Why are mental health problems hereditary

Are Mental Disorders Hereditary?

Genetic researchers have shown that over one hundred different genes are involved in the inheritance of schizophrenia.

A few years ago, heated discussions were held about the question of whether our genes or the environment are the cause of mental disorders. It is now clear that both genetic makeup and environmental conditions are involved in the development of mental disorders.

With the help of Family, twin and adoption studies as well as molecular biological laboratory methods, international scientists try to identify the genes for mental disorders such as schizophrenia, bipolar disorders, depression, dementia, anxiety disorders or attention deficit and hyperactivity disorder (ADHD). But apparently there is not just one gene, but rather many genes that contribute to disease development. For example, over one hundred genetic locations have already been identified that are associated with the development of schizophrenia.1

The same genes are involved in several diseases

So far, the researchers have been able to gain one interesting finding from their investigations: some of the ones that contribute to the risk of disease Genes found them equally in very different disorders such as schizophrenia and bipolar disorder. Clear genetic similarities were also found between depression and bipolar disorder or schizophrenia, and between bipolar disorder and ADHD.2

Borderline personality disorder appears to be under the same genetic influence as other personality disorders. Study results have shown that families who have anxiety disorders are also more likely to have unipolar depression. The same genes are partly involved in both disorders. These results show that mental illnesses are much more closely related than previously thought.

The susceptibility to mental disorders is increased

The scientists recorded, among other things, deviations in the genes that control the flow of Calcium ions in the brain regulate. Calcium plays an important role in communication between nerve cells. Possibly this change makes people more prone to mental disorders. So far, no one has been able to predict with certainty who will develop schizophrenia or depression and who will not. Many people carry some of these genes, but most of them never develop a mental disorder. In the future could Genetic analysis help to secure the diagnosis and provide starting points for new, "tailor-made" therapies.

Is there a connection between "genius" and "madness"?

The popular saying goes that “genius” and “madness” are close together. But what is it about this saying? Scientific studies have indicated that people with bipolar disorder as well as healthy siblings of schizophrenic and affective patients more often in creative professions work.3 Conversely, however, creative people were not diagnosed with psychosis more often - with two exceptions: writers were generally more affected by mental disorders and people in artistic professions were also more likely to have bipolar disorders.4 However, it remained unclear whether this connection was genetic or based on shared environmental influences.

Extensive genetic analyzes have recently confirmed the connection between creativity and mental disorders. Researchers examined the genes of 86,300 Icelanders, including more than a thousand artists, dancers, musicians, writers and actors. These were more likely to have genetic traits associated with an increased risk of schizophrenia and bipolar disorder than people in non-creative professions. The intelligence quotient and level of education had no influence on the relationship.5

1Schizophrenia Working Group of the Psychiatric Genomics Consortium. Biological insights from 108 schizophrenia-associated genetic loci. Nature. 2014; 511: 421-7
2Cross-Disorder Group of the Psychiatric Genomics Consortium. Genetic relationship between five psychiatric disorders estimated from genome-wide SNPs. Nat Genet. 2013; 45 (9): 984-94
3Kyaga S, Lichtenstein P, Boman M, et al. Creativity and mental disorder: family study of 300,000 people with severe mental disorder. Br J Psychiatr. 2011; 199: 373-9
4Kyaga S, Landén M, Boman M, et al. Mental illness, suicide and creativity: 40-year prospective total population study. J Psychiatr Res. 2013; 47: 83-90
5Power RA, Steinberg S, Bjornsdottir G, et al. Polygenic risk scores for schizophrenia and bipolar disorder predict creativity. Nat Neurosci. 2015; 18: 953-5