Stress: What happens in the brain?

A recent YouGov survey reports that 1 in 5 people feel unable to manage stress at work. The research shows that lack of mental health awareness and access to support services are significant aspects of the problem.

Stress is an important communication between mind and body which directs attention and response to threats in our environment. This happens at a subconscious level. The amygdala (a small almond-shaped region of the brain) acts as an alarm system, sending out a distress signal to other brain regions when a threat is perceived. The brain’s hypothalamus responds and hits the accelerator, metaphorically speaking. It triggers an increase in adrenaline which we need for speed, strength, and alertness; and of cortisol, which we need to sustain this physiological state for the duration of the threat. This ‘fight-flight-freeze’ response is vital in protecting us from physical danger.

This stress response is an asset in unpredictable environments and cannot be eliminated entirely. Too little stress would lead to apathy and inability to deal with immediate problems. In the short term, stress boosts motivation and enhances our ability to deal with urgent tasks. When our body is in threat-response mode, however, other important bodily functions co-ordinated by the brain are de-prioritised such as digestion and cell repair. Therefore prolonged activation of the stress response can impair the immune system and have a negative impact on our physical and mental health.

We have had many additional stressors recently such as health concerns, caring responsibilities, job insecurity, financial worries and social isolation. Another stressor is our own thinking. An accidental scientific discovery in 2007 showed that our brains are more active in quiet moments than when we are involved in goal-oriented activity. This ‘default mode network’ our brain is involved in inner-rehearsal (like daydreaming) which can be creative and productive. However, when we are stressed or anxious our imagination can go into overdrive, thinking of all the things that might go wrong.

Neuroscientific research studies show that physical and psychological threats are processed in a similar way and prolonged physical or psychological stress produces functional and anatomical changes in the brain. When chronically stressed the amygdala becomes enlarged and we literally devote more brain space to threat perception and response. The communications machinery of the amygdala ramps up so that this alarm system becomes more sensitive which can create a vicious cycle. The good news is that these changes to the brain are largely reversible.

Sleep provides a natural mechanism for alleviating stress. Neuroscientist Matthew Walker describes sleep as overnight therapy with good reason. During the REM phase of sleep stress chemicals drop away and the brain can process and recalibrate our emotional responses to the stressors we experience each day. However, during periods of prolonged stress our sleep patterns are disrupted, and we are unable to process everything in our ‘inbox’. This can reduce our stress tolerance threshold.

Therapeutic support can help in developing resilience to stressors. Dr Olivia Remes is Programme Director of Leading Mental Health in the Workplace at the University of Cambridge. Her research explores how people living in severe stress-provoking situations respond in different ways. A key factor which distinguishes adverse and resilient responses is the range of coping strategies and sense of coherence people have and social support is a big factor in this.

It is important to be aware of how stress affects the brain and body and of the support that is available. There are many good online resources and support services available. Mental Health UK and Anxiety UK are good points of access to these. Employers are recognising the importance of preventative action to avoid the harmful effects of stress through new ways of working and proactive employee support. Employee assistance programmes are improving access to talking therapies such as hypnotherapy which help clients better understand and address the contributors to stress.

Contact me if you would like to know more about how hypnotherapy can alleviate the effects of stress and expand your mental health toolkit.

Catherine O’Connell PhD, Solution Focused Hypnotherapist