My love is as a fever, longing still
For that which longer nurseth the disease,
Feeding on that which doth preserve the ill,
The uncertain sickly appetite to please.
My reason, the physician to my love,
Angry that his prescriptions are not kept,
Hath left me, and I desperate now approve
Desire is death, which physic did except.
Past cure I am, now reason is past care,
And frantic-mad with evermore unrest;
My thoughts and my discourse as madmen's are,
At random from the truth vainly express'd;
For I have sworn thee fair and thought thee bright,
Who art as black as hell, as dark as night.
~ Sonnet 147, William Shakespeare
The pursuit of romantic love is a greater driving force than the sex drive, according to Rutgers University anthropologist Helen Fisher, who studies the neuroscience of love. As she describes it, symptoms of love are indeed quite powerful:
Romantic love begins as an individual comes to regard another as special, even unique. The over then intensely focuses his or her attention on this preferred individual, aggrandizing the beloved's better traits and overlooking or minimizing his or her flaws. Lovers experience extreme energy, hyper activity, sleeplessness, impulsivity, euphoria, and mood swings. They are goal-oriented and strongly motivated to win the beloved. Adversity heightens their passion [ . . . ] They reorder their daily priorities to remain in contact with their sweetheart , and experience separation anxiety when apart. And most feel powerful empathy for their amour; many report they would die for their beloved.
In fact, love can affect your brain like an addiction. When love is reciprocated it's a constructive addiction, while rejection of love is a destructive addiction. It's powerful effects have shaped and been shaped by evolution, and - Fisher argues - have even helped drive the development of human culture.
Here's an interesting lecture at UC San Diego where Fisher talks about the evolution and neuroscience of romantic love and the development of poetry and art (20 minutes):
If you are interested in more, also check out Fisher's 2008 TED talk about the brains in love (16 min.):
Happy Valentine's Day!
Fisher HE et al. "Reward, Addiction and Emotion Regulation Systems Associated With Rejection in Love" J. Neurophysiol 104: 51-60 (2010) (free pdf)
Fisher H "The Drive to Love: The Neural Mechanism for Mate Selection" in The New Psychology of Love, 2nd Edition. RJ Sternberg and K Weis (Eds.) New Haven: Yale University Press (2006) (free pdf)
Fisher HE et al. "Romantic love: a mammalian brain system for mate choice" Phil Trans R Soc B 360: 2173-2186. (2006) (free pdf)