Mental illnesses have been found in some of the U.S.’s most loathsome killers throughout history, but it’s important to note that most people suffering from these illnesses do not commit any violent offenses. These instances of mental disorders represent only a small fraction of people diagnosed and the majority of people afflicted do not engage in criminal activity, especially if given proper treatment and social support.
In the wake of a violent assault, robbery, or murder, forensic psychologists typically examine the mental correlates of criminality. In order to get to the root of a behavior, these justice system professionals will often ask such questions as:
Not surprisingly, many criminals have been diagnosed with mental illnesses and may be suffering from co-occurring substance abuse.
So what are some of the most common psychological disorders associated with history’s most infamous American criminals—serial killers and terrorists in particular?
According to WebMD, schizophrenia—a wide-ranging (and often misdiagnosed) mental illness—lists symptoms ranging from hallucination and delusions to emotional flatness and catatonia. It is one of the most common mental disorders diagnosed among criminals, especially serial killers:
This disease is characterized by impulsive behaviors, intense mood swings, feelings of low self worth, and problems in interpersonal relationships (WebMD). It has also been diagnosed among some of the U.S.’s most notorious serial killers. Interestingly, this seems more common among female criminals:
Known in the past as “psychopathy,” this mental disorder is characterized by a total disregard of the feelings of others. People with APD may lie, act out violently, or break the law and show no remorse. WebMD reports that while APD only affects 0.6% of the population, it may affect up to 47% of male inmates and 21% of female inmates. It’s also been diagnosed among three of the most ruthless American serial killers:
While these three disorders are commonly seen among violent criminals, there have also been a number of killers whom were never diagnosed with mental illnesses. For example, Dean Corll, also known as the “Candy Man” or the “Pied Piper,” kidnapped, raped, and killed 28 boys between 1970 and 1973 in Houston, Texas and was never diagnosed. Additionally, Timothy McVeigh, the Oklahoma City bomber of 1995, killed 168 people and injured over 600, and yet he too never was given a mental illness diagnosis.
Still, mental illness in prison populations and among criminals continues to be an issue in the United States today. In order to decrease prison recidivism and rates of violent crime, it’s essential that rehabilitative services and mental illness treatments be improved in this dangerous yet vulnerable population.