What makes some of us more likely to drive over the speed limit, participate in extreme sports or make decisions that can impact health over time? Risk-taking behavior has distinct subtypes (for example disinhibition, sensation seeking, calculated risks, impulsivity) that develop due to the complex interplay of different factors: our lifestyle and environment, our personal susceptibility (genetic and biological variants) and a wide range of psychological effects.

In the study of Strawbridge and colleagues (2018) the goal was to identify genetic determinants of this trait. This approach has the potential to improve our understanding of impulsive behavior across different psychiatric disorders. It can also help later on to explore the possible overlap between mental illnesses and physical health.

„Would you consider yourself a risk taker?” This was the question posed to 116,255 participants, aged 40 to 69, from the UK Biobank project, a large population cohort containing a wide range of sociodemographic and medical information. Roughly one-quarter answered yes, they were the ’risk takers’ group.

A subset of participants took part in a prolonged follow-up occasion as well, where the same question was asked enabling an assessment of response consistency. Reproducibility was quite good, 81% of all participants responded consistently, 13% inconsistently, while in 6% the data was missing.

Genetic loci associated with risk-taking behavior were explored using the genome-wide association study approach. The authors identified one potential locus on chromosome 3 (CADM2) consistently, which was previously implicated in cognitive and executive functions.

Considering the entire genome using the polygenic risk score approach, the authors found, that the genetic variants that make us risk-prone also make us more likely to develop mental illnesses, such as bipolar disorder, schizophrenia, attention-deficit hyperactivity disorder, and post-traumatic stress disorder.

This trait has not only significant positive genetic correlations with a range of mental health disorders, but also with smoking, lifetime cannabis use and body mass index (BMI). The latter implies the possibility that this finding could be followed up in a study exploring the nutritional aspects of impulsivity as well.

Overall, using dimensional approach for traits (from “normal” to pathological) rather than discrete diagnostic categories could be helpful for finding the common ground in the neurobiological underpinnings across psychiatric disorders. From this point of view, risk-taking behavior is also a complex and important phenotype for investigations.

You can find the full research article here.

Strawbridge, R. J., Ward, J., Cullen, B., Tunbridge, E. M., Hartz, S., Bierut, L., Horton, A., Bailey, M. E. S., Graham, N., Ferguson, A., Lyall, D. M., Mackay, D., Pidgeon, L. M., Cavanagh, J., Pell, J. P., O’Donovan, M., Escott-Price, V., Harrison, P. J., & Smith, D. J. (2018). Genome-wide analysis of self-reported risk-taking behaviour and cross-disorder genetic correlations in the UK Biobank cohort. Translational Psychiatry, 8. https://doi.org/10.1038/s41398-017-0079-1

This was co-authored by  Tünde Kilencz, a psychologist and research assistant at Semmelweis University, Department of Psychiatry and Psychotherapy in Budapest, Hungary.

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The human gut is colonized by microorganisms in a similar number as the cells of the human body.

“Microbiota” refers to these microorganisms, and it maintains a symbiotic relationship with the host, contributing to essential functions such as food digestion, energy harvest and storage, the function of the intestinal barrier, and the immune system and protection against pathogenic organisms. Prenatal and postnatal factors can alter the composition of the microbiota, such as stress and diet or the use of antibiotics (see image).

Prenatal and Postnatal factors influence gut-brain axis and mental healthFor instance, stress during pregnancy can alter the composition of vaginal microbiota, which affects the composition of the microbiota of the newborn and is related to gastrointestinal (GI) symptoms and allergic reactions. Interestingly, there is a bidirectional communication between the GI tract and the central nervous system (the gut-brain axis) that involves neuronal and metabolic pathways, immune and endocrine mechanisms. Changes in the composition of the microbiota can lead to altered development of the brain and increased risk of psychiatric and neurodevelopmental disorders, such as anxiety, depression and autism (see image).

Depression is one of the most recurrent stress-related disorders that highly impacts the quality of life. Fecal samples of patients with depression have a decreased microbial richness and diversity than controls. The use of probiotics have been shown to help with sad mood and negative thoughts, which may be a potential preventive strategy for depression.

Autism is characterized by impaired communication, poor social engagement and repetitive behaviours, with frequent GI symptoms. We know that the bacteria composition is more diverse in autistic individuals than in unaffected subjects.

For other psychiatric disorders, such as Attention deficit/hyperactivity disorder (ADHD) and Schizophrenia, there is indirect evidence for a role of the microbiota, but more studies are needed.

This connection between the gut and brain is two way communication, and is known as “The Gut-Brain Axis.”

Our knowledge of the impact of gut microbiota on brain function is growing fast, which may pave the way to possible applications for the treatment of psychiatric and neurodevelopmental disorders.

Authors Judit Cabana, Bru Cormand, and Noelia Fernandez Castillo are in the Department of Genetics, Microbiology & Statistics, University of Barcelona, Catalonia, Spain

More information can be found in: Felice VD, O’Mahony SM. The microbiome and disorders of the central nervous system. (2017) Pharmacol Biochem Behav. Sep;160:1-13.
https://www.ncbi.nlm.nih.gov/pubmed/28666895

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Nutrition as part of the solution to the mental health crisis!

