Mothers who are depressed or severely stressed during their pregnancy face a far greater chance of having children with attention deficit hyperactivity disorder, new research has found.

Although ADHD is largely inheritable, scientists say antenatal anxiety could contribute to 15 per cent of cases of the behavioural condition.

The British study of thousands of children from before birth until they were at primary school discovered a strong link between antenatal stress, “mixed-handedness” — using the left or right hand to perform different tasks — and severe childhood behavioural problems, with ADHD the most common.

The neurologists who conducted the research said their findings suggested stress hormones in the womb disrupted the normal passage of neurons between the two hemispheres of the brain, resulting in the inability of one hand to become dominant, and a range of behavioural problems.

Although previous studies have discovered a link between stress and low birthweight and lower IQ, this is the first time a connection has been made between antenatal stress and ADHD. The research was presented at the annual meeting of the British Psychological Society by Alina Rodriguez from the Institute of Psychiatry at King’s College London.

ADHD is one of the most common behavioural disorders of childhood. Children with ADHD often appear reckless and impulsive and have trouble paying attention. It can be treated with talking therapies and, in more extreme cases, with medication such as Ritalin.

However, the prevalence of ADHD is fiercely contested. There is no diagnostic test and some doctors and teachers claim that ADHD is simply an excuse for bad behaviour. They believe that far too many children are on medication when better discipline is required.

Dr Rodriguez said the research showed clearly that mixed-handedness could be an early sign of ADHD symptoms.

Her previous research has shown that mixed-handed children are twice as likely as right-handed children to have ADHD symptoms, but the connection with stress in pregnancy, which leads to twice as many mixed-handed children, is a new discovery. Dr Rodriguez said she hoped this new research would shift the debate towards prevention and lead to more work on supporting pregnant women.

Source: The Australian –