Mental Illness and Capital Punishment: Potential Complications

June 22, 2017

The authors discuss some potential complications arising from a constitutional ban on executing persons with mental illness.



The US Supreme Court has been slowly but steadily “chipping away” at the death penalty. Lee and Hall’s well-written article gives a prescient window of insight into the process. After the more easily confirmed disqualifiers of age and intellectual disorder have been decided, is not serious mental illness now a predictable consideration? If so, how will a dividing line be drawn between serious mental illness and “any” type of mental illness? In both Roper and Atkins, the Supreme Court also considered the risk of false convictions and unfair sentences.1

These concerns flowed from the notion that juveniles and persons with intellectual disabilities may be inordinately impressionable, and thus unduly prone to outside influence in committing the crime, as well as at risk for false confessions. Can these same concerns now be applied to persons with mental illness? The likelihood does seem strong for a future prohibition of the death penalty for persons with mental illness.

What is of interest now are the long-term ramifications and challenges that may be forthcoming. In this article, we discuss some potential complications arising from a constitutional ban on executing persons with mental illness.

CTBE evaluations

To be sure, complications are encountered in other areas of forensic psychiatric criminal evaluations. For example, competence to be executed (CTBE) evaluations (evaluations for death penalty eligibility) take the evaluator much closer to the moral and ethical fire of an execution than other types of evaluations. The American Medical Association’s Council on Ethical and Judicial Affairs concluded that conducting CTBE evaluations is permissible because the forensic psychiatrist is acting as an advocate of the justice system-not as part of the process of punishment.2 There are 2 critical factors to keep in mind:

1. There is no doctor-patient relationship between the forensic psychiatrist and inmate

2. The evaluating forensic psychiatrist is not “directly participating” in an execution

Regarding the second point, the American Medical Association has taken the unequivocal position that it is unethical for any physician to directly participate in an execution.

A constitutional ban on executing persons with mental illness would introduce a new type of forensic psychiatric evaluation (at least in terms of when it is conducted) that would require review by professional organizations such as the American Medical Association, the American Psychiatric Association, and the American Academy of Psychiatry and the Law. Yet there remain diverse opinions about the ethical permissibility of psychiatrists’ participation in death penalty cases.

CTBE evaluations present complex ethical issues with little consensus guidance. A research survey of 290 forensic psychiatrists found that many did not share the views of their professional organizations. Only 8.5% believed that it was never acceptable to evaluate a condemned prisoner, and about half believed that an inmate who is incompetent to be executed should be treated to restore competence.3

Regardless of fluctuating support over time for the death penalty, one feature remains constant-the decision to sentence someone to death is a “moral judgment” that is inextricably associated with emotions.

Another important issue in any death penalty-related forensic evaluation is how well the forensic evaluator can maintain objectivity. It has been observed that the moral burden in such evaluations is likely to “fall most heavily on those who hold the greatest moral doubts about the death penalty.”4 Unsurprisingly, research has supported the common-sense notion that advocacy-focused results may occur in capital cases.

A study of 206 forensic psychologists found that evaluator attitudes toward capital punishment influenced their willingness to accept capital case referrals from either the defense or the prosecution (ie, stronger death penalty opposition was associated with higher willingness to work for the defense).5 The authors concluded that the findings suggest a “skewed” involvement of evaluators and a possible “allegiance effect” in capital cases. This research seems to support previous findings that a moral opposition to the death penalty is associated with a reluctance to participate in evaluations of CTBE.6

“Death eligibility” evaluations

Assuming that the objectivity of evaluators can be relied on and that their respective professional organizations support evaluations for death penalty eligibility-the next challenges will be related to the complexities of such high-stakes forensic evaluations. In terms of practicality, one must factor in the time burden necessary to carry out such detailed evaluations, and whether this would negatively impact the already “inordinate” period that inmates spend on death row (assuming the evaluation is done after sentencing on appeal). As Lee and Hall note, the 2014 case of Jones v Chappell found that systemic delay in California’s death penalty system renders it unconstitutional. In California, the time between sentence and execution is 25 years, which is about twice the national average.

