Improving Mental Health With Precision Medicine

An Interview With Harris Eyre

Tell us a little bit about yourself?

I’m an Australian, currently living in Houston, Texas. My mission is to end the ‘one size fits all’ approach to mental health issues which is why I co-founded CNSdose, a company focused on the personalisation of medication.

Why do you do what you do?

I think that we can do better in the mental health field. It is my frustration with the current standard of care that drives me to find new, accessible and evidence-based ways to help lots of people. While there are major issues, there are major opportunities.

Major depression is devastating to individuals of all ages, families, communities and workplaces, affecting 300 million people worldwide. In the case of moderate to severe depression, antidepressant medications are the mainstay of care and these medicines are still prescribed through trial-and-error. The trial-and-error process works only half the time. This process leaves people feeling like guinea pigs, frustrated and demoralised…

Fortunately, there are new innovations providing hope to make this process more personalised and precise. Genetic guidance of these medicines is one example of such an innovation aka pharmacogenetics. A simple swab of the cheek quickly guides a clinician’s choice of the medication at the ideal dosage for an individual based on their DNA. These tools can reduce the frustration, suffering and costs of trial-and-error prescribing meaning faster recovery with fewer side-effects.

Can you provide an overview of your work in mental health?

My work in mental health revolves around developing and deploying new, personalised solutions into the clinical environment to help patients.

Let’s again take the example of antidepressants where evidence indicates that genetic factors play a critical role (42% - 50%) in determining responses to and the adverse effects of these medicines. What about the other 50%? Clearly, other biological factors (exercise habits, microbiome, immune system, etc.) also play a role in the way these medications are metabolised by the body.

In the past few years, I’ve been exploring how other ‘omic’ factors can be merged with genomics to optimise the personalisation of medication treatments. This includes looking at epigenomics, microbiomics, and digitomics. Epigenomics is the study of changes in organisms caused by modification of gene expression rather than alteration of the genetic code itself. Emerging evidence from human and animal work suggests a key role for epigenetic markers in the prediction of antidepressant response. Microbiomics is the study of microorganisms in the human gut. Digitomics is the study of the digital representation of human health from tracking outputs from smartphones and sensors (e.g. FitBit).

Why are you so passionate about precision medicine?

What’s most exciting about precision medicine is that it’s here now. It’s no longer a lofty academic concept, it’s readily available, evidence-based, easy to use and has real benefits for patients.

It is wonderful to be able to visit with clinicians and patients around the world and inform them about pharmacogenetic tools and the science behind them. It brings a new solution, hope and optimism. Moreover, tools like this empower patients with more information and data about themselves and ultimately strengthen the shared decision making they have with their doctor.

Why is your focus mental health specifically?

I’ve always been interested in how people think, why we do what we do and say what we say. The science of the brain is particularly fascinating, and we know so little about it – we know more about the surface of the moon than about the brain. Then mental health is such a huge area of need and the current standard of care, trial-and-error, is so inadequate.

To be able to use personalised genetic testing to address the trial-and-error approach to mental health medication treatment is very important to me. It can avoid or minimise the drug-drug interactions between mental health medicines and medicines for commonly co-occurring conditions (such as heart disease, anxiety and diabetes). Such drug-drug interactions can cause side effects or result in medicines being ineffective. Then I’m interested in raising awareness for medicines which actually have depression as a side effect. A recent study suggested one-third of US adults may unknowingly use medicines that can cause depression, and those rates of likely similar in New Zealand. These medicines can include proton pump inhibitors and blood pressure medicines.

 What impact do you expect precision medicine, or what is more commonly known as genetic testing, to have on cases of post-natal depression?

The impact I expect will be large. Post-natal depression is a common problem, affecting more than 1 in every 10 women within a year of giving birth. It can also affect fathers and partners. If self-help and psychological therapy are not enough to manage the issues, then antidepressant medicines may be considered. Of course, if relevant, the physician should only prescribe medicine that’s safe to take while breastfeeding.


In terms of looking at what’s closest to home, can you speak to trends or advances you are seeing in New Zealand?

An impressive development is the Te Tumu Waiora model and service ( Te Tumu Waiora is te reo for ‘To head towards wellness’ is a new model of primary mental health and addictions care and support. It aims to provide all New Zealanders experiencing mental distress or addictions challenges with access to convenient, high quality, integrated and person-centred care and support. The provision of health coaches is helpful for mothers suffering from post-natal depression. If we take the issue of antidepressant treatment for post-natal depression, a health coach can stand to encourage adherence and reiterate the need for the medicines. Adherence to antidepressants is quite poor with up to 50% of patients ceasing to take their medicine after 6 weeks, and this can result in worsening of the depression. The stopping of antidepressants can be due to a range of issues: patient factors (concerns about side effects, fear of addiction, beliefs about medication and illness, patient lower stage of change), clinical factors (lack of patient education, poor follow-up), social factors (isolation, poverty, lack of social support, low income, low educational level) or drug factors (cost, adverse effects). A health coach can help to address these issues via working with the patient, clinician and multidisciplinary treatment team.

Would you be able to share an example of a program, perhaps in NZ or overseas that you think demonstrates a big step in the right direction?

One group which I find particularly inspiring is The Center for Women’s Mental Health at Massachusetts General Hospital, affiliated with Harvard Medical School ( In particular, they focus on the premenstrual dysphoric disorder (PMDD), pregnancy-associated mood disturbance, postpartum psychiatric illness, and peri- and post-menopausal depression.

In the Australasian region, there are similar centres at the University of Melbourne-Royal Women’s Hospital ( and Monash University-Alfred Hospital (


If you would like to know more about Dr Harris’s work, you can find him on LinkedIn. You can also view the CNSdose website: