Tender love maketh greatest show of blossoms, but tried love bringeth forth sweetest juice. People caught up in the intense passion of spring love often report feeling as though they are floating, they feel like they are on a record high. Such reactions may have a basis, as least in part, in brain chemistry. The initial elation and the energizing high of excitement, giddiness, and euphoria characteristic of passionate love are a result of surging levels of three key brain chemicals, called neurotransmitters, that allow brain cells to communicate with each other.

The neurotransmitters, which include norepinephrine, dopamine, and especially phenylethylamine (PEA), are chemically similar to amphetamine drugs, and thus they produce amphetamine-like effects such as ecstasy, giddiness, and elation. When we meet someone who is attractive to us, the whistle blows at the PEA factory. Unfortunately, particularly from the perspective of people who are love drunk, the amphetamine like high associated with new love typically do not last—perhaps in part because the body eventually develops a tolerance for PEA and related neurotransmitters just as it does for amphetamines.

With time, our brains may simply be unable to keep up with the demand for more and more PEA to produce love’s special kick. Thus the highs we feel at the beginning of a relationship eventually diminish. This observation provides a plausible biological explanation for why passionate or romantic love is short-lived. Another parallel to amphetamine use, is the anxiety, despair, and pain that follow the loss—or even potential loss—of a romantic love relationship are similar to what a person addicted to amphetamines experiences during drug withdraw. In both cases, the loss of mood—lifting chemicals results in a sometimes protracted period of emotional pain. Love is a poison and by poison must be maintained.