Oxytocin has established a reputation as the “love hormone,” playing a significant role in sexual arousal and maternal bonding. But a new study claims there may be a darker side to oxytocin; the way it influences our actions is comparable to the effects of alcohol.
Dr. Ian Mitchell, of the School of Psychology at the University of Birmingham in the UK, and colleagues publish their findings in Neuroscience and Biobehavioral Reviews.
Produced by the hypothalamus in the brain and secreted into the bloodstream by the posterior pituitary gland, oxytocin is a hormone and a brain neurotransmitter that controls lactation and contraction of the womb during childbirth.
Oxytocin is also known to influence emotional, cognitive and social behaviors, including maternal bonding, sexual arousal, anxiety, fear and trust.
According to Dr. Mitchell and colleagues, oxytocin increases behaviors such as altruism, empathy and generosity, making us more willing to trust others, while suppressing prefrontal and limbic cortical circuit activity in the brain to reduce anxiety, fear and stress.
Since alcohol can also trigger such behaviors, the team set out to determine whether alcohol and oxytocin have similar effects on the brain.
To reach their findings, the researchers analyzed a number of studies assessing the effects of both oxytocin – administered nasally – and alcohol on the brain.
The team found the two compounds worked in similar ways. Though oxytocin and alcohol target different brain receptors, they both have similar effects on Gamma-Amino Butyric acid (GABA) signaling in the prefrontal cortex and limbic areas of the brain.
“These neural circuits control how we perceive stress or anxiety, especially in social situations such as interviews, or perhaps even plucking up the courage to ask somebody on a date,” says Dr. Mitchell. “Taking compounds such as oxytocin and alcohol can make these situations seem less daunting.”
The team says their findings may explain why many people are tempted by alcohol to ease nervousness. “The idea of ‘Dutch courage’ – having a drink to overcome nerves – is used to battle those immediate obstacles of fear and anxiety. Oxytocin appears to mirror these effects in the lab,” explains study author Dr. Steven Gillespie, also of the School of Psychology.
However, the researchers recommend against the use of both oxytocin and alcohol for boosting confidence, pointing to the negative effects of each compound.
They note that both alcohol and oxytocin can cause people to become more aggressive, boastful, envious of others, and encourage favoritism toward an individual’s “in-crowd.” What is more, by influencing our sense of fear and perceptions of trust, both compounds may encourage unnecessary risk-taking.
However, while there is clearly a dark side to oxytocin, Dr. Gillespie notes that the compound could have clinical uses:
“I don’t think we’ll see a time when oxytocin is used socially as an alternative to alcohol. But it is a fascinating neurochemical and, away from matters of the heart, has a possible use in treatment of psychological and psychiatric conditions.
“Understanding exactly how it suppresses certain modes of action and alters our behavior could provide real benefits for a lot of people. Hopefully this research might shed some new light on it and open up avenues we hadn’t yet considered.”
In March, a study led by researchers from Harvard Medical School in Boston, MA, found oxytocin may also have an impact on weight – in men, at least. The team found a single dose of oxytocin administered nasally reduced calorie intake and consumption of fatty foods in healthy men.