Risk factors and early precursor symptoms of attention deficit/hyperactivity disorder

Abstract

Multiple interacting factors contribute to the pathogenesis of attention deficit hyperactivity disorder (ADHD). Risk factors of ADHD comprise genetic as well as environmental factors such as socioeconomic status or maternal substance abuse. However, as some environmental factors could result from a parental genetic disposition for ADHD, a clear distinction between the impact of genetic and environmental factors is only possible to a limited extend and not necessarily reasonable. Because of the complex interplay of multiple independent risk factors, a dimensional view of ADHD begins to prevail in contrast to treating ADHD as a categorical entity. This review provides an overview of current knowledge of risk factors and early precursor symptoms of ADHD.