Background: Attention Deficit Hyperactivity Disorder (ADHD) is a genetically influenced condition although indicators of environmental risk including maternal smoking during pregnancy, low birth weight and low social class have also been found to be associated with the disorder. ADHD is a phenotypically heterogeneous disorder in terms of the predominant symptom types (inattention, hyperactive-i...

BACKGROUND Attention Deficit Hyperactivity Disorder (ADHD) is a genetically influenced condition although indicators of environmental risk including maternal smoking during pregnancy, low birth weight and low social class have also been found to be associated with the disorder. ADHD is a phenotypically heterogeneous disorder in terms of the predominant symptom types (inattention, hyperactive-im...

OBJECTIVE To verify how conduct disorder and conduct problems are associated with gender, age at onset of drug use and categories of drugs used. METHOD A test of association was conducted between the presence of comorbidity and gender. Mean age of first use of each drug was compared to mean age of first arrest, of first robbery/theft, and of first drug dealing. RESULTS In this sample, appro...