Many people experience stress, anxiety or depression through their lives. Summary  data from the National Study of Mental Health and Wellbeing (2023) for the period  2020-2022 (www.abs.gov.au) reveals that over two in five Australians aged 16-85 years  had experienced a mental disorder at some time in their life. What a high number that  is! While it can feel like you are alone in your mental health challenges, there is a good  chance that you know many other people who are also struggling. Mental health  affects us in many ways but today we will be looking at the impact stress, anxiety and  depression have on your nervous system.

Your nervous system is central to how you experience stress, anxiety, and depression. As you may have already experienced, these conditions affect both your mind and body, stirring up a range of physical reactions that can leave you feeling out of control or more worried. Understanding how your nervous system reacts can help you take steps toward healing and protecting your physical and mental health. While everyone’s journey with stress, anxiety, and depression is deeply personal, there’s a shared experience that many of us can relate to. If you’ve ever found yourself feeling like your thoughts are racing, your heart is pounding, or you’re caught in a cycle of worry that’s hard to shake, you’re not alone. The way our bodies react to mental health challenges is often remarkably similar, and that’s not by chance. Our nervous systems, designed to protect us, can end up being on high alert for extended periods, especially when we’re under stress. This isn’t just something a few people go through—it’s a reality for many of us. And here’s the thing: recognising this shared response can be a turning point. It can empower you to take action, explore ways to protect your nervous system, and find pathways toward healing and balance.

The Stress Response: Your Body’s Alarm System 

Stress hormones are chemicals released by the body in response to stress, helping to trigger the “ fight-or-flight ” response. The main stress hormones include cortisol and catecholamines (such as adrenaline and norepinephrine). These hormones prepare the body to deal with threats by increasing heart rate, energy levels, and focus. In the short term, this is helpful − it helps you focus attention to dealing with challenges and improving safety.  

However, in the long-term, chronic stress can cause a sustained increase in cortisol and other stress hormones , disrupting normal bodily functions. Symptoms of elevated stress hormones  include weight gain, muscle weakness, heart disease, and sleep problems. Chronic stress also  increases the risk of mental health issues and unhealthy coping behaviours. 

Anxiety: When Your Nervous System Stays on Edge 

Anxiety is different from stress in that it’s often more persistent. While stress is typically linked to a specific event or situation, anxiety can feel like an ongoing sense of worry, fear, or dread, often about things that might happen in the future. When you experience anxiety, the amygdala —the part of your brain that processes emotions like fear—becomes overactive. This triggers the release of stress hormones − cortisol, adrenaline and norepinephrine − putting your body in a heightened state of alert. 

Your heart might race, your breathing may become shallow, and your muscles may tense up, even  when there’s no immediate threat. In addition to physical symptoms, anxiety can also affect your  thoughts, making it harder to concentrate or calm down. Over time, chronic anxiety can weaken  your body’s ability to relax and recover, leading to a cycle of heightened nervous system activity  that can feel exhausting and overwhelming. It can also begin to impact your physical health. 

Depression: A Slower, More Subtle Shift in Your Nervous System 

Depression is a bit different—it’s not just about feeling sad. It’s a  complex condition that involves changes in the brain and nervous system, often leading to a sense of emotional numbness or deep fatigue. In depression, certain neurotransmitters —such as serotonin, dopamine, and norepinephrine − become out of balance. These chemicals play key roles in regulating mood, energy, and motivation, so when they’re not functioning properly, it can feel like you’re stuck in a fog. 

Rather than being in a constant state of heightened alertness (as with anxiety), people with  depression may experience the opposite: a shutdown of the nervous system. The  parasympathetic nervous system (PNS), which is responsible for calming the body, may dominate,  leading to feelings of exhaustion, apathy, and a lack of motivation. It’s like your body is in a  constant state of rest and recovery, but without the energy or enthusiasm to engage in life.

How Stress, Anxiety, and Depression Overlap 

It’s important to understand that stress, anxiety, and depression often overlap, and one can trigger  or worsen the others. Chronic stress can lead to anxiety, and long-term anxiety can increase the  risk of depression. Your nervous system may get caught in a cycle, with each condition feeding  into the next, making it harder to break free from the emotional and physical toll. 

By recognising the profound effects that stress, anxiety, and depression have on the nervous  system, individuals can take proactive steps to manage these conditions and support their mental  and physical health. 

Taking Proactive Action: Helping Your Nervous System Heal 

Recognising how your nervous system responds to stress, anxiety, and depression is the first step  in managing these challenges and taking proactive steps toward recovery. There are many  approaches that can help restore balance to your nervous system and support your overall well being. Mindfulness practices, breathing exercises, lifestyle changes, and physical activities like  yoga can help activate your body’s relaxation response, switching on the parasympathetic  nervous system to counterbalance the effects of stress and anxiety and to help your body and  mind recover, restoring peace and balance to your life.  

If you struggle to manage the activation with these self-help oriented approaches, there are  several therapeutic approaches that can be tailored to your unique needs. Techniques like  Acceptance and Commitment Therapy (ACT) helps manage activation of the nervous system by  teaching you to accept uncomfortable feelings and bodily sensations without judgment, while  encouraging you to commit to actions aligned with your values, which can reduce the power of  stress responses and increase psychological flexibility. Similarly, mindfulness meditation help  calm the body and mind by fostering awareness and presence, which can reduce the physical  symptoms of stress.  

Breath-work practices, such as deep diaphragmatic breathing or the 4-7-8 technique, promote  relaxation by directly influencing the nervous system to shift from a “fight or flight” state to a more  balanced, relaxed state. Somatic therapy involves focusing on the body’s sensations to help  release stored tension and trauma, enabling you to reconnect with your body’s natural ability to  self-regulate. Cognitive Behavioural Therapy (CBT) and Eye Movement Desensitisation and  Reprocessing (EMDR) can also be effective in addressing the thoughts and emotions that trigger  nervous system activation, helping to reframe responses to stress and trauma. 

By exploring these approaches, you can discover what works best for you in reducing overwhelm  and creating a sense of safety and stability in your body. 

Remember, you don’t have to go through this alone—help is available, and  healing is possible.