"Around the world, people love. They sing for love. They dance for love. They compose poems and stories about love. They tell myths and legends about love. They pine for love. They live for love. They kill for love. And they die for love" ("The Brain in Love" 00:01:36-00:01:52). Indeed, anthropologists have found romantic love to exist within 170 societies; there is not a society that exists without love ("The Brain in Love" 00:01:58-00:02:05). When a person is in romantic love with a significant other, and the relationship is going well, love can be a happy experience. However, when the relationship is no longer going well, love is not always a happy experience, and many times, this can lead to divorce. In a study done by Utah State University, researchers reported that, as of 2016, first-time marriages ended in divorce 49% of the time, and, with each subsequent marriage, the divorce rate increased. These numbers mean that every 13 seconds, there is a divorce in the United States ("Divorce" 1; Hawkins and Fackrell 42). Though there exist many factors as to why a couple may choose to end a relationship—too much arguing, marrying too young, unrealistic expectations, lack of equality, and abuse—the most common reasons as to why marriages end in divorce are lack of commitment and irreversible damage caused by infidelity ("Divorce" 1; Hawkins and Fackrell 44; Lewandowski 1). Furthermore, though there exist many factors as to why a person in a relationship may choose to be unfaithful—including individual, relationship, situational, and social factors—I propose that the increase in depression diagnoses combined with the increase in prescribed antidepressants, such as selective serotonin reuptake inhibitors (SSRIs), may be a largely unrecognized and leading cause of this problem. In this paper, I will identify the three primary neural systems involved in mating and reproduction: the sex drive, romantic love, and attachment; I will discuss the effects of general and SSRI antidepressants on the neural systems; and finally, I will demonstrate how SSRI antidepressants may be an unrecognized and leading cause of infidelity, resulting in an increased divorce rate.

Three Neural Systems Involved in Love

Researchers and neuroscientists alike currently believe basic human emotions and motivations are derived from distinctly specific areas of neural activity, and these areas of neural activity evolved to enable survival and reproduction in natural selection (Fisher and Thomson 246). In her article, "Lust, Attraction, and Attachment in Mammalian Reproduction," anthropologist Helen Fisher, a leading scientist in the field of romantic love, notes that among these primary areas of neural activity are three emotional and motivational systems for mating and reproduction: the sex drive, romantic love, and male-female attachment (Fisher 27).

The sex drive includes the craving for sexual gratification and has evolved primarily to motivate individuals to "put themselves out there" and seek sexual relationships with a wide range of mating partners (Fisher 27-30). The sex drive overlaps with romantic love, but the two systems remain distinct in their fundamental characteristics. Romantic love is characterized by "intense energy, focused courtship attention, ecstasy, mood swings, sexual possessiveness, emotional dependency, obsessive thinking about the beloved, craving for emotional union with the beloved, and intense motivation to win this preferred mating partner" (Fisher and Thomson 246). These characteristics essentially suggest that romantic love encompasses the elation and obsession stage of early love, as romantic love is primarily associated with increases in the neural circuits for dopamine in the brain. The ultimate difference between the sex drive and romantic love is that the neural system associated with romantic love evolved primarily to motivate individuals to "focus on one individual at a time" and to choose a specific mating partner, thereby conserving mating time and energy (Fisher 31-29). Finally, male-female attachment is characterized by "feelings of calm, security, social comfort, and emotional union with a long-term mating partner" (Fisher and Thomson 247). These characteristics essentially suggest that partner attachment is primarily associated with increases in the neural circuits for oxytocin and vasopressin in the brain, and has evolved primarily to motivate individuals to tolerate the human being they experience romantic love with long enough to carry out parental duties if children are involved (Fisher 39-41).

In this paper, I will be focusing in-depth on the romantic love system, primarily due to the fact that the romantic love system is directly associated with increases of dopamine, the definitive neurotransmitter involved in depression, in the brain. Though my argument draws heavily from the foundational studies conducted by Helen Fisher, who continues to be the leading researcher in exploring romantic love, I will also draw from other scholarship that suggests links between SSRI antidepressants and a decrease in feelings of romantic love for a significant other.

