Previous studies have reported a significant loss of subjects in
the long-term follow up [4,6,27] because of the associated social
conditions. The present study included a long period after birth, which
may contribute to an important loss rate and a limitation to the study.
However, with the data obtained we can verify that this is a group
with some peculiarities in terms of socioeconomic status, psychiatric
pathology and drug use on comparison with young people with a similar
age and without antecedents. It is known that addictions, as other
psychiatric diseases, are diseases characterized by a complex interaction
between genetic [28] and environmental factors [29]. Nonetheless, are
the socioeconomic conditions in which these subjects grew up, genetic
factors or heroin exposure in utero the causes of this trend to social
problems, drug use and psychiatric disorders? Unfortunately the small