Consanguineous marriages are those that take place between close kin or first cousins. According to a recently published research in the journal JAMA Psychiatry, children born from first cousins' marriage are three to five times more likely to get medication for mood disorders like anxiety and depression during some phase of their lives. In addition, they are two times more likely to be prescribed antipsychotic medications for managing brain disorders like schizophrenia.
Even though the researchers did not establish why the risk was there, past research has established that such children are highly likely to develop single-gene disorders like sickle cell disease, cystic fibrosis, Fragile X syndrome and Huntington's, which account for cognitive and learning impairments . These conditions stem when parents of such children inherit a specific DNA from a common grandparent.
Lifetime susceptibility to schizophrenia, depression
The researchers investigated 363,960 individuals who were born in Northern Ireland between 1971 and 1986, and lived till 2014. Immediately after a child's birth, his or her parents were asked how closely they were related to each other. The mental health of the participants was examined by analyzing their prescriptions for antipsychotic and antianxiety and antidepressant medications between 2010 and 2014.
As per research, nearly one in 10 children had parents who were closely related or were second cousins. On average, the lifetime risk of developing schizophrenia is in the range of 0.3 to 0.66 percent, whereas for children of cousins, it is double. This implies that there is a 99 percent chance that such children will require antipsychotic medication at some stage in their lives.
For most people, the lifetime risk of developing depression is 10 percent, but in case of children of cousins, it is three times more. This is equivalent to 70 percent chances of them being never prescribed antidepressants.
The authors added that single-gene disorders might be rampant in the isolated communities even when there is no breeding among the relatives. According to them, first cousins desirous of getting married should receive genetic counseling and know-how of the risk factors involved.
Prior to this study, a research was published in 2013 by the universities of Leeds and Bradford which suggested that children of first cousins are two times more susceptible to developing deadly congenital defects like Down's syndrome, and heart and lung problems.
Consanguineous marriages and mental health of the offspring
Consanguineous marriages have been in practice since time immemorial in the Middle East, West Asia and North Africa as well as in the emigrant community from these regions which is residing in Europe, Australia and North America. Studies in the past have established that in comparison to normal marriages, the consanguineous ones have prevalence of mental disorders like social phobia, generalized anxiety disorder, specific phobia, major depressive disorder and personality disorders.
Children born out of such wedlock are at a higher risk when parents move to a different country to pursue their dreams. The cultural difference and social unacceptability can take a toll on a child's mental and physical health leaving him or her with a sense of displacement and isolation, giving rise to feelings of low self-worth, hopelessness and inadequacy, which can lead to depression.
Way to sound mental health
Consanguineous couples must be provided with premarital and preconception counseling, so that they are completely aware of the impending risks. School- and community-based programs should be made available to their children for better assessment of mental health. Awareness programs should also disseminate important information considering this section of the society. Timely diagnosis can be instrumental in safeguarding mental health of the vulnerable population.