Drug of Choice: Amour

   Chemical Formula for  Oxytocin

   Chemical Formula for Oxytocin

First hit. Body tingles, soul shivers. Colors bleed vibrant. Time stands still. Everything suggests divine presence. Second hit. Worries fade away, replaced by euphoria. Obsession begins, craving more. Third hit. Calm, happiness, contentment. Need a bigger dose to feel. Need a bigger dose to think. Need a bigger dose to function. Fourth hit. Can’t live without it. Too much time between hits. Getting fidgety. Moral compass points only to the next hit. Insanity lingers. Fifth hit. Fatal.

Is this the cycle of a drug addict? Or a human falling in love?  Turns out, it doesn’t matter. The brain can’t distinguish the difference

“This is the chemical formula for love: C8H11NO2+C10H12N2O+C43H66N12O12S2
dopamine, serotonin, oxytocin. It can be easily manufactured in a lab, but overdosing on any of them can cause schizophrenia, extreme paranoia, and insanity.

Let that sink in."


“Spontaneous romantic love makes a man free and in the moment dependent… spontaneous love can become unhappy, can reach the point of despair.” Søren Kierkegaard

It was electric. Time stood still when they spoke. After only their first encounter, he was betwitched.  Unconsciously, he became addicted to her details. Her swim-in-me eyes, her intoxicating perfume, the way she tamed her wild hair around her index finger, twirling while listening. In his brain, dopamine was released in huge quantities in the nucleus accumbens (NAC) shell which acts to increase the salience of incentive cues that predict the reward. 

Basically, his brain is saying: “good feelings. See what happens next.”

“Addiction has been conceptualized as a process that highjacks the brain’s learning and reward circuity through hyper physiologic activation of dopamine and opioid receptors.”  In other words, love literally makes you blind. 

The illusion that time is static can be explained by an evolutionary theory which states that changes in time perception are mediated by changes in arousal – thus facilitating a role in survival. 

Simply paying close attention to the object of desire could benefit our species.

Dr. Arantes at University of Cantebury has recently received a grant to delve deeper and explore “what happens automatically and instinctively in the cognitive system during interpersonal attraction.”  Preliminary results could reveal how rules of relativity are bent when we are deeply attracted to someone.

The drug addict’s brain, after just one hit of their favorite substance, behaves in a similar way.  The appropriate sensory modalities for the drug - a slight burning sensation down the throat, overall body warmth and sustained sociability – are coded as reality-altering and rewarding and dopamine is released in the NAC. 

“I, who usually long without longing, as though I am unconscious and absorbed in neutrality and apathy, really, utterly long for every bit of you.” Franz Kafka, Letters To Milena 

Suddenly he disappears. For years he would be readily available for any planned activity, often in the know about the latest trends, quoting last night’s Game of Thrones monologue from memory. No longer.  The only stark he can imagine is her naked.  He craves her more. He is falling in love, his brain falling in attachment. 

Love is a broad, often elusive term. Attachment is defined as an evolved, biologically rooted motivation system that dictates the organization of behaviors in children to promote proximity to one or more attachment figures.

Hence, it is hypothesized that humans neurobiologically regulate attachment the same way we regulate thirst, feeding, temperature and sleep-wake cycles – unconsciously. With each titillating text, each anticipated activity and colorful reunion endorphins are released, activating opioid receptors and feeding back to inhibit both the stress response and hypothalamic oxytocin release. We seek out comfort and safety in another precisely because we are programmed to maintain homeostasis.  

The drug addict begins taking larger and larger amounts over a longer period to sustain the high.  Important social, occupational or recreational activities are given up or reduced. As addiction is rewiring the brain and teaching reliance on drugs to fulfill attachment needs, the opioid system is becoming taxed and the euphoric effect draws further and further away. It should be noted that “insecure attachment styles, such as avoidant attachment (described as avoidance of social intimacy and overvalued independence), are associated with a higher risk for addictive behaviors.” Additionally, traits defining an addictive personality (sensation-seeking, impulsivity and compulsivity) raise the risk significantly. 

“I liked it. I craved it. I wanted more and I took it. I took it like I needed it, like my life had a limit and if I didn’t get as much of it as I could, I’d quit breathing the next instant.” Kristen Ashley Until the sun falls from the sky

After several dates, the bond becomes stronger as oxytocin and vasopressin are released, converging in the mesolimbic dopamine pathway to increase the salience of social cues and information.  The oxytocin system helps code the beloved as “an object of care.”  The couple becomes inappropriately cute in public and all surrounding parties twinge. If anybody so much as glances at the mate, the vasopressin system is engaged, constricting blood vessels – “an evolutionary elaboration of circuitry for aggression and territoriality, which identifies the partner as an extension of territory.” 


