Can our brain be treated separately from our body?
The current piece is written by Dr Naghmeh Nikkheslat, who together with Professor Paola Dazzan, leads the Therapeutic Approaches of Mind-Body Interface Module as part of the newly established MSc in Psychology and Neuroscience of Mind-Body Interface at King's College London. As part of a series of ITM pieces on our new MSc, this blog aims to take you through the question of whether our brain can be treated separately from our body. ITM has already published four pieces: two provided by the MSc lead, Dr Alessandra Borsini, on how this knowledge can support the clinical and academic career of students, and on the many mechanisms connecting the brain, the mind, and the body; the third by the co-lead of the Neuroscience Module, Professor Carmine Pariante on the role of blood and hormones in the mind and body interface; and the fourth by Dr Giulia Lombardo, the co-lead of the Psychology Module, on integrating mental and physical health as a complete picture.
As a senior research scientist at the Institute of Psychiatry, Psychology & Neuroscience (IoPPN) at King's College London, I am co-leading the ‘Therapeutic Approached to Mind-Body Interface’ module on the new MSc. This module aims to provide a comprehensive understanding of the range, availability, and effectiveness of pharmacological, psychological, behavioural, and nutritional interventions in the treatment of mental health problems where there is comorbidity with physical conditions and/or evidence of the involvement of bodily impairments including immune system dysregulation, inflammation, and stress related effects on the brain.
For a long time, it was believed that our brain is enclosed by what is called a “blood brain barrier”, to protect it from any harmful substances entering from the rest of the body. However more recently, this view has been challenged by scientists who investigated the passage of tiny bodily substances across the barrier and found them to be present in the brain. This perfectly symbolyses the permeability and cross-communication between the brain and the body that is occurring in a variety of different ways.
Some people may still see the brain as a separate entity from the body, especially when it comes to the concept of ‘mind’, which is the conscious product of the brain’s activity, and refers to our ability to think, feel, and perform. However, we now know that our body and brain are tightly connected, and both can influence our mind and mental well-being. For example, individuals who suffer from depression, which is generally known as a condition affecting our ability to feel happy, often complain of physical symptoms, such as pain or extreme tiredness.
When investigating both the brain and body of depressed patients, there is evidence of inappropriate activation of the immune system and inflammation in some individuals. The immune system consists of various types of immune cells, which are developed to defend our body against infections caused by viruses and bacteria. Upon activation of the immune system in response to such foreign invaders, inflammatory substances, called ‘cytokines’, are produced to further help fight the infection, and this is how the body presents an elevated inflammatory response or ‘inflammation’.
Immune and inflammatory responses are regulated by our stress system, which is governed by parts of the brain and leads to the production of the ‘stress hormone’ cortisol in the body. Cortisol is not only produced in response to stress but also as an anti-inflammatory, meaning that it can bring the activation of the immune and inflammatory responses back to normal. This is because too much inflammation can be damaging to the body. Unfortunately, this regulatory system can be dysfunctional in some patients, so cortisol becomes less effective in bringing the inflammation down.
The production of an inflammatory response can be triggered by stress because our brain perceives and responds to psychological threats, such as stress, in the same way as it does to physical threats, such as infections, and tries to protect us from these various stressful environmental factors throughout life. For example, experiencing childhood adversities and traumatic events can lead to activation of our immune and inflammatory responses, making us vulnerable to the development of depression later in life.
Excessive levels of cytokines in the body for a long period of time can potentially affect the brain and its structure and function. One of the mechanisms through which inflammation can affect the brain is by crossing the blood brain barrier. The presence of inflammation in the brain is known as ‘neuroinflammation’. This is an important example of the mind-body interface, as depression is linked to inflammation both in the body and the brain.
Inflammation in the body can lead to various physiological conditions such as heart disease and chronic fatigue syndrome. Inflammation in the brain can lead to various psychological disorders such as depression and anxiety. So, inflammation may play a role in the comorbidity of these conditions, that is, the observation that patients with one of these disorders are at greater risk of developing another one at the same time. All these relationships are often bidirectional.
From what has been discussed so far regarding inappropriate activation of the immune system and inflammatory responses that can impact both the body and the brain, can we even think that our brain can be treated separately from our body?
Indeed, when considering therapeutic interventions for mental health problems, it is crucial to understand what is happening in the body and to address the mechanisms responsible. Considering depression again as an example, this is particularly important since not all the patients with depression respond to available antidepressants. When scientists investigated this lack of response, they discovered that individuals with high inflammation were indeed the ones less responsive to the effects of antidepressants. Interestingly, using a combination of anti-inflammatory and antidepressant medications may improve the depressive symptoms in these patients.
Additionally, there is evidence that the effective antidepressants are those that alongside balancing the brain chemicals, also have an effect in resolving the immune and inflammatory systems dysregulation. Investigating the mechanism of action of antidepressants is an important line of research, since it provides insights for developing new effective antidepressant medications.
Reducing inflammation in relation to overall improvement in physical and mental wellbeing is also studied through the benefits that a healthy diet, exercise, mindfulness, and psychological interventions can bring for our mind and body.
The ultimate goal of these studies is to develop personalised treatments that specifically target the mechanisms responsible, and which play key roles in connecting the body and the brain.
