048P Queen Elizabeth II Conference Centre London
Pharmacology 2015

 

Prenatal antidepressant exposure: the risk of autism spectrum disorder and attention-deficit hyperactivity disorder

 

Recent studies suggest that prenatal exposure to Selective Serotonin Reuptake Inhibitors (SSRIs) may be associated with an increased risk of Autism Spectrum Disorder (ASD) and Attention Deficit Hyperactivity Disorder (ADHD) (1,2). However, potential confounding by effects such as maternal psychiatric disorders have not been comprehensively addressed. This study is to investigate the association between prenatal SSRIs exposure and ASD/ADHD in a large public health-care system. Children who were delivered in public hospitals (2001-2012) were identified using the Hong Kong population-based electronic medical records held within the Clinical Data Analysis & Reporting System and were followed-up to 31st December 2014. Using a case-control design, we evaluated the association between ASD/ADHD and prenatal exposure to SSRIs. Further analyses using a case-time-control design (3), whereby each individual acted as his/her own control, were conducted to address potential residual confounding effects. Risks of ASD and ADHD were estimated using odds ratios (ORs) through logistic regression. 298,990 children were included in the analysis. 4,208 and 2,706 children were diagnosed with ASD and ADHD respectively. The adjusted odds ratios for ASD and ADHD were 1.37 (95%CI 0.96-1.95) and 2.16 (95%CI 1.47-3.17) respectively. In contrast, no associations were found in the case-time-control analysis (OR=0.99, 95%CI 0.73-1.33 for ASD; OR=0.76, 95%CI 0.55-1.06 for ADHD). Similar results were found for non-SSRI antidepressants.

Table 1: Results from case-control and case-time-control analyses of ASD and ADHD risk with prenatal exposure to SSRIs

 

  OR 95%CI 
Autism Spectrum Disorder (n=4,208)
 Case-control OR 1.37 0.96 1.95
 Case-time-control OR 0.99 0.73 1.33
Attention Deficit Hyperactivity Disorder (n=2,706)
 Case-control OR 2.16 1.47 3.17
 Case-time-control OR 0.76 0.55 1.06

 

This study does not support the hypothesis that prenatal SSRIs exposure increases the risk of ASD/ADHD in children. Rather, our results suggest that the previously-reported risk of ASD/ADHD with prenatal SSRI exposure may be a consequence of confounding factors such as maternal characteristics and/or genetic risk.

(1) Man KK et al. (2015). Neurosci Biobehav Rev. Feb;49:82-9

(2) Clements CC et al. (2014). Mol Psychiatry. 20(6):727-34

(3) Suissa S. (1995). Epidemiology. 6(3):248-53