Assuming all the wooing was effective, he does to her what spring does with cherry trees. It is during mating that the strongest bond is developed.  Dopamine, oxytocin, serotonin and vasopressin simultaneously engulf the brain and body in maddening waves. For some, this neurobiological climax is the point of no return – an unparalleled high.

Similarly, in the addicted brain, the sights, sounds and unique behaviors of the drug are being coded as euphoric. The individual will do anything to acquire the drug. The drug is all they think about, and with every hit they fall in love more. In contrast to social interactions, oxytocin and vasopressin have no known role in the drug-addict brain.  At this stage, over-dosing becomes a real threat. 

Romantic love is mental illness. But it’s a pleasurable one. It’s a drug. It distorts reality, and that’s the point of it. It would be impossible to fall in love with someone you really saw.”  Fran Lebowitz
Image Credit:  Here

Image Credit: Here

Even though most mammals rarely form monogamous relationships (only 3%-5% in the entire species), humans belong to a class of mammals that form “pair bonds” for life.  Prairie voles fall into this category, and have been studied extensively to unearth reasons why humans choose to stay together. For example, when a male vole mates with a female, vasopressin is released which encourages him to keep mating with the same female. And then cuddle her. Voles are big cuddlers.  This behavior can also be explained physiologically: Prairie voles, unlike most other branches of their species, have a high number of vasopressin receptors in their brain, making this feedback loop powerful. Incredibly, females can sense which males have an increased number of these pro-cuddle receptors and tend to pick them as mates.

It’s thought human pairing works in a similar way. While the euphoric excitement that comes with a new relationship subsides, a subdued sense of contentment replaces it.  Movie watching and cuddling ensues. Even though encounters with new potential mates cause novelty-induced dopamine release, a separate dopamine signal promotes rejection and aggressive responses to defend the territory while also promoting lovemaking.

Due to dependence-induced escalation of the object of addiction, the relationship may turn sour at this point, but could continue. A sensation of not being able to stay away from the partner results in several failed break-up attempts.  

Addiction “rewires” the attachment system, leading to neglect of social motivation and reward, and instead, relations on drugs to fulfill attachment needs. 

Image credit here:  Here

Image credit here: Here

Similarly in the drug-addicted brain, there is a transition to contentment from the initial euphoric high. The addict increases the dose and begins to act morally irresponsible to obtain the drug. Analogous responses lead to drug tolerance, diminished reward, compulsive and escalating abuse and transition from euphoria to negative affect. There are several unsuccessful efforts to cut down or control the use of the drug, as CRF “increases drug-craving, generating a powerful motivation to continue to use or relapse from abstinence.” 

“Addiction isn’t about substance – you aren’t addicted to the substance, you are addicted to the alteration of mood that the substance brings.” Susan Cheever

At the relationship’s dénouement, a withdrawal-induced anxiety with symptoms such as compulsive phone checking, sweaty palms and increased heart rate occurs due to a release of corticotropin-releasing factor (CRF) into the NAC shell. There is depression, anhedonia and lots of junk food.  Memory bombs explode from every corner, as everything reminds one of the other. CRF release might increase the incentive value, creative a positive incentive to return to the partner. Even though their behavior was unforgivable, the brain protests and remembers them positively. 

Similarly, the CRF circuitry is activated when the drug of choice is no longer available. An acute physical reaction including sweating and shaking, and even death can occur. Recent pilot treatments with oxytocin have shown promise to “reset” the adaptive fear association with the drug during the withdrawal period.  In the case of a break-up, it may act to mitigate the crushing symptoms and decrease probability of a relapse. 

“There ain’t no cure for love.”  Leonard Cohen

If the CRF circuitry is very strong, a positive motivational state will drive the subject back towards the subject of addiction. In other words – the couple reunites.  When relapse is impossible, due to either loss of a partner or continued abstinence, a persistent anxiety and depression state can result. Some might swear never to “become addicted again.”

Yet, love is a powerful drug. Given the irrefutable evidence that “every neurochemical system implicated in addiction also participates in social attachment,” it’s worth becoming addicted. If only for the cuddling. 

Happy Valentine's Day to all the brains addicted to love! 
ResearchBlogging.org Burkett, J., & Young, L. (2012). The behavioral, anatomical and pharmacological parallels between social attachment, love and addiction Psychopharmacology, 224 (1), 1-26 DOI: 10.1007/s00213-012-2794-x
ResearchBlogging.org Stauffer, C., & Woolley, J. (2014). Can We Bottle Psychosocial Treatments for Addiction? The Role of Oxytocin The Journal of Clinical Psychiatry, 75 (09), 1028-1029 DOI: 10.4088/JCP.14ac09437