DISORDE ATTENTION DEFICIT HYPERACTIVITY DISORDER

Disorder, attention deficit hyperactivity disorder (TDAH )is a behavioral syndrome with neurobiological bases and a strong genetic component. It is a very prevalent disorder estimated to affect between 5% and 10% of child population, being about 3 times more common in males. No differences have been demonstrated between different geographical areas, cultural or socioeconomic groups. Represents between 20% and 40% of consultations in the services of child and adolescent psychiatry.

 
It is a neurological behavioral disorder characterized by moderate to severe distractibility, short attention span, restlessness, emotional instability and impulsive behaviors. It has a very high response to treatment, even if accompanied by high rates of psychiatric comorbidity. According to the Diagnostic and Statistical Manual of Mental Disorders (DSM-IV): "Typically, symptoms worsen in situations that require attention or sustained mental effort or that lack intrinsic appeal or novelty (eg., Listen to teacher in class, do homework, listen to or read long texts, or working on monotonous or repetitive tasks). "

This neurobiological dysfunction was first recognized in childhood. However, to the extent that it was better understood, recognized its chronic nature, since it persists and manifests itself beyond adolescence. Studies of long-term monitoring has shown that between 60% and 75% of children with ADHD continues to have symptoms into adulthood.
Historically, this disorder has been given different characterizations and countless denominations, which make the queries in the literature (see table). It added that the acronym TDAH (Attention-Deficit Hyperactivity Disorder) is widely used to refer to this syndrome.

Causes
This is a neurobehavioral disorder of primarily genetic origin. Have demonstrated hereditary factors (ie, inherited, not acquired in the course of life) in 80% of cases. Studies show that there is a familial transmission of the disorder. In contrast, note that the estimated contribution of non-hereditary factors in all cases of TDAH is only 20%. To explain this minority of cases has been proposed intervention are multifactorial, involving genetic factors but also in combination with environmental factors. The influence of congenital causes act during gestation (ie, not inherited, with the participation of genetic or environmental factors in varying proportions), such as in utero exposure to nicotine, are not considered as important as a few decades ago. It is noteworthy that even in cases that at first glance be attributed to environmental factors (such as just mentioned), the intervention of purely genetic factor offers a plausible explanation. In that sense, it has been established that smoking rates among women with TDAH are several times higher than in the general population. And because of this, these women are also more likely to smoke during pregnancy as a corollary; the presence of TDAH in children to be born again refers to genetic factors