💓 When we are falling in love, chemicals associated with the reward circuit flood our brain, producing a variety of physical and emotional responses—racing hearts, sweaty palms, flushed cheeks, feelings of passion and anxiety. Levels of the stress hormone cortisol increase during the initial phase of romantic love, marshaling our bodies to cope with the “crisis” at hand. As cortisol levels rise, levels of the neurotransmitter serotonin become depleted. Low levels of serotonin precipitate what Richard ⁠ Schwartz, a Harvard Medical School (HMS) professor, described the “intrusive, maddeningly preoccupying thoughts, hopes, terrors of early love”—the obsessive-compulsive behaviors associated with infatuation.⁠ ⁠ Being love-struck also releases high levels of dopamine, a chemical that “gets the reward system going,” said Jacqueline⁠ Olds, also a Harvard Medical School (HMS) professor. Dopamine activates the reward circuit, helping to make love a pleasurable experience similar to the euphor...