“Death eligibility” forensic evaluations will demand that the evaluator, as in all criminal forensic evaluations, consider the possibility of malingering. In high-stakes criminal forensic evaluations, this amounts to a very thorough, multimodal approach that involves interview techniques, collection of collateral data, and psychological testing designed to detect malingered mental illness. While there is much research on the detection of malingered mental illness, it remains a contentious area subject to bias and uncertainty.

Lee and Hall point out that depression and PTSD may be considered as mental illnesses for the purpose of death penalty ineligibility. In contrast to psychotic disorders, less is known about the validity of methods used to detect malingering of more subtle disorders such as depression. This may present problems in that both diagnoses rely heavily on the individual’s self-report and thus both may be easily malingered. PTSD in particular has been noted to pose a “formidable challenge because of the apparent ease” with which it may be malingered.7-9 One might well imagine that with the death penalty at stake, evaluations focusing on possible malingered depression and PTSD will be subjected to a new level of scrutiny.

Continuing the theme of diagnostic uncertainty, the US Supreme Court case of Clark v Arizona (2006) provides a clarion call to improve psychiatric diagnosis.10 In Clark, the Court reaffirmed the rights of individual states to have their own “formulation of legal insanity” and went on to provide some important insights into its attitudes on the insanity defense in general. The Court remarked on “the controversial character of some categories of mental disease,” as well as “the potential of mental-disease evidence to mislead.”10 The Court noted that a “diagnosis may mask vigorous debate within the profession about the very contours of the mental disease itself.”10

“Death eligibility” forensic evaluations will demand that the evaluator, as in all criminal forensic evaluations, consider the possibility of malingering.

Now consider the example of one of the most common psychiatric disorders, MDD. The DSM-5 field trials revealed “discouragingly low” interrater reliability. Yet we know that the phenomenon of depression is heterogeneous, multidetermined (when not due to a single medical condition), and individual specific. To further complicate matters, it has been observed that “DSM-5 does little to improve its predecessors’ standing in the legal forum or the court of public perception and creates robust opportunities for challenges by attorneys opposing diagnostic testimony.”11 Given the uncertain contours of mental disease, particularly those other than the chronic psychoses and bipolar disorder, would the courts have to contend with “diagnostic creep” in death penalty eligibility psychiatric evaluations?

Pushing this line of thought out to its limits, some contend that “neuroscience will demonstrate that many more offenders should be excused and do not deserve the harsh punishments imposed by the United States criminal justice system.”12 The problematic endgame is that this theory eventually collapses “into the nihilistic conclusion that no one is really criminally responsible.” Returning to Clark, the Supreme Court noted that “there is the potential of mental-disease evidence to mislead,” and “to suggest that a defendant suffering from a recognized mental disease lacks cognitive, moral, volitional, or other capacity, when that may not be a sound conclusion at all.”10

Should the legal test for death penalty ineligibility too closely resemble insanity criteria, including cognitive (wrongfulness) and even volitional (inability to control behavior) tests, this will surely result in rather complicated evaluations, testimony, and cross-examination. This type of ex post guilt/innocence phase insanity test seems likely to raise many nuanced complexities and challenges.

With the 2 classes of persons exempted by Roper and Atkins (juveniles and persons with intellectual disabilities), juries can be presented with relatively clear, tangible data: ie, with juveniles, age is objectively verifiable; with intellectual disability, there must be onset before age 18. Yet with many types of mental illness, the proof is often less distinct. Furthermore, juries are frequently skeptical of the insanity defense. When they do render a verdict of insanity, it is when the defendant suffered from a serious psychotic disorder and had prior hospitalizations for the disorder.

Finally, defense attorneys will need to carefully consider the idea that juries can sometimes treat mental illness as an aggravating factor with regard to sentencing. This may lead some attorneys to advise their clients against using mental illness as an ineligibility factor until such time that public perceptions about mental illness change.

