The genetics of having multiple mental health conditions

Posted on by Jeanette Mostert

We know that psychiatric conditions have a strong genetic component. This means that genes play an important role in determining an individual’s risk or vulnerability to develop a psychiatric condition. However, there is evidence that there are genetic variants that increase the risk for multiple psychiatric disorders. This is called pleiotropy. Researchers of the “Cross-Disorder Group of the Psychiatric Genomics Consortium” have searched the entire genome of 727,000 individuals (of whom 233,000 were diagnosed with a psychiatric disorder) to identify genetic variants with such pleiotropy.

The researchers found one particular gene – called DCC – that increases vulnerability for all eight disorders that were investigated: ADHD, autism spectrum disorder, anorexia nervosa, bipolar disorder, major depression, obsessive compulsive disorder, schizophrenia and Tourette syndrome.

They also found more than 100 genetic variants that predispose to at least two psychiatric disorders, and around 20 variants that are associated with four or more. This means that the genes that contain these variants can be interesting to further understand why certain individuals are more vulnerable to develop psychiatric illnesses than others.

One of the researchers, professor Bru Cormand, explains more about this research in this blog.

Further reading: Cross-Disorder Group of the Psychiatric Genomics Consortium (2019): Genomic Relationships, Novel Loci, and Pleiotropic Mechanisms across Eight Psychiatric Disorders. Cell, 179(7): 1469-1482.e11. 

Professor Cormand is involved in the CoCA research consortium where he investigates the genetic overlap between ADHD, major depression, anxiety disorder, substance use disorder and obesity. To read more about this, see for instance this other blog by him and dr. Judit Cabana Dominguez.

The genetic architecture of the brain

Posted on by Jeanette Mostert

Genes play a big role in determining the architecture of our brain: the way it’s folded, the thickness of the outer layer, and the way different brain areas are connected. By combining data from all over the world, a large collaboration of researchers from the ENIGMA consortium has now identified almost 200 genetic variants that are involved in this brain architecture. These findings can help us to further understand the genetics of brain disorders. 

Our genes contain the blueprint of our bodies. They contain information about how our cells function, and they determine for instance the colour of our eyes and hair, or whether we like cilantro (coriander) and bitter tastes. For some traits we know very well how they are influenced by genes. Eye color for instance is coded by only a few genes. But for many other traits such as height and personality, many different genes are involved. In addition, other (non-genetic) factors also influence these traits, such as malnutrition that can cause stunted growth.

The architecture of the brain is influenced by a large numer of genes, of which we still know very little. To investigate this, researchers combined genetic data of over 50.000 individuals with MRI-data. MRI-scans can show in detail the thickness of the outer layer of the brain, where all the brain cells are (also called the grey matter). They can also be used to measure how much this layer is folded, which gives information about the total surface of this outerlayer. This brain architecture is unique to every individual. The extent of the folds and the thickness of the outer layer have previously (in other research studies) been linked to cognitive abilities and various neurological and psychiatric disorders, such as Alzheimer’s disease, schizophrenia, depression, autism, and ADHD. It is therefore helpful to understand the genetics of this architecture, because it will help us to better understand the genetic mechanisms of these conditions.

The findings from this research study are also explained in this video:

This important research can only be done by combining a lot of data and collaborating with a large number of scientists and institutes. The ENIGMA consortium has been set upt to facilitate this kind of world-wide collaboration. The research that has now been published is the combined effort of more than 360 scientists from 296 departments across 184 different institutions and universities. They also made their results downloadable so that everyone who is interested can have a closer look.

The full publication can be found here: https://science.sciencemag.org/content/367/6484/eaay6690

See also our previous blogposts about these topics:

 

 

 

These are the world’s most high ranking experts on ADHD

Posted on by Jeanette Mostert

Who are the most knowledgeable people about ADHD in the world? According to the website expertscape.com, these are professors Stephen Faraone (SUNY upstate University), Samuel Cortese (University of Southampton) and Jan Buitelaar (Radboud University Nijmegen).

What’s more, several scientists who are involved in our research consortia that investigate ADHD (i.e. Aggressotype, CoCA, IMpACT, Eat2beNICE) are top-ranked in this list of more than 30.000 possible experts in the field. These include Stephen Faraone, Jan Buitelaar, Philip Asherson, Barbara Franke, Joseph Antoni Ramos-Quiroga, Henrik Larsson, Catharina Hartman and Pieter Hoekstra. What this means is that the ADHD research that we do, and that is often reported on in this blog, is lead by the world’s top ADHD experts.

adhdexperts_pic
‘Our’ top-ranked ADHD experts. From left-to-right: Stephen Faraone, Jan Buitelaar, Philip Asheron, Barbara Franke, Joseph Antoni Ramos-Quiroga, Henrik Larsson, Catharina Hartman, Pieter Hoekstra.

How is an expert defined?

The website expertscape was started by John Sotos when he was looking for an expert on Parkinson’s disease to treat his uncle. This turned out to be more difficult than he thought. As John Sotos was a doctor himself, he luckily had a large network of doctors that he could contact about this. But this made him realise that people who don’t have such a network, would not be able to find out who the most knowledgeable persons are on a particular topic. He therefore created this website expertscape.com

The way the website works is quite simple: it searches for academic, peer-reviewed publications by a certain person on a certain topic. The more someone has published on a topic, the higher this person is ranked. Thus,  “[a]n expert is not just someone who knows a lot about a particular topic. We additionally require that the expert write about the topic, and be involved at the leading edge of investigation of the topic.”

This means that the site is actually not a very good tool to find a good doctor. As the website acknowledges “a great doctor has many important qualities beyond expert knowledge of your very specific medical condition.” However, it does mean that the website is pretty good at providing a simple overview of who has a lot of scientific knowledge about a specific topic.

So are they really experts?

In the past years I have met with most people in the top of this list, and I dare say that they are very knowledgeable indeed. Each of them has been working in the ADHD field for a considerable amount of time and has added important new insights into ADHD through research and publications. What I find most striking from this list however, is that most of these experts work together in consortia and international networks. And that is how the field really moves forward: by combining the knowledge of all these experts.

Several of these experts have also written for this blog:

 

Source: http://expertscape.com/ex/attention+deficit+disorder+with+hyperactivity

 

This blog was written by Jeanette Mostert. Jeanette studied brain connectivity in adult ADHD during her PhD. She is now dissemination manager of the international consortia CoCA and Eat2beNICE.