Moody Bitches: The Truth about the Drugs You’re Taking, the Sleep You’re Missing, the Sex You’re Not Having and What’s Really Making You Crazy.... Julie Holland

Blood serotonin levels in those newly in love resemble levels in people with OCD. They’re abnormally low for both, about 40 percent of the normal controls.

      Dopamine and serotonin tend to act like they’re on opposite sides of a seesaw. When one is up, the other is often down. Infatuation and initial attraction are characterized by higher dopamine and lower serotonin levels. Higher serotonergic states make it harder to climax, as anyone on sertraline can tell you. So this low serotonergic state helps explain not only why it’s easier for you to climax with your new lover but also your tremendous feelings of angsty need and obsessive ruminations about your newfound love.

      One thing I’d like to stress: women on SSRIs likely won’t experience some of the chemical cocktail of attraction and infatuation. SSRIs create artificially high serotonin levels, decreasing impulsive and compulsive behavior. You have more behavioral control, and you don’t obsess as much about anything, even if you just fell in love, which you may not even do on an SSRI. SSRIs interfere with mating in a few crucial ways. As serotonin and dopamine often balance each other out, if serotonin is too high, dopamine levels will be low. Emotional blunting and apathy result. It’s hard to go out and chase down a guy when your “Go get ’em, tiger!” neurochemical is lacking. Also, there’s less chance of your getting obsessive and fixated on one preferred partner when you are taking a medicine meant to treat OCD. If high dopamine and low serotonin drive the rewarding and obsessive nature of falling in love, being on an SSRI, with its resultant low dopamine and high serotonin levels, won’t drive the behavior. Female rats treated chronically with SSRIs reduce the amount of time they spend near males. Sex researchers are currently conducting studies showing that women on SSRIs rate men as less attractive and spend less time poring over images of their faces than women who aren’t on SSRIs, being “less likely to find those of their chosen sex physically attractive or desirable as a potential romantic or sexual partner.” Just as I recommend my patients get off oral contraceptives when mate shopping, there are reasons to slowly taper off antidepressants as well. If being on SSRIs means you already feel satiated and don’t even look twice at a guy, it’s going to be hard to move forward from attraction and infatuation to attachment.

      Falling in love and choosing a mate rely on sexual attraction and sexual energy. If libido is lowered and sexual response is muted by an SSRI, it seems obvious that this will have a negative impact on the entire process. The neural systems associated with attachment and pair bonding also rely on orgasm and its resulting surge of oxytocin. Because SSRIs make orgasm much more difficult, they jeopardize this major trigger. One way that a woman can judge a potential partner is by how much time and attention he’s putting toward her pleasure. “Scientists think the fickle female orgasm may have evolved to help women distinguish Mr. Right from Mr. Wrong.” A man who can pay extra time and attention to a woman’s needs may also be a better father and more willing to share what he has (a dad and not a cad). Perhaps unconsciously, a woman may use her ability to climax with a certain partner to help her decide whether he is the one for her and her future children, or not so much. If it’s nearly impossible for her to be aroused all the way to orgasm because of her SSRI, then she can’t make use of this measuring device.

      Lust

      From an evolutionary perspective, you could say lust is practice for love. Learning to flirt to attract a mate, and practicing what to do when you find a potential partner, need to be finessed repeatedly over time. The chemistry of lust and attraction are similar, but not the same. Testosterone makes us horny, dopamine keeps us moving forward, and oxytocin frees us up from the fear of strangers so we can shed our clothes and get close. But with lust, a biological drive for sexual gratification, it’s more about testosterone and less about oxytocin.

      Estrogen may make us more receptive to sex, taking the brakes off and helping us to be uninhibited, but testosterone is the gas pedal. Even flirting seems to have some basis in testosterone. While romantic love is reserved for one preferred partner, the target of lust isn’t the perfect man, but rather “almost any semi-appropriate partner”; it’s not Mr. Right so much as Mr. Right Now. Also, the neural mechanism of attraction won’t allow you to fall in love with two different people at once, but you can lust after more than one person at a time. Another key difference is that the fires of lust are quickly doused once the sex is over; with attraction, repeated sex just adds to the buildup of good feelings.

      In women, testosterone is made in the adrenal glands and ovaries, spurring our competitive drive, our assertiveness, and our lust. In adolescence, a girl’s level of testosterone rises five times above normal, but it is in the context of her estrogen increasing ten to twenty times above normal, so it’s balanced out to a large extent. Adolescent boys have a twenty-five-fold increase in their testosterone, unabated by other mitigating hormonal factors, which means they have much higher sex drives than the girls. Also, in boys these levels are static, whereas girls have cyclical variation. Boys’ behavior ends up being much more consistent, basically a constant stream of horny. Boys have more frequent sexual thoughts and more masturbation, which is not to say girls aren’t doing it, too, just not as much. Interestingly, surging testosterone levels in an adolescent girl can signal the time of first intercourse.

      Women have different standards for hookups versus getting hitched. In the past few years, numerous articles have been written about how today’s women, whether in college or out in the world soon after, are so focused on getting their careers off the ground that they prefer more casual sex over complicated long-term relationships. They’d rather get their gratification on their own terms and not muck it up with messy feelings like love. Since “women’s lib” and oral contraceptives have become commonplace, women have had growing freedom in this arena. Having sex has become uncoupled from committed relationships and the responsibilities of motherhood. This is a relatively new phenomenon, and I totally get it. But one warning about one-night stands, just so you aren’t fooling yourself. Lust and sex can trigger feelings of attraction and even love. Rising testosterone levels can enhance dopamine and norepinephrine transmission and lower serotonin, matching the brain chemistry of someone who’s falling in love. And sex can definitely trigger attachment and bonding, due to oxytocin. Testosterone can trigger oxytocin release, and an orgasm will definitely trigger oxytocin release. If you orgasm or cuddle after sex, the bonding hormones may sneak up on you, though you intended your sex to be casual. Thanks to oxytocin, you may find yourself with loving, attached feelings for your Mr. Right Now.

      There is a strong desire in women to be held and cuddled. Many of us will use sex as a means to an end, hoping to have some afterglow and snuggling, willing to trade sex for that experience. Men, too, are eager to be held. A common complaint among men in sex therapy is that they don’t receive enough nonsexual touching. But getting naked and cuddling is going to trigger oxytocin, the bonding hormone. So you may find that it’s hard for you to keep your “friend with benefits” in that same category for long.

      The Chemistry of Sex

      Your brain on sex is like a series of loops. Hormones may trigger behaviors, but just as often, behaviors trigger hormones. Sexual activity stimulates testosterone release, which further revs up desire and triggers dopamine release. This dopamine-laden euphoria and arousal further trigger testosterone release. Sensitivity to touch is enhanced by dopamine and particularly by oxytocin. The more skin-to-skin contact, cuddling, kissing, eye gazing, and nipple stimulation, the more oxytocin gets released, which triggers testosterone, then dopamine.

      Oxytocin and endorphins not only stoke arousal and pleasure but also help produce feelings of closeness and relaxation. As a woman becomes aroused by stimulation