Verified by 
This article was originally published on Medium (P.S. I Love You).
Picture this: you meet a handsome man at a party. You hear things about him that are unsettling, but you are very attracted to him. He is cute. Really cute. You go home and the sex is great… you want to drink him in.
When he fails to call the next day, at first you ignore it. He is probably busy, right? Then you see him another time. Again, the sex is great. You cook him dinner and he likes that. He starts to come over more often. You have more sex, but you never go out. Why doesn’t he take you out? But, the sex is good… really good. Then one day, he stops calling. Ouch! It hurts your feelings really bad. You start to miss him. Why is that? You know he is not good for you. It’s frustrating to feel this way when your mind is saying “let it go…”
When you have sex with the same person repeatedly, you develop a neurochemical bond to them. Birth control was not a thing in evolution. In evolutionary terms, sex produced babies which led to vulnerability. Sex created a bonding process important to humans as a species because it made reproduction more successful. There are entire research studies dedicated to this very topic, including “Neurobiology of Sexual Desire" by Suck Won Kim and a group of other researchers.
Parents who are bonded together are more likely to help each other raise their offspring during the most vulnerable phase of development. Whether that is just for one breeding season, as is the case with king penguins, or for several years in the case of humans.
Oxytocin, a neurotransmitter in the brain that promotes bonding, is joined by vasopressin, a hormone that influences feelings of possessiveness and jealousy, and serotonin, a neurotransmitter that can fuel the more obsessive aspects of romantic love. You can read more about this in C. Sue Carter, Ph.D.’s extensive research, “The Role of Oxytocin and Vasopressin in Attachment.”
Sex also stimulates the dopamine or “reward” system in our brain, which motivates us to pursue sex as a species and rewards us for doing so with pleasurable feelings.
Even “casual” sex serves up a potent chemical cocktail, with natural but potentially unsettling effects. The downside to the intense bonding that can accompany sexual activity is that it is all too easy to become bonded to a partner who is not suited to be part of our life long-term.
We can become emotionally overwhelmed by intense feelings of desire that create a roller-coaster experience ranging from the ecstasy of being in love to crushing heartbreak when the relationship ends. I have seen patients who were unprepared for such intensity and who developed obsessional thinking and serious depression that manifested in self-esteem crises, self-injury, and even suicide attempts. Others may continually seek new relationships, avoiding the strong feelings of attachment and instead chasing the more immediate “high” of sexual activity.
Understanding the underlying biological processes that occur when we become intimate with someone allows us to make more knowledgeable decisions. We can all get swept up in the elation accompanying a new intimate relationship. Know that our emotional mind is influenced by hormones, evolution, biology, and cultural influences that might be telling us to do things that jeopardize our ultimate well-being. However, our wise mind can use information from our emotions and our reason to create a balance.
The message here is that even with the hormone highs of a new romance, it’s important to remind yourself that this might not be the be-all and end-all. Keep a level head and remember that life is long!
After a breakup and when all that dopamine from the sex wears off, things will get easier. Frame a failed relationship as a lesson learned in preparation for the next relationship. Our biology wants us to fall in love when we have sex. Remember it is hard to fight your biology. Do not take it too hard if you fall for the wrong person. Learn from your mistakes and move on.
Follow me on Instagram @shamelesspsychiatrist and sign up for my newsletter.
