Warning: Antidepressants May Cause Messaging Manslaughter

September 19, 2017

Neither time nor science has given pause to some attorneys who exploit the misunderstanding that surrounds the putative "criminogenic" effects of antidepressants.

Several years ago, we commented about the practice of some attorneys who exploit the misunderstanding that surrounds the putative “criminogenic” effects of antidepressants.1 Neither time nor science has given pause to the trend of condemning these widely used and beneficial medications. This legal strategy continues. Attorneys use “experts” to testify that these medications can produce all manner of illegal behaviors-from murderous rage to callous lack of empathy to manipulative criminal behaviors.

Here, we give a brief update on the research in this area, along with an illustrative criminal case that received international media attention-the case of Commonwealth v Michelle Carter-more popularly known as the “texting suicide case.”

Antidepressants as “criminogenic” agents

Approximately 13% of persons aged 12 and older take antidepressants, which makes them one of the top 3 most commonly used medications in the US.2,3 Four years ago, we reviewed the literature and found no statistically relevant evidence that antidepressant medications cause violence or criminal behavior.1

In contrast, we found reliable research that showed that antidepressants were associated with a significant decrease in lethal violence and a reduction in irritability and aggression.4-6

The relatively rare adverse effects of antidepressant-induced mania and serotonin syndrome are sometimes invoked by those who believe antidepressants are criminogenic. However, these adverse effects produce characteristic physical symptoms and mental status changes that are easily distinguishable from a criminal act committed in the absence of these phenomena. But what has the research found since our last review?

A Swedish study of medication adherence using a nationwide registry of dispensed prescriptions found that nonadherence to antidepressants appeared to elevate the risk of homicide offending, while adherence showed no association.7 Another Swedish study looked at psychotropic medications in offenders released from prison.8 The study included all released prisoners from 2005 to 2010, and rates of violent reoffending during medicated periods were compared with rates during nonmedicated periods using within-individual analyses. For this group at high risk to reoffend, antidepressants were not associated with violent reoffending.

Focusing specifically on the serotonin receptor, Crockett and colleagues9 enhanced serotonin in healthy volunteers with citalopram and contrasted its effects with both a pharmacological control treatment and a placebo on tests of moral judgment and behavior. Subjects who received citalopram were more likely to demonstrate an aversion to harming others, as well as greater prosocial behavior. Siegel and Crockett10 later analyzed serotonergic research and hypothesized that serotonin may shift social preferences in a prosocial direction.

In contrast to the abundance of studies that indicate no association between antidepressants and violence, findings from a Swedish study, from 2006 to 2009, suggest an association between SSRIs and violent crime that varied by age group.11 The study compared the rate of convictions and arrest for violent crime while individuals were taking SSRIs with the rate in the same individuals while not receiving medication. The study used age stratification to find a significant association between SSRIs and violent crime convictions for individuals aged 15 to 24; there were no significant associations for those aged 25 and older. Unsurprisingly, associations in 15- to 24-year-olds were also found for nonviolent crime convictions/arrests, nonfatal injuries from accidents, and emergency inpatient or outpatient treatment for alcohol intoxication or misuse. Nevertheless, the authors found an association between SSRIs and violent crime that varied by age group.

This study gives us the opportunity to briefly note that the problem of taking subsequence for consequence (post hoc, ergo propter hoc) is ever present-particularly in high-controversy issues. Focusing on this long-standing medical research dilemma, Pozzi and colleagues12 conducted an interpretative review of research reports from 2012 to 2014 dealing with antidepressants and suicide. They concluded that there were many methodological problems with this area of research that introduced bias and prevented reliable meta-analyses, including:

1. The presence of populations with different baseline risks

2. The application of inappropriate outcome measures for self-injury

Further complicating matters is the reality that most individuals who are treated with antidepressants are already experiencing substantial life stressors (eg, relationship difficulties, financial and personal losses, employment problems, and life transitions)-clinical risk factors for both suicide and violence.

No Prozac, no murderMurder most foul, as in the best it is. But this most foul, strange and unnatural.
      Shakespeare, Hamlet (Act 1, Scene 5)

On the morning of July 13, 2014, the body of 18-year-old Conrad Roy III was found in his truck, parked in the lot of the Fairhaven, Massachusetts, K-Mart. What appeared initially as a tragic suicide by carbon monoxide poisoning would later unfold into something strange and foul. It would end with a conviction of involuntary manslaughter for Roy’s girlfriend, 17-year-old Michelle Carter. Soon after Roy’s death, authorities questioned Carter, who expressed grief over the loss and even helped organize a softball fundraiser in Roy’s honor.

