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What causes mental health?

What causes mental health?

Is mental health genetic?

If someone in your family has a mental illness, you may be worried that you or your children may be affected too. But can the genes you inherited from your biological parents really have anything to do with whether or not you develop mental health problems?
According to the charity Rethink Mental Illness, most people with a a mental illness don’t actually have relatives with the same illness. Nevertheless, scientific research suggests that mental illness does have a genetic component – in other words, it can run in families (i). There’s even a name for the study of the role genetics may play in the development of mental ill health, namely psychiatric genetics.
But why should genes – little segments of DNA found in almost all human cells – have anything to do with a mental illness like depression, anxiety or schizophrenia? We know that some physical diseases are caused by changes in one or more specific genes or genetic mutations. These include: 

  • Single-gene disorders – where just one gene is mutated – such as sickle cell anaemia, Huntington’s disease and cystic fibrosis

* Chromosomal disorders (chromosomes are thread-like structures made up of DNA), the most well-known of which is Down syndrome

  • Complex disorders where two or more genes have mutations – diabetes, heart disease and many types of cancer are a few examples (other factors are usually involved in complex disorders too, usually lifestyle and environment factors)

But it seems our genes affect our minds, thoughts and emotions too, with a growing body of research finding certain genes and gene variations are indeed linked with mental health problems. This suggests that if someone in your family has a mental illness, you may be more likely to develop one too.


What is the science behind mental health?

Researchers and neuroscientists have suspected genes may play a part in the development of mental illness for decades, with some of the first studies involving twins. Comparing identical and non-identical twins is considered useful because it helps researchers understand how much genetics plays a part in mental illness and to what degree other factors – such as lifestyle and environment – are involved (that’s because identical twins have identical genes while non-identical twins share only half their genes).
For instance, one of the largest twin studies looking at the subject of schizophrenia suggests anything up to 79 per cent of the risk of developing the illness could be explained by genetic factors (ii).
Rethink Mental Illness has put together some useful information outlining the chances of two severe mental illnesses – schizophrenia and bipolar disorder – being passed down through families, based on recent studies (i). Compare the following with the one in 100 risk of someone in the general population – that is, someone who doesn’t have either condition in their family – developing either condition during their lifetime:

  • If you have an identical twin with schizophrenia, your risk is 40 - 50 in 100, if they have bipolar disorder your risk is 40 - 70 in 100.

  • If your non-identical twin has schizophrenia, your risk is 17 in 100; if they have bipolar disorder your risk is 20 in 100.

  • If one of your biological parents has schizophrenia, your risk is six in 100; for bipolar your risk is 10 in 100.

  • If both biological parents have schizophrenia your risk is 54 in 100; for bipolar disorder your risk is 40 in 100.

  • If your brother or sister has schizophrenia, your risk is nine in 100; for bipolar disorder your risk is 13 in 100.

  • If a second-degree relative – such as a grandparent, aunt or uncle – has schizophrenia your risk is three in 100, for bipolar your risk is 5 in 100.

Meanwhile back in 2013 a large-scale study involving more than 60,000 people suggested some mental illnesses that used to be thought of as entirely separate conditions may have common genetic variations in specific chromosome areas (iii). The conditions – autism, attention deficit hyperactivity disorder (ADHD), bipolar disorder, major depression and schizophrenia – were all found to share the same variations. However the researchers concluded the variations couldn’t be used to actually predict or diagnose any of the five conditions themselves.
More recently, a study carried out by Oxford University neuroscientists discovered there may be a distinct common pattern of connections in the brains of people with genes that increase their susceptibility to mental ill health (Iv). The research suggests someone’s genes may influence the way their brains are ‘wired’ during childhood, which may make them more susceptible to one or more mental health conditions when they’re older.
Despite the advances in psychiatric genetics, however, we‘ve only started to scratch the surface of how genetics and mental illnesses may be linked. The truth is we still don’t know the exact cause of most mental illnesses. But it’s becoming increasingly clear that it’s far more complex than being in possession of an inherited faulty gene.

What are the risk factors of mental health conditions?

