A retrospective study has shown that children born to consanguineous parents are significantly more likely to develop psychoses and mood disorder according to a study recently published in JAMA Psychiatry.
Researchers performed this population-wide cohort study on 363,960 subjects born in Northern Ireland between January 1, 1971 and December 31, 1986, and who were still alive and residing in their home country as of 2014. Of all subjects, 52.5% were male, and 0.2% were identified as being born to consanguineous parents. Using multilevel logistic regression models and adjusting for poor mental health factors, researchers found children of parents who were first cousins were 2.13 times as likely to use antipsychotics (95% CI, 1.29-3.51) and 3.01 times as likely to use antidepressants or anxiolytics (95% CI, 1.24-7.31) as children of parents who were not related.
Scientists collected complete data on all relevant variables. The initial population of 447,452 births between 1971 and 1986 was drawn from the Child Health System data set. During house calls, which were routine for 2 weeks after childbirth, officials identified consanguinity through questions asked of the parents. An estimate of ill mental health stemmed from whether the subject had received psychotropic medication between 2010 and 2014, with ever or never use determining the primary analysis and a minimum of 3 months’ prescriptions used for more sensitive analyses. Researchers estimated common mood disorders based on usage of anxiolytics or antidepressants, and estimated psychoses based on usage of antipsychotic drugs.
Limitations of this study include the lack of usage indications or diagnosis codes in prescription data, as well as the possibility of inaccurate answers to questions about consanguinity. Other limitations include mortality bias and a lack of information on the mental health of subjects’ parents.
Researchers conclude that “[a] child of consanguineous parents is at increased risk of common mood disorders and psychoses.”
Maguire A, Tseliou F, O’Reilly D. Consanguineous marriage and the psychopathology of progeny: a population-wide data linkage study [published online April 4, 2018]. JAMA Psychiatry. doi: 10.1001/jamapsychiatry.2018.0133