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Facts Sheet: Mental Illness

last updated July 25, 2004

A high percentage of death row inmates are severely mentally ill.

  • As many as 370—or more than one in ten—people currently on death row suffer from severe mental illnesses.
  • A 1986 study of fifteen death row inmates showed:
    • all inmates had suffered severe head injuries in childhood,
    • half of the inmates had been severely injured by assaults, and
    • six inmates were chronically psychotic.
  • A 2000 study of sixteen death row inmates in California found that all had evidence of mental illness. Of the sixteen:
    • fourteen inmates had post-traumatic stress disorder,
    • fourteen inmates had endured extreme physical and/or sexual abuse, 
    • thirteen inmates had severe depression, and
    • twelve inmates had evidence of traumatic brain injury.

Juveniles on death row are particularly likely to suffer mental disorders.

  • A 1980 study  conducted by Dorothy O. Lewis indicates that half of all juveniles sentenced to death have some form of psychosis.
  • A study of fourteen juvenile death row inmates found that:
    • all had suffered head injuries,
    • twelve had suffered extreme physical abuse, and
    • five had been sodomized by relatives.

Many mentally ill offenders do not know they require treatment. 

  • Research indicates that approximately half of all individuals diagnosed with schizophrenia do not realize they are ill.
  • According to the American Psychiatric Association, many individuals experiencing psychotic episodes are able to perform acts requiring substantial intellectual effort; however, they often do not recognize the unusual or bizarre nature of their behavior.
  • In a study of fifteen mentally ill death row inmates:
    • all but one minimized or denied their psychotic disorders
    • most could not recall how they received severe injuries and scars
    • medical records and interviews with inmates’ family members revealed that the inmates’ injuries and scars were often the results of abuse.

The law does not protect the mentally ill from unjust execution.

  • According to the National Mental Health Association, the mentally ill can be overly eager to please others and disconnected from reality, leading them to confess to crimes without fully understanding what they are being asked to do.
  • In Ford v. Wainwright, the U.S. Supreme Court held that executing the insane is unconstitutional. However, the American Psychiatric Association notes that mental illness is distinct from the legal concept of insanity—which includes only those individuals who do not understand the reason for or reality of their punishment—leaving many seriously mentally ill individuals vulnerable to capital punishment.
  • Some states are now providing treatment to the few capital offenders who do meet the narrow legal definition of insanity, hoping to render them competent to be executed.
  • Though juries are required to consider mitigating factors such as mental illness when deciding whether to impose the death penalty, many inexperienced and overworked capital defenders do not present any evidence of their clients’ mental illnesses. Case examples where jury members voted for death, but would have voted for life in prison had they known the defendant was mentally ill, include:

Many states incarcerate and execute the mentally ill instead of providing adequate mental health care services.

  • In 1999, the United States Department of Justice determined there are some 283,000 individuals suffering from severe mental illnesses in federal and state jails and prisons. Only 60% of these individuals reported they received treatment after incarceration. 
  • Public psychiatric hospitals care for only 70,000 persons with severe mental illnesses.
  • Texas, which commonly executes individuals with mental health issues, is ranked 46th in the nation for mental health care spending.


Compiled from:

American Psychiatric Association.

Capital Cases: Egregious Instances of a Horrendous Practice, at National Catholic Partnership on Disability.

The Jailed and Imprisoned Mentally Ill, available at

David Freedman and David Hemenway, Precursors of Lethal Violence: A Death Row Sample, Social Science and Medicine, Vol. 50, issue 12, June, 2002, available at

Laura Mansnerus, Damaged Brains and the Death Penalty, N.Y. Times, June 21, 2001, available at Death Penalty Information Center.

Lauri M. Flynn, No Death Penalty for Persons with Severe Mental Illnesses, at National Alliance for the Mentally Ill.

Michael King, Execution vs. Treating Ills, at Christian Science Monitor; National Mental Health Association.