On Friday I attended the Eastern Division of the Royal College of Psychiatrists Autumn Conference on the ‘Intersection between physical and mental health.’
We often think of physical health and mental health as 2 separate aspects of our wellbeing. You may visit a doctor when you have a physical complaint or anxiety and depression. The relationship between physical and mental health is much closer than you imagine. Our bodies and minds are intrinsically connected, and looking after one can have a significant impact on the other.
The importance of physical health in maintaining good mental wellbeing. Exercise, nutrition, sleep and the management of physical health conditions all play an important role in how we think, feel and function.
Understanding this connection can help us take a more holistic approach to health and recognise that small changes to our physical wellbeing can have meaningful psychological benefits.
The brain is part of the body, and its functioning is influenced by a complex interaction of biological, psychological and environmental factors.
Physical health can influence mental health through several mechanisms, including hormonal regulation, inflammation, immune system activity, neurotransmitter function and the body’s stress response.
For example, prolonged physical illness, chronic pain or inflammation can contribute to fatigue, irritability, low mood and difficulties with concentration. Equally, psychological distress can affect physical health, contributing to muscle tension, headaches, digestive problems, disrupted sleep and changes in appetite.
This relationship works in both directions. Poor mental health can make it harder to maintain healthy physical habits, while poor physical health can increase vulnerability to mental health difficulties. Recognising this two-way relationship is essential to providing effective and comprehensive healthcare.
Physical activity is one of the most accessible and well-established ways of supporting psychological wellbeing. Regular exercise has been associated with improvements in mood, reduced anxiety and depressive symptoms, better sleep and improved cognitive functioning. Exercise can support mood through several related processes. It influences serotonin, dopamine and noradrenaline, brain chemicals involved in mood regulation, and stimulates the release of endorphins, which are associated with positive feelings and reduced perception of pain. Physical activity can also help regulate the body’s stress response and reduce physiological tension, including the effects associated with cortisol, adrenaline and the fight-or-flight response. It is associated with increased production of brain-derived neurotrophic factor (BDNF), a protein involved in the growth and survival of neurons and the connections between them. Aerobic exercise stimulates BDNF production, supporting new neurons and stronger neural connections, particularly in the hippocampus, a region involved in memory and emotional regulation that can be affected by chronic stress or depression. Alongside these biological effects, achieving physical activity goals can build confidence and provide a sense of accomplishment.
Exercise can also provide opportunities for social interaction, particularly when undertaken in groups, through team sports or walking with friends. Importantly, exercise does not have to involve intensive gym sessions or competitive sport. Walking, cycling, swimming, dancing, gardening and other everyday activities can all contribute to improved physical and psychological health. The most effective form of exercise is often the one that you enjoy and can sustain.
What we eat influences not only our physical health but also the way our brain’s function. The brain requires a consistent supply of nutrients to support neurotransmitter production, energy metabolism and normal cognitive functioning. A balanced diet containing vegetables, fruit, wholegrains, protein, healthy fats and adequate fibre supports these processes.
There is growing interest in the relationship between diet, the gut microbiome and mental health. The gut and brain communicate through several pathways, including the nervous system, immune system and hormonal signalling. This is often referred to as the gut-brain axis. 90% to 95% of the body’s serotonin is produced in the gastrointestinal tract, not the brain. Your gut microbiome communicates directly with your central nervous system via the vagus nerve, meaning what you eat dictates how you feel.
The gut microbiome, which consists of trillions of microorganisms living within the digestive system, may influence inflammation, stress responses and aspects of brain function. Diets high in ultra-processed foods, refined sugars, and trans fats trigger systemic inflammation. Chronic inflammation has been strongly linked to higher rates of depression and brain fog.
Research on dietary quality offers one way to understand the relationship between nutrition and mental wellbeing. Observational studies have associated a Mediterranean-style diet rich in vegetables, fruit, legumes, nuts, wholegrains, olive oil and fish with better mental health outcomes. Some intervention studies also suggest that improving dietary quality may help reduce depressive symptoms. Within this broader picture, omega-3 fatty acids, found in fatty fish, walnuts and flaxseeds, feature alongside complex carbohydrates and fermented foods in discussions of gut diversity and cognitive wellbeing.
Maintaining regular eating patterns and avoiding excessive reliance on highly processed foods can also help support energy levels and concentration. Skipping meals or relying on simple carbohydrates causes sharp blood sugar spikes followed by crashes. Those crashes trigger a release of adrenaline and cortisol, mimicking the physical symptoms of an anxiety attack (shakiness, irritability, racing heart).
Food should not be viewed as a replacement for appropriate mental health treatment, but nutrition is an important part of a broader approach to wellbeing. Roughly 90% to 95% of the body’s serotonin is produced in the gastrointestinal tract, not the brain. Your gut microbiome communicates directly with your central nervous system via the vagus nerve, meaning what you eat dictates how you feel.
