P-264 - Intra-Familial Study of Pregnancy Complications in Attention Deficit Hyperactivity Disorder

Abstract

Introduction:

Epidemiological studies show that the variance in ADHD phenotype has a strong genotypic (75 to 80%) and environmental (10 to 25%) contribution. the environmental contribution is mainly due to non-shared environmental factors rather than shared environmental factors.

Objectives:

Case/control epidemiological studies are unable to distinguish between shared and non-shared environmental factors. Our intra-familial design reduces the number of confounding factors, thus giving a more reliable picture of the environmental and genotypic contributions to the phenotype.

Aims:

To compare incidence of Pregnancy, Labor, Delivery and Neonatal Complication (PLDNC) between children with ADHD and their unaffected siblings matched for age and gender.

Methods:

Children with ADHD were recruited at the Douglas Mental Health University Institute the Kinney Medical and Gynecological Questionnaire and the McNeil-Sjöstrom Scale were used to assess incidence of PLDNC. the study had one hundred and sixteen sibling pairs (n = 116) and a Mixed-Model Analysis of Variance (MMANOVA) was carried out.

Results:

Rank of birth and gender were significantly different between the two groups and these were taken as covariates. There was a significant difference in PLDNC between the two groups (F = 4.49, df = 1, p = .03). However, there was no significant interaction between the different stages of PLDNC and presence of ADHD.

Conclusions:

PLDNC appear to be among the non-shared environmental factors implicated in ADHD. Children with ADHD have a higher prevalence of overall complications during pregnancy as compared to their non-affected siblings, and the period surrounding pregnancy might be of particular relevance to the aetiology of ADHD.