How Well Do We Understand Neuromodulation?

Serotonin is a powerful neuromodulator that contributes to feelings of elevated mood, well-being, and overall happiness. Low serotonin levels and activity reduction is often an indicator of psychiatric disorders such as depression, anxiety, bipolar depression, and other mental diagnoses. Though antidepressants such as selective serotonin reuptake inhibitor (SSRI) drugs are considered a valuable form of treatment in the psychiatric world, the positive impacts of drugs that are classified as SSRIs and the way they are marketed in the pharmaceutical world are widely exaggerated and problematic. Though SSRI drugs such as Citalopram, Sertraline, and Fluoxetine have been successful for many patients suffering from depression, there is a lack of scientific understanding on why these drugs work. Neuromodulators are defined as brain chemicals that modify neuronal dynamics, excitability, and synaptic function.

 According to Crockett's article, SSRIs are known to enhance serotonin function by blocking its reuptake and prolonging its effects on postsynaptic receptors. Psychiatrists have grown comfortable and accustomed to the idea that SSRIs are undoubtedly the best form of treatment by restoring serotonin levels to normal and being a remedy for chemical imbalances. In Crockett's article, the effects of an SSRI known as Citalopram are studied on deontological moral judgments in multiple domains including harm and care, empathy, punishment, and fairness and reciprocity. Mary J. Crockett and her team of researchers began their study on participant's judgment on the moral permissibility of harmful actions, which is observed in three different scenarios. On November 5th, Dr. Joe Vukov from Loyola University Chicago gave a presentation elaborating on Molly Crockett’s scientific study, Neurochemical Modulation of Moral Judgment and Behavior. Dr. Vukov expresses how moral sentiments and judgments are influenced by neuromodulators, specifically serotonin’s effects when it is either enhanced or depleted. Serotonin was the chosen neuromodulator in this study due to its flexibility in control of behavior (Crockett, p. 237). Yet, Crockett’s study ultimately proves that neuromodulator levels are extremely difficult to measure in humans, as there is no scientific consensus on what constitutes healthy levels of serotonin in an individual. Healthy levels of serotonin cannot simply be defined by SSRIs since abnormal neural chemistry may persist in individuals. Environmental and other outlying factors may be a causation for this.

David Healy, a professor of psychiatry at Bangor University in Wales and author of Let Them Eat Prozac, further supports this notion and emphasizes that the “link between serotonin and depression is a ‘myth’ that continues to be perpetrated by the pharmaceutical industry" (Sifferlin, 2015). In addition, Dr. Victor I. Reus, a professor in the department of psychiatry at the University of California, San Francisco, illustrates that though there is no doubt that SSRIs work: “we don’t have a comprehensive and holistic understanding of why they work” (Sifferlin, 2015). Though serotonin is recognized for monitoring various social behaviors, regulators used to normalize serotonin levels, SSRIs, are not well understood and impact individual moral behavior and judgment in complex ways. While Crockett’s article proposes the idea that there is a lack of scientific evidence on the neuromodulator serotonin and its influence on individual judgment, the article “Is the Link Between Depression and Serotonin a Myth?” also highlights the idea that SSRIs may have potential drawbacks when used as a treatment for mood disorders.

Serotonin’s influence on deontological moral judgments in the domain of harm and care was studied and participants' judgment on the moral permissibility of harmful actions was observed in three different scenarios. In the first case, the drug citalopram, a selective serotonin reuptake inhibitor, was administered on participants. Next, participants received a noradrenaline reuptake inhibitor drug called Atomoxetine. In the third scenario, participants received a placebo pill. The effects of Citalopram, Atomoxetine, and placebo on judgments were compared in three different scenarios: neutral scenarios that contained no moral content, “personal” moral scenarios in which harmful actions were emotionally salient, and “impersonal” moral scenarios in which harmful actions were not emotionally salient. While neutral and impersonal scenarios observed no differences across treatments on judgments, personal scenarios seemed to increase harm aversion. This was because participants were more deontological, indicating that they were less likely to induce harm on one individual to save many other individuals. Next, researchers also studied how drug effects interacted with individual differences by splitting participants into low and high empathy groups. The researchers discovered that there is no effect of citalopram on judgments in the low-empathy group, yet there is a great effect in the high empathy group.

