Sniffing human sex-steroid derived compounds modulates mood, memory and autonomic nervous system function in specific behavioral contexts.

We asked whether the effects of exposure to two human sex-steroid derived compounds were context dependent. The effects of sniffing 4,16-androstadien-3-one (AND) and 1,3,5(10),16-estratetraen-3-ol (EST) on mood, memory, and autonomic nervous system responses were explored in 72 participants. Subjects were tested with AND, EST, or a Control compound within four mood contexts: neutral, sexually aroused, sad and happy. These moods were successfully induced using selected film segments (P < 0.0001). During the neutral context, none of the compounds affected mood or autonomic nervous system function. However, compound effects were significantly increased within arousing contexts. During the sexually arousing context, both compounds increased sexual arousal (P < 0.029). During the sad context, AND maintained positive mood in women (P< 0.050) and increased negative mood in men (P < 0.031). Memory for events during the sad context was impaired by AND in women (P < 0.047) but not in men. Finally, effects of AND on physiology were observed during the sexually arousing context whereby AND increased skin temperature in both sexes (P < 0.022) but reduced abdominal respiration rate in men only (P < 0.034). These results suggest that sex-steroidal compounds modulate mood, memory and autonomic nervous system responses and increase their significance within specific behavioral contexts. These findings lend support to a specific role for these compounds in chemical communication between humans.