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Rapid response to:


Antidepressant use during pregnancy and psychiatric disorders in offspring: Danish nationwide register based cohort study

BMJ 2017; 358 doi: (Published 06 September 2017) Cite this as: BMJ 2017;358:j3668

Rapid Response:

The article research method should be more robust.

Dear Sirs and editors,
The investigation for the association between in utero exposure to antidepressants and risk of psychiatric disorders is more valuable if the article research method was more robust.
There are 6 criticisms in the research method:
1. Antidepressant use before pregnancy should be defined as prescription on any date between two years and before pregnancy day. Antidepressant use during pregnancy should be defined as prescription dispensed on any date from the day of pregnancy until delivery. The one month different must have lots of different statistics results.
2. The 1719 children with chromosomal abnormalities (ICD-10 (international classification of diseases, 10th revision) codes Q90-Q99) identified from the Danish National Patient Register should not be deleted or excluded. Since the antidepressants may induce the chromosomal abnormalities and then cause psychiatric disorders.
3. The 9745 children with missing links to their fathers should not be excluded. Since the research is on the mother side.
4. The sensitivity analysis should not be in contradiction with the former define of s tudy population. For example, “to reduce the misclassification of discontinuation of antidepressant use, we redefined antidepressant discontinuation as maternal use of antidepressant from two years to three months before pregnancy but not from three months before pregnancy until delivery”. While the study population defined as, Antidepressant use before pregnancy was defined as prescription on any date between two years and one month before pregnancy. Antidepressant use during pregnancy was defined as prescription dispensed on any date from one month before pregnancy until delivery.
5. The 2644 pregnancies in mothers with any inpatient psychiatric treatment from two years before pregnancy until the delivery should not be excluded. Since the research should not exclude severe symptoms of psychiatric disorders.
6. The research and analysis should pay attention to which type of psychiatric disorders is easy to be suffered from in all patients taking any antidepressant and a special antidepressant. Since the observational studies are valuable national and big or mass data.

Competing interests: No competing interests

07 September 2017
Xu Han-You
Clinical Institute, Department of Emergency Medicine, Nanyang Wolong Hospital, Henan Province, China.