A growing body of research is increasingly pointing towards the idea that mental illness is caused by a number of factors rather than one single cause such as genetics. This may well explain why, if you have mental illness in your family, it doesn’t mean you’ll automatically develop that – or any other – mental illness yourself too. 
Look at it this way: while some mental health problems are undoubtedly influenced by genetics, our genes most likely play a much smaller role in our mental health when compared to many other things in our lives. So what are these other factors at play?
These days, it’s thought mental illness may be caused by a combination of any number of the following:

Biological factors

Many theories have suggested mental health problems are caused by a chemical imbalance in the brain. Problems with nerve cell circuits and connections between different brain regions have been linked with mental illness, with some medicines that affect chemicals called neurotransmitters – hormones that allow brain cells to communicate with each other – having significant success with treating mental illnesses such as depression, for instance (these medicines include antidepressants called SSRIs).
Genetics is also classed as a biological factor, as are brain defects or injuries, early damage to the brain (for example, when oxygen to the brain is reduced during birth), long-term drug abuse and even certain infections that may cause damage in the brain. Biological factors also include things like exposure to toxins – lead, for instance – and poor nutrition.

Psychological factors

Psychological factors that may trigger the development of mental ill health are typically caused by negative experiences – particularly those that affect us during childhood. They include emotional, physical and sexual abuse, bereavement (the early loss of a parent, for example) and neglect.

Environmental factors

There are lots of environmental factors that can contribute towards mental illness, including those that affect our relationships, where we live and where we work. Examples include loneliness, a death in the family, divorce, relationship break-ups, poverty, unemployment, changing jobs or, for children, starting a new school.
Children who grow up in dysfunctional families may be more susceptible to developing a mental illness , including those whose parents had problems with alcohol or substance misuse. Social expectations can also cause stress, low self-esteem and anxiety (the pressure to do well at school, to look a certain way or to fit in with a certain group, for instance).
To sum up, scientists these days are more likely to think that mental ill health is triggered by a number of factors rather than being entirely an issue of genetics. Of course we know genes that are involved in mental illness are passed down through families. But the smart money now backs the idea that it’s those other factors – psychological and/or environmental – that trigger mental illness in someone with an inherited susceptibility.

How to protect your mental health

Having a mental illness in your family doesn’t guarantee you’ll be affected by it too, but that probably won’t stop you worrying about it. It does, however, give you the opportunity to take positive steps towards protecting your mental health, and make developing a mental illness less likely. Here are some of the things you could do:

Stay active

Getting regular exercise is important for your mental wellbeing and can help improve your mood. NHS experts recommend we should try to be active every day and do at least 150 minutes of moderate-aerobic activity such as cycling or brisk walking every week to stay healthy (v). That’s the equivalent of a 30-minute bout of activity on five days of the week. But if you find it difficult to set aside 30 minutes all at the same time you could simply do three 10-minute exercise bursts during your day.
Making time for exercise can help you feel healthier and happier in yourself and give you more energy. There’s also some evidence to suggest people who exercise regularly have more emotional resilience  – which means they are better at managing stress and dealing with setbacks – than those who are inactive (vi).

Eat healthily   

Having a healthy, balanced and nutritious diet is good for your overall health, including your mental health. It can help improve your mood and give you more energy, plus some of the nutrients found in foods such as fruit and veg may help you feel less stressed, which is a good reason for getting your 5 A Day.
The NHS recommends the Eatwell Guide as an example of a healthy, balanced diet – find out more about it by visiting It can, however, be tricky to eat healthily every day, especially when you’re busy or dealing with stressful situations. Taking a high-strength multivitamin and mineral supplement could help make sure you’re getting all the essential nutrients you need – there’s even some evidence multi-vitamins could help with stress-related symptoms (vii).
It’s also a good idea to include fish in your diet, particularly the oily type (salmon, trout, pilchards, fresh tuna, sardines, mackerel etc). Oily fish contain omega-3 fatty acids that may be helpful in reducing the symptoms of depression (viii) plus they may help you cope with the effects of stress more effectively (ix).
The NHS suggests a healthy, balanced diet should include at least two portions of fish a week, including one portion of oily fish (though girls and women of childbearing age should avoid having more than two portions of oily fish a week) (x). If you don’t like eating fish you could try taking a high-strength fish oil supplement or a vegan omega-3 supplement sourced from marine algae (these contain the same beneficial omega-3s as fish oil supplements).

Get enough sleep

If you’re not getting enough sleep, it’s unlikely you’ll cope well with stress or negative circumstances or experiences. Indeed, some experts believe getting good-quality sleep can help you cope under pressure more effectively than someone who’s sleeping poorly (xi). It is, after all, a vicious circle: if you’re having problems sleeping, it affects how you feel mentally as well as physically; and if you’re feeling below par, either physically or mentally (or both), it can affect how well you sleep.
If you’re struggling to get the sleep you need, take a look at our guide to sleep and insomnia.