To investigate the neural pathways associated with romantic love, Fisher, Art Aron, Lucy Brown, and other researchers investigating this topic placed thirty-two individuals who were "madly in love" into a functional MRI (fMRI) brain scanner. Seventeen of those individuals were "madly in love" and their love was reciprocated, while fifteen of those individuals were "madly in love" and their love was not reciprocated: they had just been dumped. During the study, the test subjects were asked to lie down in the fMRI machines, and their brains were scanned while they looked at a photograph of their sweetheart and then looked at a neutral photograph, with a distraction task in between pictures. The purpose of this methodology was to examine the brain when it was in its heightened state (while looking at the photograph of the significant other) and to examine the brain when it was in its resting state (while looking at the neutral photograph) (Fisher and Thomson 249-251).

In Fisher's first study of individuals who were happily in love, activity was found in a small factory area near the base of the brain called the ventral tegmental area. In this area, activity was found in A10 cells, which are responsible for creating dopamine, a natural stimulant, and dispersing it to various brain regions to create a positive mood in the individual. Because the ventral tegmental area creates and disperses dopamine, it is part of the brain's reward system, which is associated with wanting, motivation, focus, and craving. In fact, the ventral tegmental area also becomes active while experiencing a rush from a drug like cocaine (Fisher and Thomson 249-251). However, romantic love is a much more deeply personal experience than a cocaine high—romantic love is an obsession. It possesses the individual. The individual loses their sense of self, unable to stop thinking about the other human being. And this obsession may only grow worse when experiencing rejection.

In Fisher's second study of individuals who had recently been dumped, activity was found in three brain regions. One of these brain regions is the exact same region associated with intense romantic love (Fisher 35-37). A common problem for many who experience an unwanted breakup is the desire to forget about the other human being and carry on with life; however, because there is activity in the brain region associated with intense romantic love, instead of forgetting about the other person, the brain tends to want them more. The second of these brain regions, at the core of the nucleus accumbens, is associated with calculating gains and losses. It is also the brain region that becomes active when one is willing to take risks for these potentially large gains and losses (Fisher 35-37). Another common problem for many who experience an unwanted breakup is the tendency to obsess over what went wrong in the relationship, and, because of the nucleus accumbens, the tendency to calculate losses. The third and final brain region is associated with deep attachment to another individual (Fisher 35-37). This evidence demonstrates why people suffer so much when they part with a significant other. Rejection often brings overwhelmed feelings of a lost romantic love, and. because of this third brain region, the addition of deep attachment to the other individual.

From this experiment, Fisher learned that romantic love is one of the most powerful emotions on Earth. But romantic love is not only an emotion; it is a neurological drive, a basic mating drive that enables a person to focus mating energy on just one partner at a time, to conserve mating energy, and to start the mating process with one, specific individual (Fisher and Thomson 268). Fisher also learned that not only is love a neurological drive; it is involved in an interrelated set of involuntary brain systems. And when one of these brain systems is affected, the other brain systems are also adversely affected (Fisher and Thomson 269).

Though there is overlap between all three neural systems, they are not always connected to each other. For instance, an individual may feel deep attachment to a long-term partner, while also feeling intense romantic love for another person and sex drive for a different person entirely (Fisher and Thomson 246). Thus, as human beings, we are physically and physiologically capable of loving more than one person at a time, sometimes without consciously knowing so. I hypothesize that, because the mechanisms of these three neural systems allow us to love more than one person at a time, we are also more biologically inclined to commit acts of infidelity and adultery. Specifically, in the presence of antidepressants, such as SSRIs, our propensity to commit acts of infidelity is increased, because while SSRIs regulate functions in the brain, they also bring about side effects, such as suppressed feelings of romantic love and decreased sex drive toward significant other -- two side effects that may lead to the onslaught of future infidelity and adultery.

