Comparing the Brains of ADHDers and Criminals

A quarter of the prison population has ADHD, and ADHD has been linked to re-offending. What is it that makes ADHD so common in criminals? Are there similarities between ADHDers and criminals? Structurally, speaking there is.



The amygdala regulates emotion and is key in the generation of emotions such as anger, rage, and fear. It is also believed to be considerably influential in aggression and other antisocial behavior (Beaver 2009). Moreover, the amygdala has an involvement in emotional learning and fear conditioning, the instinctual reaction of fear when a person encounters a stimulus that had previously produced fear. Poor fear conditioning can be a sign of problems with one’s amygdala.

Hoogman et al (2017) found that ADHDers have smaller amygdalae than non-ADHDers. The amygdalae of psychopaths are 18% smaller than is to be expected (Raine 2013). Furthermore, in 1994, Adrien Raine, Monte Buchsbaum, and Lori LaCasse found that murderers have poor functioning in their amygdalae (Raine 2013)The similarity between the brains of ADHDers and psychopaths is concerning because many known psychopaths are violent criminals.



The hippocampus is involved in learning and emotions. Like the amygdala, it assists in emotional learning and fear conditioning (Beaver 2009). Moreover, it helps with the processing of socially relevant information (Raine 2013). When the hippocampus is not functioning as it should, inappropriate and sometimes illegal behaviors can emerge, behaviors that are common among violent individuals.

Hoogman et al (2017) also found the hippocampi of ADHD brains to be smaller than average. Similar findings have shown up in the brains of those with violent tendencies. A study conducted in London showed that boys exhibiting antisocial and conduct-disorder behaviors had reduced functioning in their hippocampi (Raine 2013). Swedish scientist Henrik Soderstrom performed functional brain scans on individuals who were likely psychopaths and found reduced hippocampal functioning. Raine, Buchsbaum, and LaCasse also found, in 1994, that murderers have poor functioning in their hippocampi (Raine 2013) According to Raine (2013), murderers have reduced hippocampal volume.

The Frontal Lobe


The frontal lobe is another area of concern for ADHDers and criminologists. It is in charge of executive functioning, controlling emotional responses produced by the limbic system (of which the amygdala and hippocampus are a part), problem solving, and judgment. In other words, it prevents us from doing stupid stuff.

A 2017 study of young adults with ADHD (Gehricke et al) found abnormalities in the frontal lobe of the ADHD brains scanned. Jacobson et al (2018) found that the frontal lobes of four and five year olds with ADHD were smaller than were to be expected. In a criminology study, spouse abusers were found to have more active limbic systems and less active prefrontal cortices (Beaver 2009). This means the prefrontal cortex (located in the frontal lobe) was unable to control the emotions created by the limbic system, resulting in crime. In the aforementioned 1994 study by Raine, Buchsbaum, and LaCasse, they found reduced prefrontal cortex functioning in murderers.

Gray Matter


Gray matter is responsible for the processing of information. (It is a lot more complicated than that one sentence says, but for our purposes, this is what you need to know.)

It has been noted that ADHD brains have reduced densities of gray matter (Ellison-Wright et al (2008), Nakao et al (2011), and Proal et al (2011)). On the criminal side of things, one study found that those who had been diagnosed with antisocial personality disorder had an 11% reduction of gray matter in the prefrontal cortex as compared to controls (Raine 2013). This reduces their cognitive functioning in the prefrontal cortex, making it difficult for them to process information and control their emotions. Multiple sources have reported significant reductions in gray matter in the prefrontal cortices of psychopaths (Beaver 2009).



The caudate nucleus and the putamen have also been found to be smaller in ADHD brains (Hoogman et al 2017). These are components of the striatum, a section of the brain that has been associated with impulsive and reward-seeking behavior (Raine 2013). The reduced size of these brain parts is significant because the striatum in psychopaths and those with antisocial personality disorder has been found to be larger than normal (Raine 2013). Here is an area where ADHDers and those who have a strong propensity for criminal behavior do not have a similarity.

Are ADHDers Doomed to a Life of Crime?

NO! Just because someone has a predisposition to violence doesn’t mean they will inevitably commit a crime. I present this information so that the importance of addressing ADHD can be known. The sooner we can intervene in the lives of those with ADHD, the sooner they can learn to manage their brain and use it for good, not evil. Yes, many people with ADHD have committed crimes, but there are many successful ADHDers who have made valuable contributions to society. It may take some effort (and perhaps a little coaching), but ADHDers can live a beautiful life.

Today’s Reset ADHD Challenge:

Take control of your ADHD before it takes control of you!


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  • Ellison-Wright I, Ellison-Wright Z, Bullmore E. Structural brain change in attention deficit hyperactivity disorder identified by meta-analysis. BMC Psychiatry 2008; 8: 51.

  • Gehricke JG, Kruggel F, Thampipop T, Alejo SD, Tatos E, et al. (2017) The brain anatomy of attention-deficit/hyperactivity disorder in young adults – a magnetic resonance imaging study. PLOS ONE 12(4): e0175433.

  • Hoogman, M. et al. Subcortical brain volume differences in participants with attention deficit hyperactivity disorder in children and adults: a cross-sectional mega-analysis. The Lancet Psychiatry, 2017; DOI: 10.1016/S2215-0366(17)30049-4

  • Jacobson, L., Crocetti, D., Dirlikov, B., Slifer, K., Denckla, M., Mostofsky, S., & Mahone, E. (2018). Anomalous Brain Development Is Evident in Preschoolers With Attention-Deficit/Hyperactivity Disorder. Journal of the International Neuropsychological Society, 24(6), 531-539. doi:10.1017/S1355617718000103

  • Nakao T, Radua J, Rubia K, et al. Gray matter volume abnormalities in ADHD: voxel-based meta-analysis exploring the effects of age and stimulant medication. Am J Psychiatry 2011; 168: 1154-1163.

  • Proal E, Reiss PT, Klein RG, et al. Brain gray matter deficits at 33-year follow-up in adults with attention-deficit/hyperactivity disorder established in childhood. Arch Gen Psychiatry 2011; 68: 1122-1134.

  • Raine, A. (2013). The Anatomy of Violence: The Biological Roots of Crime.  New York, NY: Pantheon Books. ISBN: 978-0307378842.