In recent years, there has been increasing concern about the problem of antidepressants finding their way into the environment. These drugs aren’t fully absorbed by the body and are present in human waste. Small concentrations are then flowing into rivers via wastewater treatment facilities where wildlife can be affected.
In August 2018, several media outlets reported that antidepressants were having a negative effect on the courting behavior of starlings (birds), specifically that males were singing less to females and showed signs of decreased interest.
A cursory glance of the headlines suggested that this might be the issue of antidepressants causing reduced sexual interest and disruption of normal social behaviors. Almost everyone who takes an SSRI or SNRI will be affected sexually to some degree, and these drugs can also cause emotional blunting, potentially affecting feelings of love towards a partner. But in this case, there was an unexpected twist to the story.
The media reports related to a study by Whitlock et al which noted that starlings are being exposed to antidepressants in the environment by foraging for invertebrates near wastewater treatment plants. To investigate what effect this might have on behavior, the authors ran a trial involving a group of starlings, some of which they administered with fluoxetine. The concentration wasn’t based on a therapeutic dose, but instead was in line with the low levels that these birds can be exposed to environmentally.
If the study had reported altered behavior in the birds that were exposed to the antidepressant, this might have been expected. In this case, however, it was discovered that the male starlings appeared to be less attracted to and more aggressive towards the females that had been given a small dose of fluoxetine, compared to those that were not exposed to the drug. In other words, the administration of an SSRI appeared to make the female starlings less desirable.
The authors of the study were unable to explain this finding. While the medicated females displayed increased aggressiveness on day one of the study and less aggressiveness on day two, overall this didn’t correlate with the altered male behavior. Female aggression occurred even in the non-medicated control group.
In the absence of a clear explanation, the authors discussed several possible ideas based on the known effects of antidepressants such as lethargy, changes to personality, and reduced sexual receptiveness.
It’s difficult to know why an antidepressant made the female starlings less attractive to males. However, it might be interesting to speculate as to whether a similar scenario could occur in humans. Could the use of antidepressants make men and women less desirable to a potential partner, either in terms of physical attractiveness or anything else that might hinder the ability to make an emotional connection – and if so, what specific effects might contribute to this?
The ability to smell a partner’s natural odor and their ability to smell our own is important in a relationship. Various medications can affect sense of smell in different ways. Perhaps one of the most interesting is the oral contraceptive.
A study by Roberts et al found that women’s preferences in terms of the natural odor of a potential partner changed depending on whether or not they were using contraceptive medication. While unmedicated, the women typically preferred the odor of men whose immune system was different to their own. This seems like useful natural behavior as parents with the most dissimilar immune systems can apparently produce a stronger immune system in their offspring.
But when on a contraceptive, women preferred the odor of men with an immune system that was similar to theirs. This has implications for women who begin a long-term relationship while on contraceptive medication, and who then halt the drug a few years later to start a family, and realize they are no longer attracted to the smell of their partner.
In terms of antidepressants, some people experience a reduced sense of smell (hyposmia) which could potentially impair their ability to properly smell a partner. As sense of smell also plays a significant role in a person’s sense of taste, both senses can be affected. RxISK’s recent paper on post-SSRI sexual dysfunction included some reports where a reduced sense of smell and/or taste persisted after the antidepressant had been stopped. Obviously, an antidepressant-induced hyposmia would only affect the person taking the drug. It wouldn’t make them less attractive to someone else who wasn’t on the medication.
However, a common side effect of SSRIs is increased sweating. This can lead to increased body odor, which may be particularly difficult to keep under control in warm weather. There is the added complication that if the person also has a reduced sense of smell from the drug, they may not be fully aware of the extent of their problem.
Separate from the sweating issue, there have been some instances where people have noticed an actual change in body odor following the commencement of antidepressants. If this had only been detected by the person taking the drug, it would be difficult to know whether the change in odor was real or if the drugs were producing an olfactory hallucination, or perhaps a degree of parosmia (where a smell is perceived incorrectly).
But interestingly, there have been occasions where an apparent change in natural odor has been noticed by the person’s partner who has commented that they no longer smell the same since starting the antidepressant, and they don’t feel as attracted to them as a result.
Personality and behavioral changes
Antidepressants can alter a person’s behavior and personality in a variety of ways.
One of the main effects, particularly from SSRIs and SNRIs, is emotional blunting. This not only means that a person no longer cares as much about something that is troubling them, but it can also make them not care as much about their job, their partner, their children, etc. Some people decide to stop the medication because they don’t like the abnormal flattening of their emotions or they find it disturbing that they have lost the ability to cry in sad situations. However, people often don’t realize the extent to which they are being affected until they stop the drug.
Emotional blunting can also make people less concerned about the consequences of their actions which can lead to disinhibited and risky behaviors. After coming off antidepressants, people are sometimes surprised or embarrassed about the things they said or did while on the medication.
In 2000, a randomized placebo controlled trial was run in which healthy volunteers from the administrative, medical and nursing staff at a psychiatric unit were put on antidepressants. This was a double blind study, meaning that neither the participants or trial organizers knew who was on an antidepressant and who was on placebo.
