Neonatal jaundice and increased risk of ADHD

The findings from Chang-Ching Wei and colleagues [1] suggesting an over-representation of the diagnosis of attention-deficit hyperactivity disorder (ADHD) following a history of neonatal jaundice provides fodder for today's brief post. Based in Taiwan, one of the most impressive countries when it comes to the use and analysis of 'big data' (see here), researchers were able to identify some 25,000 participants diagnosed with neonatal jaundice and compare them with almost 70,000 non-jaundiced controls to calculate: "the incidence rate and hazard ratios (HRs) of physician-diagnosed ADHD".

"Imperial troops have entered the base"

They observed that the "incidence of ADHD was 2.48-fold greater in the jaundice cohort than in the nonjaundice cohort (3.84 vs. 1.51 per 100,000 person-years) in the study period" between 2000 and 2008. Several other variables also seemed to affect the HR of ADHD including being male, being born preterm and being a low birth weight infant. To my mind, finding such variables already potentially connected to a heightened risk for a diagnosis of ADHD [2] strengthens the Wei results when it comes to jaundice potentially also being a risk factor. The authors conclude: "A risk alert regarding neurologic consequences is urgently required after a neonatal jaundice diagnosis" bearing in mind the need for further research on the potential mechanisms at work in this proposed relationship.

I'm becoming pretty interested in the cognitive and developmental outcomes associated with cases of neonatal jaundice. As per previous posts on this blog on jaundice and autism (see here and more recently here), there are definitely grounds for quite a bit more investigation in this area. The overlap between something like ADHD with autism (at least some of the autisms) also begs the question whether there may be some tie up between the various diagnoses and something like neonatal jaundice. It certainly wouldn't be the first time that ADHD and autism have been mentioned with the same risk factors in mind as for example, with the increasingly interesting area of asthma and childhood neurodevelopmental issues (see here and see here)...

Music to finish. I assume most people have heard the very sad news about actor and comedian Robin Williams this morning. Just the other day I was introducing my brood to Mork and Mindy... RIP.

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[1] Wei CC. et al. Neonatal jaundice and increased risk of attention-deficit hyperactivity disorder: a population-based cohort study. J Child Psychol Psychiatry. 2014 Jul 24.

[2] Chu SM. et al. The relationship between attention deficit hyperactivity disorder and premature infants in Taiwanese: a case control study. BMC Psychiatry. 2012 Jul 23;12:85.

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Wei CC, Chang CH, Lin CL, Chang SN, Li TC, & Kao CH (2014). Neonatal jaundice and increased risk of attention-deficit hyperactivity disorder: a population-based cohort study. Journal of child psychology and psychiatry, and allied disciplines PMID: 25056274