One of my more interesting recent cases was that of a young gay man who came to us in despair because he was in love with his heterosexual roommate.

 The two of them were extremely close: eating dinner together, going to movies, and generally engaging in very couple-like domestic activities. They also had an unusually open relationship. The gay man had confessed his ardor to the roommate, and the roommate, while he did not return the sexual feelings, was mind-bogglingly relaxed about the whole issue and the two of them remained as close as before.

Matters took a turn for the worse when the roommate acquired a girlfriend. Naturally the gay man could not stand the girlfriend and resorted to drinking alone in his room or going for long drives whenever she was around. Ultimately he became so depressed and consumed by the situation that he was unable to work, could not sleep, lost interest in his hobbies, and finally sought psychiatric help.

At first the treatment team was perplexed by the behavior of the roommate. We speculated that perhaps he was a closeted homosexual who unconsciously returned the feelings, or else that he simply couldn't bring himself to give up the incredibly cheap rent offered by his lovesick roommate (who owned the apartment).

The answer turned out to be rather different. I sat down with both men for a frank discussion.  At least to casual observation, their relationship appeared as close and honest as had been described to me by the gay patient. Together we dissected the timeline of their relationship. It seemed they had been ordinary good friends until they began to use the drug Ecstasy (MDMA). Over the course of a summer they had used the drug weekly together - rarely with anyone else.  In the process they cemented a bond that ultimately resembled, more than anything, a love relationship.

Ecstasy is a drug of great emotional power. Roughly, it works by reversing the direction of the reuptake transporter that vacuums leftover serotonin out of the synaptic cleft (see Rudnick and Wall). This dumps enormous amounts of serotonin into the synaptic cleft - far more than would ever normally be present there at one time. Just as chocolate cake overstimulates the taste receptors that evolved to detect the more mild and nuanced sweetness of fruit, Ecstasy overstimulates circuits designed to underlie the natural pleasures of romantic attachment and sensory experience. 

In a stark demonstration that love really is just chemistry, Ecstasy can make you feel a gush of deep affection for just about anyone sharing the experience with you. It's Cupid's Arrow in a little round pill.

In this particular case, these two men overstimulated their 'love circuits' together over and over again for an entire summer.  Little wonder that the gay one fell in love with his friend. As for the straight roommate, evidently Ecstasy can't alter sexuality (unsuprising, as Ecstasy has little to do with sexual feelings, and in fact often inhibits them). But it did seem to have triggered many of the other hallmarks of romantic love. The straight man gazed affectionately at his roommate, expressed all manner of deep and abiding emotion for him, was wracked with guilt for the suffering he'd caused. Everything was there but the sexual attraction.

That emotion has a chemical basis is nothing new, and at this point carries little shock value. Yet it is still occasionally difficult to believe how easily we can manipulate our deepest emotions with a little diddle to the neuropharmacological machinery.

What was the cure for this young man? Fighting fire with fire, I prescribed him Prozac. Prozac works by paralyzing the same reuptake transporter that is reversed by Ecstasy. Instead of being vacuumed back out of the synaptic cleft when their job is done, the serotonin molecules loiter around in the cleft. The simple way to think about this is that more serotonin in the cleft equals more happiness, duh - though in fact the biological effects of SSRIs such as Prozac are somewhat more complicated than that (see Nutt et al for a useful summary).

As one might expect, then, Prozac blocks the effects of Ecstasy (see Tancer and Johanson). With Prozac in your system paralyzing your reuptake transporters, a nice fat pill of E has no more effect than a sugar tab. I thought this little-known side effect might prove useful in this particular patient's case.

A more well-documented side effect of SSRIs is inhibition of sexual function, including the ability to orgasm (see Rosen et al. for review). In addition to this, there are some anecdotal reports that SSRIs such as Prozac have adverse effects on romantic love. This is a much mushier and less well-documented realm. I found nothing about it on PubMed, though I did find a bit of schlock in Psychology Today that discusses the phenomenon. If this latter bit did turn out to be true, I would wonder whether the effect were secondary to inhibition of sexual desire or whether it involved a distinct group of neural circuits.

Some anecdotal reports suggest SSRIs may in fact dull the capacity for deep emotion. You don't feel sad anymore, you even feel kind of happy, but the happiness is a sort of pleasant zoning out rather than a meaningful joy. Indeed, by some accounts the entire spectrum of emotion is flattened out (see, for example, comments posted by readers on this WebMD blog).

Much has been made of the possibility that we are depriving ourselves of essential human experiences by medicating away our emotions (see, for example, this review of Eric Wilson's book Against Happiness). Of course, many others more articulate than I have also argued the opposite side of the story (see this other review of Peter Kramer's Against Depression).  It's kind of interesting to think that we could also medicate ourselves into supranormal states of emotion with MDMA and other 'anti-Prozacs'.

As is often true, I find myself taking a position somewhere in the middle. I don't want my patient to be zoned out forever, but I can't help but think that he's already had more than enough character-building for a while. A little Prozac in this case is probably a good thing.