SSRI stands for ‘Selective Serotonin Reuptake Inhibitor’ and the group includes drugs such as Prozac (fluoxetine), Seroxat (paroxetine) and Zoloft (sertraline) which all increase the availability of the neurotransmitter serotonin in the synapse – the chemical junction between neurons.
Despite the (somewhat misleading) use of the word ‘selective’ in the title, these drugs also affect many other types of neurotransmitters to varying degrees – of which dopamine is one.
Fisher maintains that as attraction, desire and sexual pleasure are known to involve dopamine circuits in the brain, these drugs interfere with relationship formation.
This dopamine deficit affects people in a variety of ways, according to Fisher and her research partner, Virginia-based psychiatrist J. Andrew Thomson, Jr. Singles using antidepressants may have a harder time meeting people, because their natural sexual response is dampened. Some researchers believe desire was designed to help people select mates who are genetically suited to them. The spark that ignites on meeting someone new is telling you something: This might be your match. When you miss those signals, your odds of finding an appropriate mate decrease.
Fisher outlines her theory in a paper published with psychiatrist J. Anderson Thomson in the recent book Evolutionary Cognitive Neuroscience.
Luckily, the paper is also available online as a pdf file if you want to see their argument in full.
As an aside, the Psychology Today article is by science writer Orli Van Mourik, who you may know from Neurontic blog.