Antidepressants taken by pregnant women mean a high risk of autism and developmental disorders for their children, especially boys. They also contribute to miscarriages, researchers from several research teams working independently found.

For the past five years or so, diagnoses of childhood mental disorders have been on the rise. Some of the most popular antidepressants – the selective serotonin reuptake inhibitors SSRIs – have been accused of contributing to their development. They cause an increase in the concentration of a very important neurotransmitter – serotonin – responsible, among other things, for the regulation of sleep, appetite, blood pressure and also mental state. Its decrease increases aggressiveness and at the same time promotes depressive attacks, hence SSRIs are used for this condition, generalised medication and neuroses.

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Two years ago, a team of researchers from the Johns Hopkins Bloomberg School of Public Health decided to check whether these initial diagnoses were indeed true. So the researchers examined hospital statistics and found 996 mothers whose children, who were between the ages of 2 and 5 years, betrayed mental and developmental disorders. The primary conditions identified by the doctors were autism, both mild and moderate, and developmental disorders such as developmental delays, usually mild. These children were included in the Childhood Autism Risks from Genetics and the Environment (CHARGE) research programme. Researchers at Johns Hopkins found that they had one thing in common – their mothers had taken selective serotonin reuptake inhibitors during pregnancy. The children’s diagnoses were confirmed several times by independent medical teams unfamiliar with the research programme to avoid confusion. The study took into account characteristics such as family history (e.g. susceptibility to psychiatric disorders, presence of autism in the family), family situation (complete families the possibility of a dysfunctional family) and the health status of both children and their parents. As it turned out, SSRI drugs were particularly harmful for boys – in the group of children diagnosed with autism, boys accounted for 82.5 per cent, while in the group with developmental disorders – 65.6 per cent. There were also girls in the study, but the effect of SSRI drugs on boys during maternal pregnancy was clearly stronger. It can be concluded that if mothers take serotonin reuptake inhibitor drugs during pregnancy, boys born from such pregnancies are three times more likely to develop autism than the control group, consisting of children of mothers who did not take such drugs. The period of greatest risk is the first trimester. Children with developmental disorders, on the other hand, are twice as likely to have developmental disorders if the mother took SSRIs during pregnancy than in the control group of children of women who did not take such drugs. Here the risk is the third trimester,” said Dr Li-Ching Lee, a psychiatrist and epidemiologist who participated in the study.

According to surveys in hospitals and treatment units, autism is currently found five times more often in boys than in girls in the USA, the researchers found. A similar result was obtained by autism researchers from the Swedish Sahlgrenska Academy. In both the USA and the European Union, the number of detected cases of autism is increasing. One has to wonder whether this is due to the increasing prevalence of SSRI drugs and their increasing availability, the researchers said.

According to researcher Dr Irva Hertz-Picciotto, from the UC Davis MIND Institute, the findings are a serious warning to women and mental health practitioners. Unfortunately, from now on, it will be necessary to weigh up whether the gain for the mother-to-be in terms of improved wellbeing and mental health means a great risk for her baby, with, after all, in many cases the treatment cannot be stopped, she added.

Worse still, as the study authors point out, maternal depression also poses a great risk to fetuses. It will now be necessary to carry out the same study only on girls in order to determine whether they are indeed more resistant to the negative effects of selective serotonin reuptake inhibitors and what this resistance consists of. It will now be very important to find out which doses of SSRI drugs cause the worst effects and which drugs in this group may pose the greatest risk. I still have too little data on this issue, especially as the dosing of the drugs is often carried out not on an individual basis, but according to the recommendations of their manufacturers on the drug leaflets, which adds to the problem, the researchers conclude.

This is not the only childhood disorder that SSRI drugs taken by expectant mothers have been blamed for creating. A team of researchers from the University of Toronto, led by Professor Amy Cheung, found that respiratory disorders in newborns are linked to these types of drugs. The disorder, known as elevated pulmonary pressure, is dangerous for young children, as it threatens their respiratory system. There is no gender distinction in this case – both newborn girls and boys are at risk.

The study was conducted both using hospital statistics and by analysing seven previous studies on the effects of antidepressants during pregnancy. Only serotonin reuptake inhibitor drugs showed a correlation with respiratory distress in newborns, also confirmed by hospital statistics. The researchers noted that of the 351 women whose babies developed such disorders, 286 were taking SSRI drugs. The period of greatest risk of developing this disorder is the third trimester of pregnancy. As the researchers note, it remains to be seen whether there is a correlation between specific SSRI drugs and respiratory disorders in newborns. As with autism, researchers and physicians still have too little data on this issue.

However, the effects of SSRI drugs may be even more dangerous. A team of researchers from the University of Montreal conducted a case study of 5124 Quebec women who miscarried pregnancies up to 20 weeks and women who carried the pregnancy to term. The reasons for the miscarriages varied, the researchers found, with a huge range from exam-induced stress to alcohol abuse after work or even a traffic accident. However, the researchers found only one regularity – a small (less than 10 per cent) distinct group were women who had miscarried pregnancies according to the doctors’ initial determinations of non-emergency. All women in this group had a diagnosis of depression or neurosis and were treated with serotonin reuptake inhibitor drugs. According to Dr Anick Bérard, who led the study, these drugs, such as paroxetine, were given in higher daily doses than drugs from other antidepressant groups. Worse still, the combination of two drugs from this group, which doctors sometimes recommend, doubles the risk of miscarriage. The greatest risk is during the first trimester of pregnancy and researchers now want to investigate which drugs could replace SSRIs in women with depression who are pregnant. As Dr Bérard notes, it can currently become quite difficult to treat pregnant women with depression.