Sleep is fundamental to both physical and mental health. During sleep, the brain undertakes important restorative processes, consolidates memories and regulates emotional responses. Poor sleep can have a considerable impact on mood, concentration, decision-making and emotional resilience. Even relatively short periods of sleep deprivation can increase irritability, anxiety and sensitivity to stress.
There is also a strong relationship between sleep disturbances and psychiatric conditions. Establishing a consistent sleep routine, limiting caffeine later in the day, reducing screen exposure before bedtime and creating a comfortable sleeping environment can all help improve sleep quality. Persistent sleep problems deserve attention rather than being dismissed as an inevitable consequence of a busy lifestyle.
It is nearly impossible to maintain emotional equilibrium on a chronic sleep deficit. During deep sleep and REM (Rapid Eye Movement) cycles, the brain processes emotional memories, clears out metabolic waste, and resets its threat-detection centre. When you are sleep-deprived, the amygdala becomes hyper-reactive, while its connection to the prefrontal cortex weakens. Then minor inconveniences feel like catastrophes, patience evaporates, and anxiety increases.
Living with a long-term physical health condition can place considerable psychological demands on an individual. Conditions such as diabetes, cardiovascular disease, chronic respiratory illness, autoimmune disorders and chronic pain can affect independence, employment, relationships and quality of life. The uncertainty associated with a diagnosis, the burden of ongoing treatment and the limitations imposed by symptoms can contribute to anxiety and depression.
There is also evidence of a bidirectional relationship between certain physical and psychiatric conditions. For example, people with diabetes have an increased likelihood of experiencing depression, while depression can make diabetes self-management more difficult. Chronic pain is another important example. Persistent pain can affect sleep, mobility, social engagement and mood, potentially creating a cycle in which physical discomfort and psychological distress reinforce one another.
It is therefore important that healthcare professionals consider psychological wellbeing when managing physical illness. Equally, people receiving treatment for mental health conditions should have their physical health needs recognised and addressed.
Our lifestyle choices can have a significant influence on both physical and mental health. Alcohol is sometimes used as a way of managing stress, anxiety or low mood. Although it may initially produce feelings of relaxation, alcohol can disrupt sleep, worsen anxiety and contribute to depressive symptoms. Regular excessive consumption also increases the risk of a range of physical health conditions.
Smoking is associated with substantial physical health risks. Although nicotine can temporarily alter mood and concentration, dependence can create cycles of withdrawal and relief that may reinforce anxiety and stress.
Reducing alcohol consumption, stopping smoking and avoiding recreational drugs can all contribute to better long-term physical and psychological wellbeing. These changes are not always easy, particularly when substances have become a way of coping with emotional distress.
Maintaining physical health becomes increasingly important as we get older. Regular physical activity can help preserve muscle strength, balance, mobility and cardiovascular health. These benefits support independence and reduce the risk of falls and disability. There is also growing evidence that physical activity is associated with better cognitive health and a reduced risk of cognitive decline.
Conditions affecting cardiovascular health, including high blood pressure, diabetes and high cholesterol, are also relevant to brain health. Managing these conditions can help reduce the risk of vascular damage and contribute to protecting cognitive function. Looking after our physical health throughout life may therefore have benefits that extend well beyond the immediate effects on mood and energy.
Improving physical health does not necessarily require dramatic lifestyle changes. Small, consistent steps can make a meaningful difference. Aim to incorporate regular physical activity into your daily routine. Even a short walk can be beneficial. Choose a varied, balanced diet and try to establish regular eating patterns. Maintain a consistent bedtime and waking time wherever possible. Natural light, fresh air and contact with nature can support mood and wellbeing. Social activities, group exercise and spending time with others can support emotional health. Be mindful of how alcohol affects your sleep, mood and physical health. Monitor relevant physical health indicators and seek medical advice about persistent symptoms. Set achievable goals and focus on consistency rather than perfection.
It is important to recognise that physical activity and lifestyle changes should be adapted to individual circumstances, particularly for people living with physical disabilities or long-term health conditions.
The traditional separation of physical and mental healthcare does not always reflect the reality of how people experience illness. Mental health difficulties can have physical consequences, and physical illness can have profound psychological effects.
A holistic approach recognises that good healthcare should consider the whole person rather than focusing exclusively on individual symptoms or diagnoses.
There should be greater integration between physical and mental healthcare, with professionals recognising the importance of both. Physical and mental health are inseparable. The way we move, eat, sleep and manage our physical health can influence our emotional wellbeing, cognitive functioning and resilience.
We should not underestimate the psychological benefits of looking after our bodies. Regular exercise, a balanced diet, good-quality sleep and appropriate management of physical health conditions can all contribute to better mental health.
Mental illness is complex, and people experiencing significant psychological difficulties may need professional assessment and evidence-based treatment. Lifestyle changes can form part of a broader approach to wellbeing, but they should not be presented to prevent or treat every mental health condition.
Ultimately, looking after our physical health is not simply about preventing disease or improving fitness. It is an investment in our mental wellbeing, quality of life and ability to manage the challenges of everyday life.