Later, investigators recovered a string of text messages between Roy and Carter leading up to the time of Roy’s death. The unnatural twist was that Carter’s text messages clearly encouraged and pressured Roy to kill himself, even in the midst of his depressive ambivalence. While Roy struggled with the decision to end his own life, Carter texted him words of encouragement such as, “No more thinking, you need to just do it,” and, “It’s time babe, you know that . . . you gotta do it. You’re ready, you’re determined. It’s the best time. . . . You can do this.” And so, Roy did as his girlfriend so persistently suggested.

A grand jury found enough evidence to charge Carter with “wantonly and recklessly” assisting Roy’s suicide. The case sparked significant controversy and became known in the media as the “texting suicide case.” Issues such as the first amendment right to free speech were debated, as well as the contours and limits of crimes committed via texting. When the case, , went to trial, other disturbing details were revealed. Not only had Carter used text messages to persuade Roy to end his life, but she had also made a final phone call to Roy telling him to get back in his truck when he became scared and doubtful about killing himself by carbon monoxide poisoning. Moreover, she told Roy that his family was “prepared” for him to die and would “get over it and move on.”

At trial, the prosecution asserted that Carter was motivated by a need for public attention from her boyfriend’s death, and their supposed relationship was almost entirely “virtual” (ie, online and texting). Carter’s defense team argued, among other things, that her use of antidepressants caused an “involuntarily intoxication,” resulting in a “delusional” mental state that precluded her from forming any criminal intent.

Carter had been prescribed Prozac between 2011 and 2013, and subsequently Celexa in 2014. The defense relied on the testimony of psychiatrist Peter Breggin who has testified in a number of high-profile cases that criminal defendants would not have committed their offenses had they not been on antidepressants. In Carter’s case, Dr. Breggin testified:

[Carter] was enmeshed in a delusional system . . . enmeshed in . . . really . . . a delusion where she’s thinking that it’s a good thing to help him die. . . . [S]he was unable to form intent because she was so grandiose that what she was doing was not to harm-it was not an intent to harm-even though she was encouraging his suicide, her absolute intent was to help Conrad.

Dr. Breggin went on to testify that by examining Carter’s texts, he could pinpoint the precise day Carter became involuntarily intoxicated by her antidepressant, as well as the day it began “wearing off.” Dr. Breggin’s testimony notwithstanding, Judge Lawrence Moniz found Carter guilty of involuntary manslaughter. Interestingly, Judge Moniz noted that it was Carter’s phone calls to Roy during the time he was poisoning himself with carbon monoxide that most influenced his decision, as opposed to Carter’s persistent text messages. Carter was sentenced to 15 months plus 5 years of probation; however, she is currently free while her sentence is being appealed.

The defense strategy of shifting the focus away from a defendant’s mental state at the time of the offense and onto an antidepressant has become somewhat familiar in high-profile criminal cases. For example, in the tragic mass shooting case of James Holmes, who shot into a movie audience in Aurora, Colorado, in 2012, psychiatrist David Healy advised Holmes’s defense team. Although Dr. Healy did not testify in the case, he was interviewed by the media, stating: “I believe if [Holmes] hadn’t taken the sertraline, he wouldn’t have murdered anyone.”13

In a related narrative, the BBC program aired the show “A Prescription for Murder.”14 The show’s premise was that antidepressants may induce violent thoughts and perhaps led to Holmes’ offense by reducing his levels of “fear and distress.” Of course, the program entirely neglected “to consider the published scientific evidence about how antidepressants work; the meta-analyses and systematic reviews about antidepressants and their side effects; and the role of randomized controlled trials in excluding confirmation bias and other confounding factors.”15


Defense attorneys must always be zealous advocates for their clients, and so it is not surprising when they grasp at any possible straw for a defense strategy. But psychiatric experts who testify in court are not zealous advocates. Nor are they on a mission to promote their own agenda. Rather, they are there to educate the court on matters of psychiatric clinical science that are reliable and can pass the relevant admissibility tests.

