual disorder showed higher levels of oxytocin in their blood than did healthy control men without the disorder, in a study with 102 participants.
Hypersexual disorder (HD) is characterized by “excessive and persistent sexual behaviors in relation to various mood states, with an impulsivity component and experienced loss of control,” John Flanagan, MD, of the Karolinska Institutet in Stockholm and colleagues wrote. Although HD is not included as a separate diagnosis in the current DSM, the similar disorder of compulsive sexual behavior is included in the ICD.
Data on the pathophysiology of HD are limited, although a previous study by corresponding author Andreas Chatzittofis, MD, and colleagues showed evidence of neuroendocrine dysregulation in men with HD, and prompted the current study to explore the possible involvement of the oxytocinergic system in HD.
In the current study, published in the Journal of Clinical Endocrinology & Metabolism, the researchers identified 64 men with HD and 38 healthy male controls. The patients were help-seeking men older than 18 years diagnosed with HD who presented to a single center in Sweden during 2013-2014. The men were included in a randomized clinical trial of cognitive-behavioral therapy for HD, and 30 of them participated in a 7-week CBT program.
Oxytocin, secreted by the pituitary gland, is known to play a role in sexual behavior, but has not been examined in HD men, the researchers said. At baseline, the mean plasma oxytocin was 31.0 pM in the HD patients, which was significantly higher than the mean 16.9 pM in healthy controls (P < .001). However, the 30 HD men who underwent CBT showed significant improvement in oxytocin levels, from a mean pretreatment level of 30.5 to a mean posttreatment level of 20.2 pM (P = .0000019).
The study findings were limited by several factors, including the lack of data on oxytocin for a wait list or control group, as well as the inability to control for confounding factors such as diet, physical activity, ethnicity, and stress, and a lack of data on sexual activity prior to oxytocin measurements, the researchers noted.
However, “although there is no clear consensus at this point, previous studies support the use of oxytocin plasma levels as a surrogate variable for [cerebrospinal fluid] oxytocin activity,” the researchers wrote in their discussion. The current study findings support the potential of oxytocin as a biomarker for HD diagnostics and also as a measure of disease severity. Larger studies to confirm the findings, especially those that exclude potential confounders, would be valuable.
Oxytocin may be treatment target
The study is important because of the lack of knowledge regarding the pathophysiology underlying hypersexual disorder, Dr. Chatzittofis of the University of Cyprus, Nicosia, said in an interview. “This is the first study to indicate a role for oxytocin’s involvement” in hypersexual disorder in men. Dr. Chatzittofis led a team in a previous study that showed an association between HD in men and dysregulation of the hypothalamic pituitary adrenal axis.
Dr. Andreas Chatzittofis
In the current study, “we discovered that men with compulsive sexual behavior disorder had higher oxytocin levels, compared with healthy men,” said Dr. Chatzittofis, adding that the take-home message for clinicians is the potential of CBT for treatment. “Cognitive-behavior therapy led to a reduction in both hypersexual behavior and oxytocin levels.” The results suggest that oxytocin plays an important role in sex addiction.
Consequently, oxytocin may be a potential drug target for future pharmacologic treatment of hypersexual disorder, he added.
The study was supported by the Swedish Research Council, the Stockholm County Council, and by a partnership between Umeå University and Västerbotten County Council. The researchers had no financial conflicts to disclose.