At present, capital punishment is legal in a majority (32) of US states. While the annual number of US executions peaked in 1999 (98 executions), the number of annual executions has fallen steadily since then. For example, in 2016, 20 inmates were executed. Thus, the 1990s can be considered a high-water mark for support of the death penalty, as well as for imposing it. Note that this period followed a 4-year moratorium as well as the law-and-order period of the 1980s. Stepping back and attempting to take stock, there appears to be a recurring sine wave of support for the death penalty over time. In the mid-1960s, public support descended to about 47%, then rose again to about 80% in the mid-1990s.13 In 2016, support went back down to 49%.

Related content:

The Death Penalty and Mental Illness: An Evolving Standard?

This type of pattern might reasonably cause one to wonder whether the US is headed for another moratorium or some type of substantial change in how the death penalty is carried out. The recent rush in Arkansas to execute 4 death row inmates because of the expiration date of the midazolam used in their lethal injection protocol reveals another area of active chipping away. Consider not only the practical, but legal outcome should drug manufacturers continue the trend of adopting policies that prohibit their products from being used in executions. This is already partly the case with companies such as Pfizer, as well as relevant professional organizations such as the American Pharmacists Association. Should states run out of drugs to use for lethal injections, other forms of execution are unlikely to be viewed favorably by the courts, per the evolving standards of decency reasoning, and will encounter Eighth Amendment challenges.

Regardless of fluctuating support over time for the death penalty, one feature remains constant-the decision to sentence someone to death is a “moral judgment” that is inextricably associated with emotions. This fact will always thwart attempts to transform the issue into a sterile analysis. How else to explain the persistence and non-resolution of the argument, other than the strong emotional variables that ultimately undergird all so-called rational debate?


Dr. Knoll is Professor of Psychiatry at the SUNY Upstate Medical Center in Syracuse, Director of Forensic Psychiatry, and Director of the Forensic Psychiatry Fellowship at Central New York Psychiatric Center. Professor Chhablani is Professor of Law, Syracuse University College of Law, Syracuse, NY.

The authors report no conflicts of interest concerning the subject matter of this article.


1. Sundby S. The true legacy of Atkins and Roper: the unreliability principle, mentally ill defendants, and the death penalty’s unraveling. Wm Mary Bill Rts J. 2014;23:487.

2. Council on Ethical and Judicial Affairs, American Medical Association. Physician participation on capital punishment: evaluation of prisoner competence to be executed; treatment to restore competence to be executed. House of Delegates Proceedings of 144th Annual Meeting. CEJA Report 6-A-95; 1995.

3. Leong G, Silva J, Weinstock R, Ganzini L. Survey of forensic psychiatrists on evaluation and treatment of prisoners on death row. J Am Acad Psych Law. 2000;28:427-432.

4. Bonnie R. Dilemmas in administering the death penalty: Conscientious abstention, professional ethics and the needs of the legal system. Law Hum Behav. 1990;14:67-90.

5. Neal TMS. Are forensic experts already biased before adversarial legal parties hire them? PLoS One. 2016;11:e0154434.

6. Deitchman M, Kennedy W, Beckham J. Self-selection factors in the participation of mental health professionals in competency for execution evaluations. Law Hum Behav. 1991;15:287-299.

7. Wooley CN, Rogers R. The effectiveness of the Personality Assessment Inventory with feigned PTSD: an initial investigation of Resnick’s model of malingering. Assessment. 2015;22:449-458.

8. Resnick PJ, West S, Payne JW. Malingering of posttraumatic disorders. In: Rogers R, ed. Clinical Assessment of Malingering and Deception. New York: Guilford Press; 1997:130-152.

9. Kunst MJ, Winkel FW. PTSD symptom reporting and persistent malingering in recipients of state compensation for violent crime victimization: an exploratory study. J Foren Psychiatry Psychol. 2015;26:309-324.

10.Clark v Arizona, 548 US 735 (2006).

11. Hagan LD, Guilmette TJ. DSM-5: challenging diagnostic testimony. Int J Law Psychiatry. 2015;42:128-134.

12. Morse S. Avoiding Irrational NeuroLaw Exuberance: A Plea for Neuromodesty. 2011. Accessed May 5, 2017.

13. Oliphant B. Support for Death Penalty Lowest in More Than Four Decades. Pew Research Center; September 29, 2016. Accessed May 5, 2017.