Next, researchers studied how serotonin affects morality in the aspect of fairness and reciprocity through data collection using the Ultimatum game, studying how costly punishment can be affected by manipulation of the serotonin system. Researchers studied the effects of enhancing serotonin function with citalopram on costly punishment in the Ultimatum Game. While comparing the effects of Citalopram and Atomoxetine, researchers discovered that citalopram, a selective serotonin reuptake inhibitor, influenced decision-making while Atomoxetine, a noradrenaline reuptake inhibitor, did not affect decision-making. The effects of Citalopram were strongest in participants with high empathy; citalopram reduced the rejection of unfair offers producing the opposite effect to acute tryptophan depletion. In addition, brain regions associated with motives for revenge were studied in depth through neuroimaging study. Scientists observed that there is evidence that actively delivering punishment has motivational value. When people were punished for unfair behavior, there was an increase in activity in the dorsal striatum. These scientific findings suggest that if depleting serotonin increases punishment behaviors by enhancing the motivational value of punishment, then we should observe that serotonin depletion increased activity in the striatum in individuals who punish others. Consequently, scientists observed that serotonin depletion increased activity in the dorsal striatum during punishment, and individual differences in the neural effects of depletion were correlated with individual differences in the behavioral effects of depletion.

Evidence from Sifferlin’s article suggests that each individual's neural chemistry is more complex, and providers must place individual attention on each patient to understand which method of treatment is most effective for mood disorders such as depression. Alternatives to SSRIs may be used, such as older tricyclic antidepressants which may have fewer effects of impairment in one’s daily life. Simultaneously, Dr. Vukov’s presentation on Crockett's article emphasizes that neuromodulation on moral judgment and behavior is contingent on factors such as stress, each individual has complex neural chemistry influencing their decision making and moral judgment, and individuals don’t recognize when their actions may be morally impermissible or harmful.

Dr. Norman Sussman, a professor in the department of psychiatry at New York University, states "Some of the older drugs may work better with fewer quality- of-life-impairing effects.” Ultimately, I believe that psychiatrists and scientists must look at alternative options rather than constantly relying on SSRIs for treatment. Some psychiatrists don't even allow patients to elaborate on feelings and problems they are experiencing in their personal lives. Instead, they make a hasty judgment to prescribe their patients with antidepressants/ SSRIs such as Prozac, Zoloft, etc. It is important to take a more holistic approach to avoid potentially harmful side effects that SSRIs may have. Every individual has different neural chemistry, and the solution is not as simple as SSRIs restoring abnormal serotonin levels. SSRIs are also often overprescribed. Healy describes how there is no doubt that serotonin plays a role in the treatment of depression and that it is "not irrelevant"; yet the problem persists with the idea that "the market boom of SSRIs raises questions about why physicians would put aside clinical trial evidence in place of ‘plausible but mythical’ accounts of biology.”

Evidence from Crockett's study indicates that moral judgments are not fixed, but are contingent on neuromodulator levels and stress. Neuromodulator levels are constantly changing, so it is difficult to see precisely what the influences of this flux are on our moral judgments and behavior in real-time. This suggests we cannot be fully aware of what is guiding some of our morality, and that it is sometimes being guided by neuromodulators that do not seem relevant to morality. Determining which state is “neutral” for establishing a neutral ethical baseline is a short value judgment that would be influenced by the same neurochemical factors. Crockett’s research suggests that our moral judgments, including those about what might be normal functioning or healthy moral behavior, are largely influenced by our neurochemicals. If this is the case, then perhaps we should not be as confident in our normative evaluations, which in turn seems to suggest we should not be as confident in our evaluations of what counts as “correct” morality of normal behavior. Sifferlin’s article leads us to wonder about the justification of the idea of norms that underlie the decision to treat people in the first place. In the coming years, it will be crucial to systematically investigate these questions and debate their significance for morality. The idea of a neutral physiological state can only arise with the insertion of moral judgment because there is no scientific basis for it.

    
 

Works Cited

Crockett, Molly J. “Morphing Morals.” Moral Brains, 2016, pp. 237–245.,

doi:10.1093/acprof:oso/9780199357666.003.0011.

Sifferlin, Alexandra. “The Link Between Serotonin and Depression Is a Myth, Psychiatrist Says.” Time, Time, 21 Apr. 2015, time.com/3829565/is-the-link-between-depression-and-serotonin-a-myth/.