Overview of Depression and Antidepressants

According to Margaret Alic, a writer for the Gale Virtual Reference Library, depression is a common mental illness in which people experience feelings of intense sadness for long periods of time, often without any reasoning. In addition to experiencing these feelings, people may find it difficult to function from day to day, and, as a result, they may be reluctant to participate in daily activities that they normally would otherwise (Gurung 653). Numerous factors have been found to influence or trigger the onset of depression; however, biology is generally accepted to be the most common factor, and it often involves the role of neurotransmitters in the brain.

In the brain of a person who does not have depression, there are pre-synaptic neurons and post-synaptic neurons in close proximity to each other. Between the pre-synaptic and post-synaptic neurons is a small gap, known as the synapse. As nerve impulses transfer chemical messages down the axon terminal to the nerve ending of the pre-synaptic neuron, the neurotransmitter serotonin is released into the synapse. Once serotonin is dispersed into the synapse, it will either bind to serotonin receptors on the post-synaptic neuron, or some of it may be re-absorbed by serotonin reuptake transporters on the pre-synaptic neuron. Because serotonin is a neurotransmitter that is involved in the overall happiness levels of a person, when enough serotonin is received by the post-synaptic neuron, the chemical message can then move forward and may have positive effects on a person's mood. In the brain of a person who has depression, too little serotonin is released from the pre-synaptic neuron, and too little serotonin is taken up by the post-synaptic neuron. As a result, the chemical message transmitted by the pre-synaptic neuron to the post-synaptic neuron cannot move forward and may have negative effects on a person's mood, more times than not resulting in symptoms of depression (Alic 285-286; Gurung 652).

Antidepressants have been chemically designed to relieve symptoms of depression. There are many types of antidepressants, and they can be organized into classes based on the severity of the depressive state of the individual. However, the most commonly prescribed antidepressants are known as selective serotonin reuptake inhibitors (SSRIs). SSRIs function by reducing or blocking the reuptake of serotonin by the pre-synaptic neuron. In the brain of an individual who takes SSRI antidepressants, the SSRI will travel to the synapse between the pre-synaptic and the post-synaptic neurons, and it will attach itself to the serotonin reuptake transporters on the surface of the pre-synaptic neuron. Eventually, it will block the serotonin from being taken back up into the pre-synaptic neuron. In doing this, serotonin levels within the synapse will increase, leaving more serotonin free to stimulate the receptors on the post-synaptic neuron, thereby having positive effects on a person's mood and leaving the person feeling happy (Alic 285-286; Gurung 652).

In the United States, over 100 million prescriptions for antidepressants are written every year, and a large number of these prescriptions are written specifically for SSRIs, such as Prozac, Paxil, and Zoloft (Alic 284; Rose 125). Though these antidepressants increase the levels of serotonin in the brain, they simultaneously suppress the neural circuit for dopamine (Fisher and Thomson 269). Dopamine is a neurotransmitter involved in feelings of romantic love. When the neural circuit for dopamine is suppressed, the circuits associated with elation, obsessive thinking and feelings of romantic love are suppressed as well. And therefore, if these drugs work properly, the romantic love system is effectively compromised (Fisher and Thomson 269).

As mentioned earlier, when one of these brain systems is compromised, the other two brain systems are affected, as well. Suppressing feelings of romantic love may lead to a decrease in the sex drive, and when the sex drive is decreased, the ability to experience orgasms is decreased as well. Further, without the ability to experience orgasms, the decline in transmission of oxytocin and vasopressin may further complicate an individual's ability to feel attached to their significant other, which may suppress the partner attachment brain system and result in the total loss of love interest for a significant other.

Conclusion

To conclude this paper, I would like to propose a case study. A forty-three year old, married, white, female with anxiety, bipolar disorder, recurrent depressions, and obsessive-compulsive disorder was first administered Prozac, an SSRI antidepressant, at relatively high doses for her recurring depression when she was twenty-two years old. Two years after she was first administered Prozac, this woman happily married. Over the next fifteen years, this female was prescribed three different SSRI antidepressants to treat her ongoing feelings of anxiety and depression, but ultimately, this woman and her husband divorced after seventeen years of her taking antidepressants, due to acts of infidelity by the woman.

