Some say that grief is the price we pay for love. For many, it rings true. Whether it’s a spouse, family member, friend or beloved pet, most of us will experience loss within our lifetime. In 2023, more than 180,000 people died in Australia alone, and according to the University of Cambridge, it’s estimated that for every death, nine people are affected by bereavement.
While no two people grieve in exactly the same way, there are chemical changes that take place in the grieving brain that affect us all. These changes can leave us feeling hopeless, anxious and fatigued. They can also cause challenges with cognitive functions such as memory, concentration and decision-making. But by better understanding how our brain is rewired by grief, we can take steps towards healthy healing and find ways to live with loss.
Survival mode, activated
Sometimes a loss happens without warning, leaving loved ones in shock and disbelief. For others, the journey can be long, perhaps filled with hospital visits, bad news and the physical or cognitive decline of their loved one.
Dr Lisa M Shulman, MD, is a professor of neurology at the University of Maryland and author of Before and After Loss: A Neurologist’s Perspective on Loss, Grief, and our Brain. According to Shulman, regardless of the timeframe or circumstances, grief and loss are forms of emotional trauma. This triggers our brain to default to survival mode and to psychological defence mechanisms, locking our brain into a stress response.
Stress — like that experienced through loss — activates neuroplasticity, the remodelling of the brain’s neural connections based on experience. In other words, our brain “rewires” itself during the grief process.
“The brain is agnostic to the type of emotional trauma and has a primitive hard-wired response to traumatic experience,” says Shulman. “This hard-wired response — for good reason — is designed to protect us and ensure our survival in the worst of times. It allows us to function, even under dire circumstances.”
This survival response activates the body’s sympathetic nervous system, engaging the brain’s “fight or flight” mechanism. Daily reminders of loss can repeatedly trigger this response, reinforcing it. Over time, this can lead to chronic stress, which can negatively impact health by increasing blood pressure and heart rate, and release stress hormones like adrenaline.
“The loss of a loved one is experienced over periods of days, weeks, months, years, resulting in an accumulation of traumatic experiences,” Shulman explains. “Learning of a new diagnosis, the shocking news of a fatal accident, failed medical treatments, are persistent reminders of loss in our daily life.
“Each and every experience reactivates these primitive responses of fight or flight, relentlessly strengthening neural connections in the [brain’s] primitive fear centre and weakening connections to the advanced brain regions [responsible for] controlling sound judgement.”
According to Shulman, this rewiring is unavoidable and can result in anxiety, sleep disturbance, disturbing dreams, intrusive thoughts such as flashbacks and a range of psychological defensive mechanisms like repression, denial and dissociation.
Grief brain
Anyone who has lost a loved one probably knows the feeling of “brain fog” or “grief brain” that comes alongside it. It’s that sense of walking into a room and immediately forgetting why. The sense of reaching the bottom of a page and realising you haven’t retained anything you’ve just read. It’s struggling to make simple decisions like what to wear or what to eat for breakfast.
Lucy Archinal-Hudson is a Canberra-based clinical psychologist and the former clinical director at Feel the Magic, an Australian grief charity that supports children and families after the death of a parent. “The term ‘grief brain’ is used to describe the cognitive impacts of grief due to the fatigue and depleted mental resources experienced when the mind is under acute stress or focused on survival, including activation of the amygdala [the brain’s emotional processing centre, which regulates perception of threat] and changes in stress hormone levels,” explains Archinal-Hudson.
“Acute grief [experienced immediately or shortly after loss] can result in difficulty concentrating, difficulty making decisions, slower processing speed, being more distractible, experiencing memory problems and forgetfulness, and difficulty engaging the logical areas of our brain.”
According to Archinal-Hudson, the impacts of “grief brain” go beyond cognitive skills, they can have a knock-on effect on other elements of our health and wellbeing. Physical effects can include headaches, changes in appetite, muscle tension and fatigue. Emotional impacts include irritability, sadness, numbness, anger, guilt and regret.
“These impacts can often compound and become a vicious cycle,” says Archinal-Hudson. “For example, low mood can result in withdrawing from friends or activities, which in turn increases feelings of loneliness, which in turn results in low mood. Similarly, difficulties with attention can result in reduced work capacity or performance, which can lower self-esteem.”
Research also echoes the idea that our physical health is impacted by grief. According to research released in 2024 and conducted by Columbia University Mailman School of Public Health and the Butler Columbia Aging Center in the US, people who suffered a loss of a close family member such as a partner, parent, child or sibling appeared to have an olde