Attention Deficit Hyperactivity Disorder (ADHD) is one of the most common neurobehavioral, chronic disorders that affects children, but can also last into adulthood. Aggression, hyperactivity, impulsivity, lack of restraint, absent-mindedness, shorter attention span, anxiety and mood swings are few of the many cognitive and behavioural symptoms of this disorder. This topic is particularly studied extensively as a single exact cause isn’t identifiable and neither is it curable, however genetics and environmental factors have been studied to increase the chances of ADHD.
The most robust evidence for the association for ADHD in terms of inherited factors, has been shown for a dopamine D4 receptor gene (DRD4), which is a receptor which binds both the neurotransmitters dopamine (plays a role in pleasure, mood, learning) and norepinephrine (which plays a role in a person’s mood and ability to concentrate) and the seven-repeat allele of this functional polymorphism (different forms of a gene, that can influence gene functions) has been associated with ADHD. Other functional polymorphisms also have played a role in relation to dopamine and therefore have been associated with ADHD causing candidates.
The other side of it lies the contribution of the environment. Firstly, maternity reports and urinary cotinine levels in mothers have shown a link between maternal cigarette smoking and offspring ADHD. Secondly, heavy material exposure to alcohol can cause foetal alcohol syndrome which apart from the biological symptoms also shows behavioural aspects of inattention and hyperactivity. Furthermore, significant maternal stress has also been associated with offspring ADHD symptoms. Although not causal, retrospective studies have shown these results.
Although there isn’t a cure for ADHD, it can be managed by treatment, either through behaviour therapy or through mediation. Stimulants are given to produce a calming effect through the increase of neurotransmitters of dopamine and norepinephrine. Therapy often involves discussing the condition with the person to help cope better. Behaviour therapy involves management of behaviour, through reward systems, especially for children.
The study of ADHD is still carried out to get a better understanding of its causes. Family and twin studies, longitudinal studies, surveys and meta-analysis of previous studies are used to examine this neurobehavioral disorder, making this an interesting concept to learn about.
Intersting articles to read:
Citation:
Thapar, Anita, et al. “What Causes Attention Deficit Hyperactivity Disorder?” Archives of Disease in Childhood, BMJ Publishing Group Ltd, 1 Mar. 2012, https://adc.bmj.com/content/97/3/260.
Image:
“Understanding ADHD.” OpenLearn, https://www.open.edu/openlearn/health-sports-psychology/understanding-adhd/content-section-0?active-tab=description-tab.
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