Saturday, 23 September 2017

Pregnancy antidepressant use and offspring outcomes beyond autism?

I'll say one thing for the British Medical Journal (BMJ), they don't seem to be afraid to cover important issues relating to the *possible* "reproductive safety of drugs" [1] as per their publication of yet another paper looking at antidepressant use during pregnancy and offspring outcomes published by Xiaoqin Liu and colleagues [2]. This follows another paper published in the BMJ and covered on this blog a few weeks back (see here).

The specific class of drugs being examined again are, as I mentioned, the antidepressants and based, yet again, on data from one or more of those wonderful Scandinavian population registries in relation to how pregnancy use of antidepressants *might* impact on risk of risk of various psychiatric disorders in offspring. A diagnosis of autism spectrum disorder (AD) has been a primary focus of previous research in this area; particularly the question of whether the medicines themselves or the condition(s) that the medicines are used for (i.e. maternal psychopathology) might be the more important variables related to enhanced offspring risk of autism. The last paper covered on this blog by Rai and colleagues [3] very cautiously suggested that: "The results of all these analyses, which used different assumptions, seemed to be consistent with each other, suggesting that the association between in utero exposure to antidepressants and autism might not be fully explained by confounding." Cautiously...

This time around the net was widened from just looking at autism as an offspring outcome to "overall risk of psychiatric disorders" including: "autism spectrum disorder... mood disorder... neurotic, stress related, and somatoform disorder... behavioural and emotional disorder... and mental retardation." I might add that these are the authors words not mine and diagnoses were based on ICD-10 criteria and codings.

Looking and following some 900,000 children born between 1998 and 2012 in Denmark until 2014, researchers categorised participants according to their pregnancy antidepressant exposure(s): "unexposed, antidepressant discontinuation (use before but not during pregnancy), antidepressant continuation (use both before and during pregnancy), and new user (use only during pregnancy)" and looked at the frequency of those conditions included for study.

Results: some 2% of children were born to mums who used an antidepressant during pregnancy (n=21,063). Various types of antidepressants were used but the majority were prescribed SSRIs (Selective Serotonin Reuptake Inhibitors) either alone (monotherapy) or in conjunction with other non-SSRI medication.

"We observed increased risks of psychiatric disorders in all three groups of antidepressant users (discontinuation, continuation, and new user groups), compared with the unexposed group." This itself is an important finding but does not yet disentangle whether medicine use or the reason(s) for medicine use might be the more important variable. Then: "we observed an increased risk of psychiatric disorders in children whose mothers continued antidepressant use during pregnancy, compared with mothers who discontinued." Such a statement potentially edges a little closer to some influence of pregnancy antidepressant use on offspring outcomes but, and it is an important but: "These associations could be attributable to the severity of the underlying maternal disorders in combination with in utero antidepressant exposure." In other words, those mums who needed to continue antidepressant use throughout pregnancy probably had to do so because their symptoms either returned or were not controlled properly when medication is not in place. This might imply that more serious maternal psychiatric disorder could be a variable in any enhanced risk of offspring psychiatric disorder.

When it came to looking at specific diagnostic labels for offspring, all but "mental retardation" (I prefer the term learning disability) seemed to be elevated alongside "in utero exposure to antidepressants." The conditions with the highest risk were the mood disorders including diagnoses such as clinical depression and bipolar disorder. Given that antidepressants are typically (but not exclusively) used to treat/manage mood disorders, such a finding of maternal mood disorder potentially transmitting down into offspring mood disorder receives further credence from such results.

The Liu paper and accompanying editorial grapple with the question of whether the *possible* risks from pregnancy use of antidepressants on offspring merit a change to guidance on their use at such a critical time. As I've mentioned on other occasions discussing this topic, antidepressants are not typically just dispensed willy-nilly without appropriate clinical indication. They provide an important service in controlling various types of symptoms; pertinent to the idea that uncontrolled depression during pregnancy for example, can have all-manner of negative outcomes. As all medicines do, yes they may have side-effects but these need to be weighed up against perceived benefits, taking into account any important influence on the developing child. Indeed, the authors note: "any final decision on antidepressant continuation should be individualised and made jointly by health professionals and patients."

And whilst I've mentioned pregnancy antidepressant use and offspring autism risk, yet another review paper enters the scientific fray [4]...


[1] Nordeng H. et al. Prenatal exposure to antidepressants and increased risk of psychiatric disorders. BMJ. 2017; 358: j3950.

[2] Liu X. et al. Antidepressant use during pregnancy and psychiatric disorders in offspring: Danish nationwide register based cohort study. BMJ. 2017; 358: j3668.

[3] Rai. D. et al. Antidepressants during pregnancy and autism in offspring: population based cohort study. BMJ. 2017; 358: j2811.

[4] Andalib S. et al. Maternal SSRI exposure increases the risk of autistic offspring: A meta-analysis and systematic review. Eur Psychiatry. 2017 Jun 20;45:161-166.