The neurohormone oxytocin has been found to influence a range of social and affiliative behaviors (MacDonald and MacDonald, 2010). Administration of oxytocin (OT) can enhance trust, empathy and a host of other pro-social feelings (MacDonald and MacDonald, 2010). We know that dreams, particularly dreams associated with the REM state, are primarily about social emotions and social interactions with people close to us and with perfect strangers. Could it be then that OT influences dream content when dreams depict social interactions?
There is evidence that oxytocin influences sleep processes: Levels of oxytocin peak at around 5 hours after sleep onset when REM sleep predominates. Blagrove and his colleagues in Britain have been doing some exciting work on this issue. They (Blagrove et al, 2011) recently reported that OT levels are also correlated with stages of light sleep (Stage 2 in the old nomenclature). Dreams from Stage II are just as filled with social interactions as dreams from REM sleep.
Oxytocinergic activity, furthermore, is regulated by nuclei within the paraventricular nucleus of the hypothalamus close to centers that regulate arousal and sleep-wake states. In addition, oxytocin is known to modulate reactivity of the amygdala to social emotions and the amygdala, in turn, is modulated by REM sleep. Despite the multiple ways in which oxytocin may influence sleep and dreams, no study, as far as I know, has directly examined effects of oxytocin administration on sleep and dreams.
I suspect OT dramatically influences the social emotions we find in dreams. If OT influences social emotions in waking life there is no reason to believe it doesn't do so in dreams.
Take the fascinating case of sex in dreams. Everyone has experienced dreams of sexual contact and even orgasm due to a dream of sexual contact with someone we love or desire. Now in normal waking life oxytocin is the hormone that mediates orgasm. It is very likely it does so in dreams as well. Then there is the fact that REM sleep is consistently associated with erections in males and clitoral engorgement in females. In waking life oxytocin is crucial for these physiologic responses. It seems likely that OT would mediate such responses in dreams as well.
Previous research has demonstrated that sleep and dream recall varies significantly by social/relationship attachment orientation and status. Persons classified with ‘anxious' attachment styles enter sleep faster, sleep longer, and recall more negative dreams and nightmares than persons classified with ‘avoidant' orientations. Oxytocin levels and activity may be the factor that connects social relationships in waking life and depictions of social relationships in dreams.If so, so what?
Well, for starters, a demonstration that OT modulates social emotions in dreams will give us a clue as to how the brain generates dreams and dream content. Interpretation of dreams would receive a boost as well. Whatever else they are dreams would be seen as another form of social cognition. But even more importantly if OT were found to significantly modulate sleep and dreams it may be that OT levels could be manipulated to improve sleep and dreams in people who suffer from sleep disorders.
Intranasal OT therapy has been shown to be a safe and effective treatment for some psychiatric disorders such as social anxiety and autism (see review in MacDonald et al 2011). It may also be a safe and effective treatment for selected sleep and dream disorders like depression and recurrent nightmare syndromes. Depression is a disorder both of sleep and social withdrawal. Oxytocin could influence both of those symptoms of depression. Current evidence suggests that OT attenuates amygdalar hyper-responsivity to negatively valenced emotional stimuli (e.g., Kirsch et al., 2005). Given that nightmares are associated with abnormal amygdalar activity administration of OT may help to ameliorate severity of nightmares.