3-5% of children suffer from ADHD. Countries like USA report considerably high rates and this have sparked debates about the concept of the disorder, diagnostic threshold and broader themes of over medicalisation. ADHD’s association with criminal behaviour is well established. It is often associated with Conduct disorder. There is enough good quality evidence to say that medications work really well in this disorder (more so for short-term effects). Though half of the children would have persistent ADHD symptoms in adulthood, treatment is discontinued in most cases. Our knowledge of ADHD in adults is limited and services for this group is either non-existent or in its infancy in many countries.
If we treat ADHD would that have any effect on criminality?
Paul Lichtenstein and colleagues from Karolinska Institute and Oxford University used the Swedish population-based data to investigate the association between the use of ADHD medication and criminality.They identified 25,656 patients (16,087 men and 9569 women) who had been born no later than 1990 with at least one diagnosis of ADHD and this was linked to the Prescribed Drug Register.A general population sample was used as control group.Criminality was identified through the National Crime Register. Migration, Cause of Death, and Prison Registers were also used to ensure quality of data.The main outcome was any conviction for a crime.
Born in 1990 or earlier, 25,000 patients, around half in the age group 15-24 yrs, one third 25-39 yrs. 80% unmarried. Quarter are employed.
1. 37% of men and 15% of women with ADHD committed a crime as against 9% of men and 2% of women among those who do not have ADHD.
2. The stratified Cox regression hazard ratio was 0.68 (95% confidence interval ( 0.63 to 0.73) for men and 0.59 (95% CI, 0.50 to 0.70) for women, indicating that medication use was associated with a lower criminality rate). This mean that while on medications, men were 32 % less likely to be convicted of a crime and women were 41% less likely to be convicted.
3. Reductions in criminality rates is regardless of whether the drug was a stimulant or a non stimulant or whether analyses were restricted to less severe or specific crimes.
Medication might be reducing impulsive choices and may be enabling them to organise their life better.
Pharmacoepidemiologic studies are open to confounding (for eg:patients who are receiving treatment are different from those who are not receiving treatment, usually because they are more symptomatic and have co-existing disorders). Though most of such factors have been accounted for in the analysis, unknown factors still could be operating.
Conclusions: A good proportion of convicted people have ADHD. Medications substantially reduce criminal behaviour. Assessment opportunities and provision for treatments in this group needs to be reviewed as individual and societal benefits are likely to be substantial.
Summary of the article: Medication for attention deficit-hyperactivity disorder and criminality. Lichtenstein P, Halldner L, Zetterqvist J, Sjölander A, Serlachius E, Fazel S, Långström N, Larsson H. N Engl J Med. 2012 Nov 22;367(21):2006-14.