Practice mindfulness

One effective way to help you cope more effectively with the things that can affect your mental health is to try being more mindful. This popular wellbeing technique aims to help you become more aware of your thoughts, feelings (both physical and mental) and environment, which could help you to notice the early signs of issues such as stress and anxiety so you can tackle them early rather than letting them develop into a problem.
If you’re interested in learning more about mindfulness there are details about some of the courses and sessions you could do on mental health charity Mind’s website

Have a chat

Talking about your feelings can help you stay mentally well too. Try talking to a friend or family member who you trust, or consider having counselling sessions with a health professional. Simply having someone who listens to you and supports you may help you deal with problems better. Connecting with other people can also give you a sense of belonging, plus talking to other people could help you keep things in perspective.

Drink in moderation

Many people drink alcohol to help them tackle negative feelings or situations. However alcohol doesn’t help in the long run, especially if you drink more than you should. According to the Mental Health Foundation, drinking is not a good way to manage difficult feelings – and when the effect of the alcohol wears off, you’ll probably feel even worse (xii). To keep your drinking at a safe level, aim to stick to the government’s recommendation of no more than 14 units of alcohol a week. Want to find out ways of cutting back? Check out our guide to alcohol misuse.

Mental health support and resources


The causes of mental ill health are complex, and even if you have a mental illness in your family it doesn’t mean you’ll automatically have a problem with your mental health too. We are, however, finding out more and more about how our genetic make-up affects many aspects of our health, both physical and emotional, with scientists regularly making new discoveries. In the meantime there are lots of things you can do to help protect your mental health, as this guide shows. For more information on issues that affect mental health, visit our pharmacy library’s mental health pages.



(i) Available online:
(ii) Hilker R et al. Heritability of schizophrenia and schizophrenia spectrum based on the nationwide Danish Twin Register. Biological Psychiatry, 2017 Available online:
(iii) [No authors listed} Identification of risk loci with shared effects on five major psychiatric disorders: a genome-wide analysis. Lancet 2013 Apr 20;381(9875):1371-1379.
(iv) Taquet M et al. A structural brain network of genetic vulnerability to psychiatric illness. Molecular Psychiatry volume 26, pages 2089–2100 (2021). Available online:
(v) Available online:
(vi) (vi) Childs E et al. Regular exercise is associated with emotional resilience to acute stress in healthy adults. Front. Physioli. (01 May 2014). Available online:
(vii) Schlebusch L et al. A double-blind, placebo-controlled, double-centre study of the effects of an oral multivitamin-mineral combination on stress. Available online: Afr Med J. (2000). 90:1216-1223.
(viii) Rondanelli, M., et al. Effect of omega-3 fatty acids supplementation on depressive symptoms and on health-related quality of life in the treatment of elderly women with depression: a double-blind, placebo-controlled, randomized clinical trial. J Am Coll Nutr. (2010 Feb). ;29(1):55-64. Available online:
(ix) Jazayeri, S., et al. Comparison of therapeutic effects of omega-3 fatty acid eicosapentaenoic acid and fluoxetine, separately and in combination, in major depressive disorder. Aust N Z J Psychiatry. (2008). 42:192-198. Available online:
(x) Available online:
(xi) Seelig A et al. Sleep and Health Resilience Metrics in a Large Military Cohort. Sleep, Volume 39, Issue 5. (May 2016). Pages 1111–1120. Available online:
(xii) Available online:



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Disclaimer: The information presented by Nature's Best is for informational purposes only. It is based on scientific studies (human, animal, or in vitro), clinical experience, or traditional usage as cited in each article. The results reported may not necessarily occur in all individuals. Self-treatment is not recommended for life-threatening conditions that require medical treatment under a doctor's care. For many of the conditions discussed, treatment with prescription or over the counter medication is also available. Consult your doctor, practitioner, and/or pharmacist for any health problem and before using any supplements or before making any changes in prescribed medications.

Our Author - Christine Morgan


Christine Morgan has been a freelance health and wellbeing journalist for almost 20 years, having written for numerous publications including the Daily Mirror, S Magazine, Top Sante, Healthy, Woman & Home, Zest, Allergy, Healthy Times and Pregnancy & Birth; she has also edited several titles such as Women’ Health, Shine’s Real Health & Beauty and All About Health.

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