One of the male medical staff became so changed by the medication that his patients noticed he was acting out of character, leading one of them to ask, “what’s he on?”
A female participant became disinhibited and very needy of people’s time and company. She told her life story to a colleague who she didn’t know very well. She also began impulsively spending more money than normal, and did a number of other things that she would later regret, including some that she was reluctant to divulge.
Another participant reported feeling a lack of fear and being unconcerned about the consequences of her actions. This was demonstrated when she stopped her car in moving traffic and grabbed and threatened a youth at the side of the road who had been making obscene gestures at a junction. Her behavior was completely out of character and terrified her mother who was a passenger in the car.
Both of the female participants mentioned above went on to become suicidal. Interestingly, one of them didn’t stop taking the antidepressant even though she was told to stop on more than one occasion by the trial organizers. In the end, the drug had to be physically taken away from her.
For anyone who wants to read more about the study, it is available here. There is also a more extensive account in chapter 7 of the book, Let Them Eat Prozac.
A fairly common side effect of antidepressants is dry mouth. While this might not seem like a major problem, it can make you more prone to bad breath, and in the longer term, tooth decay. SSRIs can also cause teeth grinding which can result in significant damage. If you were to lose any teeth, your options may be limited as a 2014 study from Wu et al and a subsequent study from the University of Buffalo have reported that antidepressants may increase the failure rate of dental implants.
Another side effect that some people experience is significant weight gain. This can happen gradually which means that people often don’t realize the drug is causing the problem. Regardless of whether or not you think a person’s weight dictates their attractiveness, the point is that if they’re unhappy about having gained a lot of weight, it can affect their self-esteem which in turn can influence how they act around others.
In addition to some of the dramatic personality and behavioral changes described earlier, antidepressants can also have more subtle effects on behavior. For example, a healthy volunteer study by Jonassen et al discovered that a single dose of citalopram caused participants to display reduced eye contact when viewing images of faces. Participants also exhibited an increased number of saccades (small, quick movements of the eyes). The authors concluded: “These results suggest that the SSRI administration affects the perceptual processing of face stimuli.”
Perhaps the most obvious group of problems that can potentially impact relationships are sexual side effects. These can include reduced genital sensation, lowered libido, erectile or lubrication dysfunction, orgasm disorders, and other difficulties.
Antidepressants can sometimes also cause a range of cognitive issues including difficulty concentrating, memory problems, and an inability to think clearly. They are sometimes referred to collectively as “brain fog” and may worsen or become noticeable for the first time during withdrawal. These issues rarely show up on standard psychological testing, meaning that those affected can find it almost impossible to obtain objective evidence of their impairment, even though it may be having a profound impact. Like personality and behavioral changes, cognitive impairment can influence how you interact with other people and how well you make a connection.
Noticing a difference
Depending on the person, it’s sometimes possible to notice if they are taking an antidepressant, particularly if you knew them before they started the drug and can tell that something is different about the things they say or the way they act. In others, it can be more difficult to recognize. People sometimes comment that a person, who they may not know is on an antidepressant, is a little strange though they can’t quite explain why. They might seem a little spaced out or in a world of their own, or just have a certain quality to them that seems slightly medicated.
You might have encountered a situation where you watched a celebrity being interviewed on TV and noticed there was something a little unusual about them – and later discovered they are taking antidepressants.
Perhaps there is something about this very subtle change that was detected by the male starlings. Maybe they instinctively knew that something was different about the female birds on fluoxetine, and were able to perceive changes in behavior that wouldn’t have been noticeable to observers.
In human terms, it’s difficult to say whether the effects of an antidepressant would be off-putting to a potential partner, and to what extent. There are certainly plenty of people on antidepressants who are in relationships. A care-free attitude and a degree of disinhibition may be viewed by some as attractive qualities, although sexual dysfunction and decreased empathy are probably less desirable in a partner.
A major issue is that many of the effects produced by antidepressants can sometimes remain indefinitely after the drug is stopped including emotional blunting, cognitive impairment, sexual dysfunction, and many more. Problems like dry mouth and teeth grinding can also leave permanent damage.
Mirror, mirror, on the wall…
If there are any psychologists reading this who are looking for an interesting idea for a research project, it would be fascinating if someone attempted to run a similar experiment to the starlings study, but in humans.
Speculating on what this might look like, it could perhaps be some kind of dating experiment involving a group of men who haven’t been exposed to SSRIs, and a group of women – half of whom are given an SSRI for the duration of the study. Each male participant would be paired up with each female in turn and sent on a date. The male participants could then rate which females they connected with the most. Obviously, this experiment could also be run with the sexes reversed.
An alternative might be some kind of speed dating event, although spending only a few minutes together might not be long enough to notice some of the more subtle behavioral changes that antidepressants can cause.
It would be preferable to use healthy volunteers rather than recruiting people who are already using antidepressants, as the latter would only result in applications from those patients who are doing well on the drugs. Those dealing with sweating issues, lethargy, excessive weight gain, akathisia, and other problems probably wouldn’t volunteer for a dating experiment.
Even without exploring the issue of attraction and courtship, it would be interesting to put a group of men and women together for a few hours and see if they could tell who was on an antidepressant and who wasn’t.