Early risk factors for ADHD. A Northern Finland Birth Cohort 1986 study.

Attention-deficit/hyperactivity disorder (ADHD) is a neurodevelopmental disorder defined by age-inappropriate symptoms of inattention, hyperactivity and impulsivity leading to functional impairments various operational environments While it is well accepted that the disorder is highly heritable, not all the risk is genetic Studies have shown that the early risk factors of ADHD include, for example, premature birth and prenatal maternal substance use. Additionally, there are prenatal and postnatal factors that have not yet been studied or that have been studied but with inconsistent results.

This population-based dissertation aimed to investigate the relationship between ADHD and its early risk factors, focusing on prenatal maternal inflammation, prenatal maternal stress, breastfeeding and the temperament and character profiles of the offspring. The population consisted of the Northern Finland 1986 Birth Cohort. Several early life factors were associated with an increased risk of ADHD in the offspring. Unwanted pregnancy and prenatal maternal stress were associated with increased ADHD symptoms in offspring. In addition, a shorter duration of breastfeeding was associated with offspring ADHD symptoms. Furthermore, the results show that a distinct personality profile was associated with an ADHD diagnosis in adolescence.

This thesis is one of the first and so far the most representative studies of early risk factors for ADHD. The present findings may enable earlier detection of individuals with ADHD, which may allow more targeted and timely interventions to prevent the possible impairing outcomes of ADHD. Moreover, the number of ADHD diagnoses has significantly increased in Finland, and it may be over- or misdiagnosed. Identifying the risk factors for ADHD may potentially give rise to new tools for the more accurate diagnosis of ADHD in the future.