Psychopathic Behaviour Linked to Brain Chemical Imbalance

[New evidence for an association between the CSF HVA: 5-HIAA ratio and psychopathic traits 2003; 74:918-21]

Psychopathic behaviour seems to be linked to an imbalance in critical brain chemicals, reveals a study of violent and sexual offenders, reported in the Journal of Neurology Neurosurgery and Psychiatry.

The findings are based on 28 men up to the age of 45, all of whom had committed violent crimes, including murder, attempted murder, aggravated assault, arson, rape, or sexual assault of children.

The psychopathic personality trait is characterised by inconsistent, impulsive behaviour and a tendency to dominate others, using violence and aggression.

Samples of the fluid bathing the brain and the spine (cerebrospinal fluid) were taken from each of the men to test for levels of 5-hydroxyindoleacetic acid (5-HIAA) and homovanillic acid (HVA). 5-HIAA is a metabolite of serotonin and HVA is a metabolite of dopamine. Serotonin regulates dopamine, levels of which influence aggressive impulses.

The men were scored against a checklist for the psychopathic personality trait and carefully assessed for evidence of disruptive childhood behaviours, such as attention deficit hyperactivity disorder (ADHD) and conduct disorder.

The results showed that higher levels of HVA and lower levels of 5-HIAA were significantly associated with all psychopathic traits, but especially the behavioural aspects, in this group of men. The ratio of these two metabolites was the critical factor. The results confirm those of a previous recent study of 22 violent men, carried out by the same authors, lending more weight to the results, they say.

The HVA:5-HIAA ratio was also strongly linked to a history of childhood disruptive behaviours, and the authors suggest that a combination of ADHD and conduct disorder, might be a precursor to adult psychopathic behaviour.

Click here to view the full paper:http://press.psprings.co.uk/jnnp/july/jn02590.pdf