20 April 2011

Premature birth tied to risk of ADHD

The earlier babies are born, the more likely they are to later get a prescription for ADHD medication, according to a new study from Sweden.


The earlier babies are born, the more likely they are to later get a prescription for ADHD medication, according to a new study from Sweden.

Researchers found that babies born as little as three weeks before their due dates had an elevated risk for attention deficit hyperactivity disorder (ADHD).

The findings suggest that mothers considering scheduling caesarean births a few weeks early reconsider and deliver as close to term as possible, the authors say.

The study

People with ADHD have trouble paying attention or controlling impulsive behaviours, and can be treated with behavioural therapy or medication.

In the new study, the researchers analysed a Swedish database of more than a million children aged six to 19 years; 7,506 of them had received a prescription for ADHD medication.

The children born extremely prematurely - between 23 and 28 weeks of pregnancy - were most at risk of later developing ADHD, with their chances being two and a half times greater than a baby born at full term (after 39 weeks).

The findings

Fifteen out of every 1,000 babies born at this extremely premature age later received a prescription for ADHD medication, compared to six out of every 1,000 babies born between 39 and 41 weeks of pregnancy.

Low birth-weight and severe prematurity were already known to be risk factors for developing ADHD.

This study confirms those findings and reveals that even babies born very close to full term - between 37 and 38 weeks of pregnancy - are still 20% more likely to develop ADHD, said Dr Anders Hjern, the lead author.

Seven out of every 1,000 children born moderately premature (37-38 weeks) were prescribed ADHD drugs.

"The finding that early term birth carries an increased risk for ADHD has important implications for planned caesarean births, which are often performed during these very weeks," Hjern said.

Minimise the risk

"To minimise the risk for ADHD these births should be planned as close to the full term date (that is week 40) as possible."

Other factors, such as the mother's smoking habits and genetics, also play a role in a child's risk of developing ADHD.

The researchers accounted for these potential influences by comparing siblings, and found that extremely premature babies remained twice as likely to develop ADHD as their full-term brothers or sisters.

The study, published in the journal Paediatrics, did not look at children diagnosed with ADHD, only those who filled a drug prescription for it.

The new research is helpful in confirming the link between prematurity and ADHD, but the underlying physiology that's actually causing the ADHD in children born prematurely is not yet understood, said Dr Glen Aylward, a professor at Southern Illinois University School of Medicine who was not involved in the current study.

The study's authors speculate that some aspect of gradual brain development could be disrupted when a baby is born early, leading later on to ADHD.

Dr Steve Faraone, a professor at SUNY Upstate Medical University, said that doctors have dramatically improved their ability to help babies survive at shorter and shorter lengths of pregnancy, "which could mean that this particular risk factor is increasing over time."(Reuters Health/ April 2011)

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ADHD Expert

Dr Renata Schoeman has been in full-time private practice as a general psychiatrist (child, adolescent and adult psychiatry) since 2008, currently based in Oude Westhof (Bellville). Renata also holds appointments as senior lecturer in Leadership (USB) and as a virtual faculty member of USB Executive Development’s Neuroleadership programme. She serves on the advisory boards of various pharmaceutical companies, as a director of the Psychiatric Management Group (PsychMG) and is the co-convenor of the South African Society of Psychiatrist (SASOP) special interest group for adult ADHD, and co-founder of the Goldilocks and The Bear Foundation ( She is passionate about corporate mental health awareness and uses her neuroscience background to assist leaders in equipping them to become balanced, healthy and dynamic leaders that take their own and their team’s emotional, intellectual, social health and physical needs into account. Renata is academically active and enjoys research and collaborative work, has published in many peer-reviewed journals, and has presented at local and international congresses. She is regularly invited to present at conferences and to engage with the media. During her post-graduate studies, she trained at Harvard, Boston in neurocognition and neuroimaging. Her awards include, amongst others, the Young Minds in Psychiatry award from the American Psychiatric Association, the Discovery Foundation Fellowship award, a Thuthuka award from the NRF, and a MRC Fellowship. She also received the Top MBA student award and the Director’s award from USB for 2015. She was a finalist for the Businesswomen’s Association of South Africa’s Businesswoman of the Year Award for 2016, and received the Excellence in Media Work award from SASOP during 2016.

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