Neurodegenerative diseases affect multiple domains of functioning, including cognition, emotion, and motor behavior. Sexual functioning is a domain that may also be affected but has received less attention within the field of research. Extant literature on sexual functioning among patients with neurodegenerative diseases tends to focus on clinical and caregiver reports of patient sexual behavior. To understand the response to sexual stimuli in patients with neurodegenerative diseases using non-invasive laboratory-based measures, two studies were conducted.
The first study examined reactivity of three diagnostic groups (18 behavioral variant frontotemporal dementia, 9 Alzheimer’s disease, and 23 healthy controls). Participants were shown an erotic film clip and their responses: physiological, facial behavior, and self-reported affective response were recorded. A group difference emerged in physiological reactivity to the erotic film. More specifically, patients with behavioral variant frontotemporal dementia showed diminished physiological arousal in comparison with healthy controls. I found no statistically significant group differences in facial behavior and self-reported affective responses. With respect to facial behavior, nearly 90% of participants did not show the target facial behavior of happiness while watching the erotic film. With respect to self-reported affective response, all groups reported feeling sexually aroused to a small extent. Results suggest that the physiological measure, which captured more automatic responses to sexual stimuli, was better able to detect diagnostic group differences than facial behavior or self-reported affective response.
The second study examined whether the responses (physiological, facial behavior, and self-reported affective response) of patients with neurodegenerative diseases to sexual stimuli were associated with spousal caregiver depression and marital satisfaction. In addition, I assessed whether these associations were mediated by caregiver reports of patient sexual behavior using a multiple mediation model. Sixty-two patients with neurodegenerative diseases were shown the same erotic film clip as in study 1, and their respective spousal caregivers completed measures of depression, marital satisfaction, and patient sexual behavior. I found an association between patient facial behavior and caregiver marital satisfaction, in which higher displays of happiness on patients’ faces while watching the erotic film was associated with lower caregiver marital satisfaction. A marginal association was found between patient self-reported affective response and caregiver marital satisfaction, in which greater endorsement of feelings of sexual arousal while watching the erotic film was associated with lower caregiver marital satisfaction. No associations were found between patient physiological response and caregiver marital satisfaction or between any of the laboratory-based measures and caregiver depression. Although mediation did not occur in any of the analyses, one of the two mediators revealed that the less sexually responsive the patients were toward their spousal caregivers, the higher the caregiver depression and the lower the caregiver marital satisfaction.
The studies show that laboratory-based measures of response to sexual stimuli and caregiver reports of patient sexual behavior can reveal important information about the influence of neurodegenerative diseases on marital relationships.