[Aspects concerning behavioural development and socialisation and how they are linked to attention deficit hyperactivity disorder].
BACKGROUND
Despite their importance, little attention has been given to the recognition of early markers of hyperactivity in the scientific literature and in everyday practice it can be difficult to separate some of the physiological behaviours displayed by older babies or preschool infants from pathological processes such as attention deficit hyperactivity disorder (ADHD), specific language impairment, autistic spectrum disorders, conduct disorders or bad habits with regard to discipline within the family context.


METHODS
Knowledge of some of the key points in behavioural development and sociability in children can help reach a correct interpretation of the manifestations observed in this age group. The development of linguistic competencies, a feeling of what is right and what is wrong, the development of an awareness of oneself and the capacity to infer that is established as progress is made in language are some of the keys to proper behavioural development and socialisation. The gene DRD4 is expressed in the prefrontal cortex and has been implicated in some subtypes of ADHD, as well as being linked to a novelty-seeking personality. Recent genetic evidence supports the notion of an association between certain polymorphisms in the DRD4 gene with resistant or disorganised bonds at early ages.


CONCLUSIONS
The detection of several dysfunctional signs related to inadequate self-control that appear during behavioural development and socialisation may provide early keys to the future development of ADHD.
Eirís-Puñal
J
J
Servicio de Neurología Pediátrica, Complejo Hospitalario Universitario de Santiago, Santiago de Compostela, A Coruña, España. jmeiris@wanadoo.es
Gómez-Lado
M
M
Castro-Gago
M
M
D001289:Attention Deficit Disorder with Hyperactivity / Q000503:physiopathology / Q000523:psychology*; D006801:Humans; D012919:Social Behavior; D012951:Socialization