After the divorce, the female began experiencing increased extreme bouts of anxiety, so she visited a physician, but not the one who originally prescribed her to take Prozac. When asked about side effects, the woman said she had none. The woman then recalled her husband had asked her multiple times during the previous fifteen years to visit a psychologist to see if the various medications she was taking at the time were working properly. Her husband noticed her mood swings were becoming more volatile, and her sex drive dramatically changed. When she was asked specifically about any sexual side effects that she may have experienced from Prozac or other SSRI antidepressants she took, she was not certain about the answer, and asked that the possible side effects be explained. Once the possible side effects were explained by this new doctor, the female acknowledged that she did have sexual side effects, but that she had not considered them to be effects of the drug at the time: she had attributed them to be effects of problems and stress within her relationship. During her appointment, the female explicitly stated, "Over time, I just started falling out of love with my husband. I cannot explain it; it just happened."

The woman in this case study just so happens to be a close family friend of mine. When attempting to explain to me why she decided to have an affair, I never believed her justification was sufficient enough to explain her actions towards her husband and her family. However, after delving further into this topic, I now believe her justification to be honest and true. In looking at the various precautions and side effects listed by Margaret Alic in her online encyclopedia entry, sexual side effects are highlighted as the most common. Among these side effects are increased, or more often, decreased sexual interest, difficulty reaching orgasm or ejaculation, and impotence, or sexual incapability (Alic 289). Therefore, I now understand that even though the woman and husband experienced many problems in their relationship, one of the primary reasons the woman lost interest in her husband and committed an act of infidelity was due to her usage of Prozac and other SSRI antidepressants over a prolonged period of time.

Though taking SSRI antidepressants was largely necessary for the woman to help treat her mental illnesses, according to Harvard Medical School psychiatrist Joseph Glenmullen, approximately 75% of all patients on antidepressants, such as SSRIs, are "needlessly on these drugs" (Fisher 270). Physicians who prescribe SSRI antidepressants, such as Prozac, and patients who intend to pursue these drugs should keep in mind the largely unrecognized, and possibly destructive, effects of these medications in terms of their ability to love a long-term partner, especially if they are taken without the oversight of a psychiatrist.

Because SSRI antidepressants increase levels of serotonin, while suppressing levels of dopamine, feelings of happiness remain, but feelings of romantic love subside. Because the individual is no longer in love with their partner, the couple may experience difficulty and strain in the relationship, and, depending on the duration of the strain without treatment, one or both partners may feel the only healthy option is to separate. Therefore, antidepressants taken without supervision and without the care of loved ones to support treatments are another largely unstudied factor in the increasing infidelity and divorce rate.

Until pharmaceutical scientists create a new antidepressant drug that increases levels of serotonin in the brain in addition to increasing levels of dopamine in the brain, we will never know just how many divorces are aided in part by side effects of SSRI drug therapy treatments. And until psychiatrists begin fully explaining the sexual side effects of SSRI drug therapy treatments in addition to recommending marital therapy to married patients taking SSRI antidepressants, many healthy marriages will continue to be vulnerable to the unnecessary prescribing of these romantic love-compromising medications.

Author

Abigail Brunory

Abigail Brunory is from Carmel, Indiana, a suburb just north of the capital city, Indianapolis. She currently resides in Pasquerilla West Hall, and is a Biological Sciences major with a concentration in Medical Neurobiology. Following graduation, she hopes to attend graduate school and conduct research in the neuroscience field. "The Unrecognized Marriage-Killing Effects of SSRI Antidepressants" was inspired by a particularly impactful experience from her childhood, where she experienced the impacts of infidelity on a marriage first-hand. This paper is an attempt to better understand her childhood experience and cope with the events that occurred. Abigail would like to thank her high school English teacher, Mrs. Jill McGrath, for helping her find her passion and her voice as a writer. She would also like to thank her Multimedia Writing and Rhetoric Professor, Dr. Erin McLaughlin, for her support and guidance in the writing process of this paper.