Loss of libido in Parkinson's disease

Introduction. Sexual dysfunction is a frequent but neglected problem in Parkinson's disease (PD). Decreased sexual desire in PD correlates with reduced general satisfaction from life. Many variables might be related to the loss of libido in PD and they have not been carefully investigated yet. Aim. To assess the frequency of loss of libido in PD and its relation to neurological symptoms, depression, anxiety, fatigue, and cognitive performance. Methods. The response of 90 PD patients of both genders toitem "loss of libido" from the Beck Depression Inventory (BDI) was analyzed. A structured psychiatric interview (MINI-Plus) evaluated the presence of major depression and generalized anxiety disorder. Clinical assessment also comprised neurological examination, which included all sections of the Unified Parkinson's Disease Rating Scale (UPDRS), Hoehn-Yahr and Schwab-England Scale (SES). The Frontal Assessment Battery (FAB), the Mini Mental State Examination (MMSE), and the PD Fatigue Scale (PDFS) were also performed. Main Outcome Measures. Frequency of loss of libido and its main predictors. Results. The frequency of loss of libido was 65.6%, and 42.6% of men also complained of erectile dysfunction. Ageing (P = 0.012), female gender (P < 0.001), lower education (P < 0.001), and depression (P = 0.006) associated with decreased sexual desire. Higher BDI scores (P < 0.001) correlated with a greater loss of libido. Decreased interest in sex was not associated with antidepressants. Neurological features associated with higher loss of libido were predominance of motor symptoms on the left side of the body (P = 0.026), autonomic dysfunction (P = 0.012), higher UPDRS scores (P = 0.006), and lower scores on SES (P = 0.003). In men, erectile dysfunction associated with decreased interest in sex (P < 0.001). Patients with lower performance on FAB (P < 0.001) and MMSE (P = 0.002), and with higher scores on PDFS (P < 0.001) also had less interest in sex. A multiple regression analysis indicated age, gender and BDI score as the main predictors of loss of libido. Conclusions. Loss of libido is frequent in PD and depression may be its main predictor. However, decreased interest in sex was not associated with antidepressant therapy. Thus, loss of libido resulting from depression may be effectively treated, and physicians should be encouraged to assess these symptoms in their patients.