Thirty years ago, when Prozac had just become available, I prescribed it to a patient with seriously disabling depression. My patient responded promptly, and soon he had a new report to make. He was more poised and socially at ease than he had ever been. He said the medication had made him “better than well.”
In the United States, Prozac was the first of a group of antidepressants called selective serotonin re-uptake inhibitors (SSRIs) that alter the way the brain handles serotonin. In addition to treating depression, they seemed to make certain people more assertive or less curmudgeonly than they had ever been before. Soon more of my patients said the medication made them feel more confident. Most considered the change unreservedly for the good. Others found it eerie and came off the drug. I wrote about effect, first in essays for colleagues and then in my 1993 book, Listening to Prozac.
In recent years, skeptics have questioned antidepressants’ ability to do their main job, treating major depression. Whenever a professional paper along these lines appears, trolls on the web will challenge me: If the drugs don’t get people well, how can they get them “better than well?”
But years of research have largely confirmed the idea that I floated in the 1980s: in the course of depression treatment, antidepressants affect personality.
For instance, in 1999, Swedish researchers observed the impact of SSRIs on depressed patients treated in a general practice setting. Most improved—but the more interesting findings concerned personality traits.
The study tracked measures of socialization and social desirability and assessed patients’ levels of aggression, attachment, suspicion, and obsessiveness—25 traits in all. The authors observed: “After treatment, significant changes in the direction of normalization were seen in all scales.” The patients’ gains in sociability appeared to be independent of changes in their moods. The researchers believed that they were seeing a medication-induced shift in temperament.
This pattern has since been replicated in studies of a handful of mood disorders. Some of the trials compared the effects of the new antidepressants to those of psychotherapy, older antidepressants, or dummy pills. Every study found some version of the pattern that had appeared in my practice. On SSRIs, mood-disordered patients became more assertive and less socially inhibited.
It’s unclear whether these effects are specific to SSRIs. It’s possible that older antidepressants, such as Elavil and Tofranil, have a similar impact, one masked by their side effects. Patients who feel drugged by a medication may not report that they are also feeling more confident. Or it might be that when people recover from depression, by whatever means, they become less diffident.
Today, the major controversy about antidepressants concerns how well they actually treat major depression. I believe that they do it “ordinarily well”—that their efficacy is equal to that of most treatments used throughout medicine. Some critics disagree. But whatever the answer, the medications do appear to have a separate effect on personality.
Evidence that the two issues are separable comes from studies by researchers from the University of Pennsylvania, Vanderbilt University, and elsewhere. This team made one of the most influential contributions to the current debate, a research overview, published in JAMA. The paper suggested that antidepressants are inherently effective only in severe depression.
But looking at some of the same data, the researchers concluded that SSRIs can have a strong impact on personality. The Penn-Vanderbilt group focused on a trait called “neuroticism”—uncomfortable self-consciousness and emotional vulnerability. In patients on Paxil, the researchers noted decreases in neuroticism four to eight times as large as those in patients on placebo.
In subsequent months, patients whose neuroticism scores had dropped suffered fewer depressive episodes. Even patients who stopped treatment retained protection from depression—so long as they had first improved on Paxil. Neither placebo nor psychotherapy offered this benefit. What the antidepressant did best was to make people less fragile.
The researchers suggested that prior speculation had gotten the direction of influence wrong. It wasn’t that recovery from depression made people less neurotic or introverted. Instead, the SSRI had personality effects that altered the course of depression.
In my book, considering the effect of medication on non-severe depression, I critique the JAMA paper’s methods and dispute its interpretation of the evidence. As I read the research, and as I observe in my own practice, antidepressants can be helpful across the range of depressive disorders.
But even experts who believe that antidepressants have limited impact on depression can accept that the medications have important effects on personality.
The collection of studies on how SSRIs affect assertiveness, social ease, and other traits is not extensive. It’s still possible that researchers’ conclusions are wrong. But the findings have been fairly uniform. If anything, they indicate that changes in personality traits are more common than I had imagined.
As a practicing doctor, my impression remains that only a minority of those treated see noteworthy personality effects on SSRIs. It’s true that not every patient is comfortable with the change. But most find it liberating. As treatments for depression, SSRIs work ordinarily well—and for some patients, they also catalyze remarkable shifts in temperament and social functioning.