Paternal SSRI use linked to small increase in ADHD risk in offspring

Paternal exposure to selective serotonin reuptake inhibitors (SSRIs) prior to conception appears to be associated with a mildly increased risk of attention-deficit/hyperactivity disorder (ADHD) in offspring, according to a study.

Using data from Danish national registers, researchers looked at a cohort of 781,470 singletons born between 1996 and 2008 with follow-up throughout 2013. They assigned children whose fathers used SSRIs during the last 3 months before conception (n=7,216; 0.92 percent) to the exposed group.

The risk of ADHD in offspring in relation to paternal SSRI exposure was evaluated using Cox regression analysis.

Overall, 12,520 children were diagnosed with ADHD. The risk of ADHD was 26-percent greater in the exposed group than in the unexposed group (hazard ratio [HR], 1.26; 95 percent CI, 1.06–1.51).

When the exposure window was extended to 1 year prior to conception, paternal exposure to SSRIs during the period of 12 to 3 months prior to conception was associated with an increased ADHD risk in offspring (HR, 1.35; 1.10–1.66). Paternal use of SSRIs only during the last 3 months before conception was associated with a similarly increased ADHD risk (adjusted HR, 1.31; 0.95–1.82).

Researchers pointed out that the elevated ADHD risk associated with prenatal SSRI use of fathers was possibly partly confounded by paternal affective disorders diagnosed outside the hospital, for which the study was not able to adjust. This is because some fathers receive SSRI treatment from their general practitioners and are therefore not registered with a diagnosis of affective disorders.

A recent study has proposed that prenatal exposure to SSRIs, which may disrupt serotonergic neurotransmission in the foetal brain, is a risk factor for adverse neurodevelopmental outcomes (eg, delayed psychomotor development, altered social-emotional and adaptive behaviour) in childhood. [CNS Drugs 2016;30:499-515]