Two Irish genetic teams are making significant contributions to the international quest to find genes linked to Attention Deficit Hyperactivity Disorder (ADHD).
ADHD is a neurobiological disability which is frequently characterised by inappropriate degrees of inattention, impulsivity and hyperactivity, and is estimated to affect 5-10 per cent of Irish children.
If left untreated, a child is at significant risk of developing impaired learning ability, decreased self-esteem, social problems, family difficulties and potential serious long-term problems.
Irish research has confirmed that a child's susceptibility to ADHD depends on many genes as well as environmental factors.
It is known that dopamine, a neuro-transmitter used for signalling by nerve cells in the brain, is linked to ADHD.
Trinity College Dublin neuropsychiatric geneticist Dr Ziarih Hawi and colleagues have now confirmed that the dopamine transporter gene is associated with susceptibility to ADHD.
Crucially, this may determine how well a child responds to medication, according to the team.
Another risk gene, coding for one of the dopamine receptors, has also been identified by the team.
Also in TCD, psychiatrists Prof Michael Gill and Dr Mark Bellgrove have found that people's ability to sustain their attention during repetitive tasks is affected by several genes that code for neurotransmitters.
This suggests that the genes implicated in ADHD may also be responsible for the cognitive problems such as difficulties in thinking and planning.
Meanwhile, a study in TCD has revealed that "time training" might improve the attention skills of children with ADHD.
There are two main types of ADHD - children whose problem is inattention and children who, in addition to inattention, suffer from hyperactivity and impulsiveness.
According to research psychologist Dr Celine Mullins, both groups seem to perceive that time runs fast so that five minutes might feel more like 10 minutes.
In a time-perception study, Dr Mullins found that ADHD children have poor time perception and that this is not just because of their attention difficulties.
She believes that time training, involving clapping and toe-tapping to a metronome, could help children with ADHD to improve their sense of time and perhaps even win some control over their attention deficits and impulsiveness.