Effect of drugs of abuse on social behaviour: a review of animal models.
In order to disentangle the effects on development of prenatal drug exposure from the effects of poor prenatal care, perinatal complications, and low socioeconomic status, toddlers prenatally exposed to drugs were compared to high risk preterm toddlers of similar ethnicity and social class. Intellectual functioning and quality of play were assessed. The drug exposed toddlers had significantly lower developmental scores and less representational play. Furthermore elements of their play were characterized by the investigators as a soft neurological sign. The question of possible CNS impairment is raised.