The Drug of Love

Much to the dismay of people who believe that defining love should be left in the hands of poets and songwriters, or, better yet, on the lips of lovers who experience it, scientists are exploring whether love—from infatuation to the consummate style—can be explained by a person’s biology. Neuroscientist Niels Birbaumer and his colleagues were the first current-day scientists to examine this possibility. The researchers placed electrodes on the scalps of men and women and measured their brains’ electrical activity using an electroencephalograph, or EEG, machine as the participants envisioned a joyful scene with a loved one, a jealous scene, and a control scene—an empty living room. Half of the men and women were passionately in love at the time; the other half were not emotionally involved with anyone. When the researchers compared the brain waves of the people who were and were not passionately in love, they found huge differences in brain activity during imagery of a scene with a loved one. Those who were passionately in love showed much more complex brain-wave patterns and much more widespread activity throughout the brain. As noted by the authors, “Subjects in love carry their emotional ‘burden’ like a snail’s house into the laboratory of a physiologist.” And on the basis of their findings, the research team concluded that passionate love is like “mental chaos.”

In 2003, a decade after Niels Birbaumer’s discovery, Andreas Bartels and Semir Zeki, two neuroscientists in London, began scanning the brains of young lovers to see what it means to “fall in love.” They selected seventeen men and women who met the criteria for being “truly, deeply, and madly in love” and observed their brains using a functional magnetic resonance imagery, or fMRI, scanner, which is able to record changes in blood flow to various parts of the brain. When nerve cells in the brain are active, they consume oxygen. Oxygen is carried to the brain are active, they consume oxygen. Oxygen is carried to the brain by hemoglobin in red blood cells from nearby capillaries. Hence, blood flow to the brain and amount of brain activity are closely related.

As the participants’ brains were being scanned, the researchers showed them pictures of either their beloved or nonromantic friends. Only when they were gazing at the photographs of their loved ones did the participants’ brains show intense activity in areas associated with euphoria and reward—and diminished activity in brain regions associated with sadness, fear, and anxiety. In fact, the pattern of brain activity that occurred when the participants viewed their lovers was not unlike the pattern of brain activity seen when a person is under the influence of euphoria-inducing drugs such as cocaine. The brains excited with love also showed decreased activity in regions associated with critical thought, which might explain why people who are acutely in love often appear to be “spaced out.” Or maybe, as the study’s authors suggest, when a person decides he or she is in love, critical thought to assess the loved one’s character is no longer considered to be necessary. The “love is a drug” connection has also been noted by psychiatrist Michael Liebowitz of the New York State Psychiatric Institute, who compares passionate love to an amphetamine high. Both can create a mood-enhancing giddiness, and withdrawal of either can cause anxiety, fear, and even panic attacks. Indeed, the body releases a host of chemicals when a person first falls in love—dopamine, norepinephrine, and especially phenylethylamine, or PEA, which is considered a close cousin to amphetamine. The “natural high” caused by these brain chemicals, unfortunately, does not last forever. Liebowitz believes that is why some people, whom he calls “attraction junkies,” move from relationship to relationship seeking their next “love high.”