The unpalatable truth is that falling in love is, in some ways, indistinguishable from a severe pathology. Behavior changes are reminiscent of psychosis and, biochemically speaking, passionate love closely imitates substance abuse. Appearing in the BBC series Body Hits on December 4, 2002 Dr. John Marsden, the head of the British National Addiction Center, said that love is addictive, akin to cocaine and speed. Sex is a "booby trap", intended to bind the partners long enough to bond.
Using functional Magnetic Resonance Imaging (fMRI), Andreas Bartels and Semir Zeki of University College in London showed that the same areas of the brain are active when abusing drugs and when in love. The prefrontal cortex - hyperactive in depressed patients - is inactive when besotted. How can this be reconciled with the low levels of serotonin that are the telltale sign of both depression and infatuation - is not known.
Other MRI studies, conducted in 2006-7 by Dr. Lucy Brown, a professor in the department of neurology and neuroscience at the Albert Einstein College of Medicine in New York, and her colleagues, revealed that the caudate and the ventral tegmental, brain areas involved in cravings (e.g., for food) and the secretion of dopamine, are lit up in subjects who view photos of their loved ones. Dopamine is a neurotransmitter that affects pleasure and motivation. It causes a sensation akin to a substance-induced high.
On August 14, 2007, the New Scientist News Service gave the details of a study originally published in the Journal of Adolescent Health earlier that year. Serge Brand of the Psychiatric University Clinics in Basel, Switzerland, and his colleagues interviewed 113 teenagers (17-year old), 65 of whom reported having fallen in love recently.
The conclusion? The love-struck adolescents slept less, acted more compulsively more often, had "lots of ideas and creative energy", and were more likely to engage in risky behavior, such as reckless driving.
"'We were able to demonstrate that adolescents in early-stage intense romantic love did not differ from patients during a hypomanic stage,' say the researchers. This leads them to conclude that intense romantic love in teenagers is a 'psychopathologically prominent stage'".
But is it erotic lust or is it love that brings about these cerebral upheavals?
As distinct from love, lust is brought on by surges of sex hormones, such as testosterone and estrogen. These induce an indiscriminate scramble for physical gratification. In the brain, the hypothalamus (controls hunger, thirst, and other primordial drives) and the amygdala (the locus of arousal) become active. Attraction transpires once a more-or-less appropriate object is found (with the right body language and speed and tone of voice) and results in a panoply of sleep and eating disorders.
A recent study in the University of Chicago demonstrated that testosterone levels shoot up by one third even during a casual chat with a female stranger. The stronger the hormonal reaction, the more marked the changes in behavior, concluded the authors. This loop may be part of a larger "mating response". In animals, testosterone provokes aggression and recklessness. The hormone's readings in married men and fathers are markedly lower than in single males still "playing the field".
Still, the long-term outcomes of being in love are lustful. Dopamine, heavily secreted while falling in love, triggers the production of testosterone and sexual attraction then kicks in.
Helen Fisher of Rutger University suggests a three-phased model of falling in love. Each stage involves a distinct set of chemicals. The BBC summed it up succinctly and sensationally: "Events occurring in the brain when we are in love have similarities with mental illness".
Moreover, we are attracted to people with the same genetic makeup and smell (pheromones) of our parents. Dr Martha McClintock of the University of Chicago studied feminine attraction to sweaty T-shirts formerly worn by males. The closer the smell resembled her father's, the more attracted and aroused the woman became. Falling in love is, therefore, an exercise in proxy incest and a vindication of Freud's much-maligned Oedipus and Electra complexes.
Writing in the February 2004 issue of the journal NeuroImage, Andreas Bartels of University College London's Wellcome Department of Imaging Neuroscience described identical reactions in the brains of young mothers looking at their babies and in the brains of people looking at their lovers.
"Both romantic and maternal love are highly rewarding experiences that are linked to the perpetuation of the species, and consequently have a closely linked biological function of crucial evolutionary importance" - he told Reuters.
This incestuous backdrop of love was further demonstrated by psychologist David Perrett of the University of St Andrews in Scotland. The subjects in his experiments preferred their own faces - in other words, the composite of their two parents - when computer-morphed into the opposite sex.
Body secretions play a major role in the onslaught of love. In results published in February 2007 in the Journal of Neuroscience, researchers at the University of California at Berkeley demonstrated convincingly that women who sniffed androstadienone, a signaling chemical found in male sweat, saliva, and semen, experienced higher levels of the hormone cortisol. This results in sexual arousal and improved mood. The effect lasted a whopping one hour.
