Even though Attention Deficit Hyperactivity Disorder is estimated to be 70-90% heritable, full understanding of the etiology of this disorder must be framed under a bio-ecological developmental model that contemplates the gene/environment interaction as a matrix of risk/resilience factors. Family psychosocial variables, parenting stress and parental discipline have been identified as environmental risk factors related to the course of the disorder. However there is a lack of research exploring causality and interrelations between these variables and ADHD. This was the aim of the present study, to investigate the effect of family environment in the onset and course of ADHD.

One hundred and fourteen families with children with ADHD participated in the study. Parents completed a Semi-Structured Interview, the Parenting Stress Index Questionnaire (Abidin 1990) and The Parenting Scale (Arnold, O'Leary, Wolff, & Acker, 1993) that measures parents’ dysfunctional discipline practices.

Structural equation analysis was fitted to the relation of family variables and ADHD. The analysis showed interrelationship among family psychosocial variables, parenting stress and discipline practices.

Although future research should make use of longitudinal design to untangle the issues of causal directions between these constructs and potential transactional processes, our findings evidence that interventions in ADHD should incorporate a parenting training component focused on behaviour management strategies and on effective dimensions of parenting.