Donatella Marazziti, a professor of psychiatry at the University of Pisa in Italy has studied the biochemistry of lovesickness. Marazziti has done studies exploring the similarities between love and obsessive-compulsive disorder. Marazziti and her colleagues (1999) did an experiment and compared the lovers’ serotonin levels with those of a group of people suffering from Obsessive Compulsive Disorder (OCD) and another group who were free from both passion and mental illness. The main finding of the study was that subjects who were in the early romantic phase of a love relationship were not different from OCD patients. She found out that levels of serotonin in both the obsessive’s blood and the lovers’ blood were 40 percent lower than those in her normal subjects. The study suggested that love and obsessive-compulsive disorder could have a similar chemical profile and love and mental illness may be difficult to tell apart.
Marazziti, D., Akiskal, H. S., Rossi, A. and Cassano, G. B. (1999). Alteration of the platelet serotonin transporter in romantic love. Psychological medicine, 29(3),741-5.