Equally as important, they must readily acknowledge current limitations in psychiatric science, of which there are many. Testifying with unwarranted certainty about high-controversy topics in the field will virtually never be helpful to courts. Yet the consequences, in terms of perpetuating stigma and confusion, are likely to go far beyond the courtroom. Testimony by experts in high-profile cases may be taken up and transmitted by the media, who not uncommonly put forth a contentious narrative in a manner that shocks or frightens. Furthermore, testimony under oath and the mantle of expertise lends pseudo-credibility to misguided notions and fear about psychiatric treatment already present in society.


Acknowledgment-We are grateful to Ronald Pies, MD, and Thomas Schwartz, MD, for reviewing the manuscript and for their feedback and editorial comments.



Dr. Knoll is Professor of Psychiatry at the SUNY Upstate Medical Center in Syracuse, NY; he is Editor-in-Chief Emeritus of Psychiatric Times. Dr. Annas is Assistant Professor of Psychiatry and Behavioral Sciences at SUNY Upstate Medical Center.


1. Knoll Jl. Warning: antidepressants may cause bank robbery. Psychiatric Times. November 2013. Accessed August 17, 2017.

2. Pratt LA, Brody DJ, Gu Q. Antidepressant use among persons aged 12 and over: United States, 2011-2014. NCHS Data Brief, No 283. Hyattsville, MD: National Center for Health Statistics; 2017.

3. National Center for Health Statistics. Health, United States, 2015: With special feature on racial and ethnic health disparities. Table 80: Selected prescription drug classes used in the past 30 days, by sex and age: United States, selected years 1988-1994 through 2009-2012. Hyattsville, MD. 2016.

4. Bouvy PF, Liem M. Antidepressants and lethal violence in the Netherlands 1994-2008. Psychopharmacol (Berl). 2012;222:499-506.

5. Walsh M, Dinan T. Selective serotonin reuptake inhibitors and violence: a review of the available evidence. Acta Psychiatr Scand. 2001;104:84-91.

6. George DT, Phillips MJ, Lishitz M, et al. Fluoxetine treatment of alcoholic perpetrators of domestic violence: a 12-week, double-blind, randomized, placebo-controlled intervention study. J Clin Psychiatry. 2011;72:60-65.

7. Hedlund J, Forsman J, Sturup J, Masterman T. Psychotropic medications in Swedish homicide victims and offenders: a forensic-toxicological case-control study of adherence and recreational use. J Clin Psychiatry. 2017;pii:16m11244.

8. Chang Z, Lichtenstein P, Langstrom N, et al. Association between prescription of major psychotropic medications and violent reoffending after prison release. JAMA. 2016;316:1798-1807.

9. Crockett MJ, Clark L, Hauser MD, Robbins TW. Serotonin selectively influences moral judgment and behavior through effects on harm aversion. Proc Natl Acad Sci USA. 2010;107:17433-17438.

10. Siegel JZ, Crockett MJ. How serotonin shapes moral judgment and behavior. Ann NY Acad Sci. 2013;1299:42-51.

11. Molero Y, Lichtenstein P, Zetterqvist J, et al. Selective serotonin reuptake inhibitors and violent crime: a cohort study. PLoS Med. 2015;12:e1001875.

12. Pozzi M, Radice S, Clementi E, et al. Antidepressants and, suicide and self-injury: causal or casual association? Int J Psychiatry Clin Pract. 2016;20:47-51.

13. Knapton S. Antidepressants linked to murders and murderous thoughts. The Telegraph. July 26, 2017. http://www.telegraph.co.uk/science/2017/07/25/antidepressants-linked-murders-murderous-thoughts/. Accessed August 18, 2017.

14. BBC. The Batman Killer: A Prescription for Murder. http://www.bbc.co.uk/news/resources/idt-sh/aurora_shooting. Accessed August 17, 2017.

15. Adshead G. Antidepressants and murder: case not closed. BMJ. 2017;358:j3697.

Additional reading

• Piquero AR. Taking stock of developmental trajectories of criminal activity over the life course. In: Liberman A, ed. The Long View of Crime: A Synthesis of Longitudinal Research. New York, NY: Springer; 2008:23-78.

• Sweeten G, Piquero AR, Steinberg L. Age and the explanation of crime, revisited. J Youth Adolesc. 2013;42:921-938.

• Wilson M, Daly M. Competitiveness, risk taking, and violence: the young male syndrome. Ethol Sociobiol. 1985;6:59-73.