Still, contrary to prevailing misconceptions, love is mostly about negative emotions. As Professor Arthur Aron from State University of New York at Stonybrook has shown, in the first few meetings, people misinterpret certain physical cues and feelings - notably fear and thrill - as (falling in) love. Thus, counterintuitively, anxious people - especially those with the "serotonin transporter" gene - are more sexually active (i.e., fall in love more often).
Obsessive thoughts regarding the Loved One and compulsive acts are also common. Perception is distorted as is cognition. "Love is blind" and the lover easily fails the reality test. Falling in love involves the enhanced secretion of b-Phenylethylamine (PEA, or the "love chemical") in the first 2 to 4 years of the relationship.
This natural drug creates an euphoric high and helps obscure the failings and shortcomings of the potential mate. Such oblivion - perceiving only the spouse's good sides while discarding her bad ones - is a pathology akin to the primitive psychological defense mechanism known as "splitting". Narcissists - patients suffering from the Narcissistic Personality Disorder - also Idealize romantic or intimate partners. A similar cognitive-emotional impairment is common in many mental health conditions.
The activity of a host of neurotransmitters - such as Dopamine, Adrenaline (Norepinephrine), and Serotonin - is heightened (or in the case of Serotonin, lowered) in both paramours. Yet, such irregularities are also associated with Obsessive-Compulsive Disorder (OCD) and depression.
It is telling that once attachment is formed and infatuation gives way to a more stable and less exuberant relationship, the levels of these substances return to normal. They are replaced by two hormones (endorphins) which usually play a part in social interactions (including bonding and sex): Oxytocin (the "cuddling chemical") and Vasopressin. Oxytocin facilitates bonding. It is released in the mother during breastfeeding, in the members of the couple when they spend time together - and when they sexually climax. Viagra (sildenafil) seems to facilitate its release, at least in rats.
It seems, therefore, that the distinctions we often make between types of love - motherly love vs. romantic love, for instance - are artificial, as far as human biochemistry goes. As neuroscientist Larry Young’s research with prairie voles at the Yerkes National Primate Research Center at Emory University demonstrates:
"(H)uman love is set off by a “biochemical chain of events” that originally evolved in ancient brain circuits involving mother-child bonding, which is stimulated in mammals by the release of oxytocin during labor, delivery and nursing."
He told the New-York Times ("Anti-Love Drug May Be Ticket to Bliss", January 12, 2009):
“Some of our sexuality has evolved to stimulate that same oxytocin system to create female-male bonds,” Dr. Young said, noting that sexual foreplay and intercourse stimulate the same parts of a woman’s body that are involved in giving birth and nursing. This hormonal hypothesis, which is by no means proven fact, would help explain a couple of differences between humans and less monogamous mammals: females’ desire to have sex even when they are not fertile, and males’ erotic fascination with breasts. More frequent sex and more attention to breasts, Dr. Young said, could help build long-term bonds through a “ cocktail of ancient neuropeptides,” like the oxytocin released during foreplay or orgasm. Researchers have achieved similar results by squirting oxytocin into people’s nostrils..."
"A related hormone, vasopressin, creates urges for bonding and nesting when it is injected in male voles (or naturally activated by sex). After Dr. Young found that male voles with a genetically limited vasopressin response were less likely to find mates, Swedish researchers reported that men with a similar genetic tendency were less likely to get married ... 'If we give an oxytocin blocker to female voles, they become like 95 percent of other mammal species,' Dr. Young said. 'They will not bond no matter how many times they mate with a male or hard how he tries to bond. They mate, it feels really good and they move on if another male comes along. If love is similarly biochemically based, you should in theory be able to suppress it in a similar way.'"
Love, in all its phases and manifestations, is an addiction, probably to the various forms of internally secreted norepinephrine, such as the aforementioned amphetamine-like PEA. Love, in other words, is a form of substance abuse. The withdrawal of romantic love has serious mental health repercussions.
A study conducted by Dr. Kenneth Kendler, professor of psychiatry and director of the Virginia Institute for Psychiatric and Behavioral Genetics, and others, and published in the September 2002 issue of Archives of General Psychiatry, revealed that breakups often lead to depression and anxiety. Other, fMRI-based studies, demonstrated how the insular cortex, in charge of experiencing pain, became active when subjects viewed photos of former loved ones.
Still, love cannot be reduced to its biochemical and electrical components. Love is not tantamount to our bodily processes - rather, it is the way we experience them. Love is how we interpret these flows and ebbs of compounds using a higher-level language. In other words, love is pure poetry.