Mental illness affects one in five people globally and, despite the wide availability of solid empirically supported therapies, these statistics are not getting any better. We appear to have reached an impasse improving outcomes, despite improvements in other areas of medicine.

We need to explore new avenues.

There has been a small explosion in research using nutrients for the treatment of mental illness over the last decade. The general premise is that our brains need nutrients to function and chemicals that are essential for good mental health, like dopamine and serotonin, require micronutrients, like vitamins and minerals.

Preliminary clinical trials are putting micronutrients and good nutrition on the map as essential for optimal brain health. These trials show that giving more nutrients than what is obtained through diet alone can have a positive impact on serious conditions, like Attention-Deficit/Hyperactivity Disorder (ADHD)(1), autism(2) or anxiety(3). Along a similar vein, other studies are highlighting that improving diet alone can also improve mental health. By showing that manipulation of the amount of nutrients one consumes can influence mental health, the research demonstrates that the nutrients these participants were receiving prior to these interventions were not adequate to meet their mental health needs.

Beyond a ‘sledge hammer’ solution

Nutrition and mental healthAt the moment though, in the area of nutrient supplementation research, we are taking a sledge hammer to the problem. We give everyone a broad array of nutrients and see who gets better. That’s been a good start in that significant changes in many areas of functioning have been observed in many people, but the problem is that we each have unique nutrient requirements.

This approach of “one size fits all” will only go so far. Some people don’t respond. Some people only get marginally better. Why? Can we use genetic and nutrient testing to determine the optimal dose and nutrients that someone may require to get better based on their individualized profile? Can we use microbiome analyses to determine what microbial strains are required to best heal the gut to optimize absorption of nutrients? Current and future technologies should allow us to greatly expand the number of people who benefit from a nutritional approach.

Can this research also be used to target our food choices? To date, nutritional value is not the primary motivator in food processing. Agricultural practices tend to prioritize food storage, growth rates, transportability, shelf life, colour, shape and size above nutrient content. Could scanning of nutrient levels of fruits and vegetables using your mobile phone bring focus to the importance of the nutrient quality of our food such that this becomes the priority of consumers over aesthetic qualities or price?

Food or medicine?

Some challenges lie ahead in access to nutrients. As soon as nutrients are proven to have therapeutic benefit, legislation in some countries requires that they be treated as medicines. In other cases, dose alone can affect classification as a supplement or medication. This means as the evidence for efficacy increases, accessibility to the general public will be reduced as the ministry may insist that nutrients be accessible only by prescription.

Based on the medical model, there is a belief that pills that improve health comes with side effects that must be carefully monitored and controlled. To date, our research has shown minimal to non-existent side effects from the nutrient combinations we have studied. Moreover, physicians are currently not well placed to prescribe nutrients because so few have training in nutrition.

Government has the power to ensure legislation allows easy access to nutrients and permits health claims to be made based on good science. Such legislation could ensure that nutrients are easily available due to the very low risk associated with consuming nutrients as compared with pharmaceutical drugs.

Further challenges

Some companies sell nutrient products that optimize profit over health benefit. This may result in cutting corners, not using minerals that have been well chelated, not using the most bioavailable forms of vitamins. This will impact efficacy. It will be a challenge to ensure that nutrients designed for improving mental health are not compromised. Snake oil salesmen are never too far away.

Ensuring good access to nourishing food will also be a challenge. The prevailing mindset is that good food is expensive. However, this is true only if one doesn’t count the costs associated with eating poorly. We need attitudes towards food to change from providing calories to providing the essentials of health. Perhaps one day we will all come to realize that so many packaged and highly processed foods are nutritionally depleted. Ideally, if consumers would stop buying these products, changes would follow.

It is encouraging that some people can have better mental health and more fulfilling lives simply by ensuring their brains receive adequate nutrients and that they will not have to experience the side effects associated with so many medications. Perhaps mental illness will be viewed as being at least partially caused by improper nutrition, as our ancestors knew. Could such a shift influence the stigma associated with mental illness?

Valuing the role of nutrition as part of addressing our mental health statistics is part of our future. How well we can ensure that access is optimized and price is affordable will depend on good legislation, a re-evaluation of our current health care model and ensuring competing market forces don’t compromise the acceptability and efficacy of this solution.

(1) Rucklidge JJ1, Frampton CM, Gorman B, Boggis A. Vitamin-mineral treatment of attention-deficit hyperactivity disorder in adults: double-blind randomised placebo-controlled trial. Br J Psychiatry.2014;204:306-15. doi: 10.1192/bjp.bp.113.132126. Epub 2014 Jan 30.

(2) Adams JB, Audhya T, McDonough-Means S, et al. Effect of a vitamin/mineral supplement on children and adults with autism. BMC Pediatrics. 2011;11:111. doi:10.1186/1471-2431-11-111.

(3) Rucklidge JJ1, Andridge R, Gorman B, Blampied N, Gordon H, Boggis A. Shaken but unstirred? Effects of micronutrients on stress and trauma after an earthquake: RCT evidence comparing formulas and doses. Hum Psychopharmacol. 2012 Sep;27(5):440-54. doi: 10.1002/hup.2246. Epub 2012 Jul 11.

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