Exercise and mental health
Alright let's talk about physical activity, the brain and your mood. In this article I will explain how physical activity has been studied and shown to produce positive changes in the neurobiology ( the physical changes to the brain tissue) and neurochemistry ( the chemical changes ) of the brain. I will also talk about how these changes have positive effects in reducing symptoms of depression and anxiety.
Before I get into it, let’s review some basic neurochemistry and neurobiology.
Endorphins: can be neurotransmitters or hormones, known as our endogenous opioids. They alleviate pain and produce feelings of euphoria. Endorphins are released during exercise, sex and painful experiences (sprained ankle). This is where that pleasure/pain can produce the same response ( ok that's for another post). Endorphins can reduce physical pain, increase pleasure, reduce stress, depression and even anxiety.
Dopamine: responsible for our ability to start movement, memory, reward and motivation. Dysfunction of the dopamine system can be associated with Depression and Parkinson Disease
Serotonin: responsible for the regulation of mood, libido, appetite and body temperature. Lack of serotonin plays a role in depression, anxiety and bi polar disorder.
Glutamate: our main excitatory neurotransmitter; related to memory, cognition and mood regulation
Gaba: primary inhibitory neurotransmitter; inhibits neuronal excitability and inhibits nerve transmission. The ‘stop’ to neuronal communication.
Brain Derived Neurotrophic Factors: stimulates the growth of certain neurons.
Hippocampus: located in the temporal lobe. Responsible for learning and memory and spatial navigation. Part of the limbic system which is related to emotion, behavior, long term memory and smell.
Amygdala: responsible for the control and perception of emotions such as fear, anger and sadness. Located in the temporal lobe and are part of the limbic system.
Frontal Cortex: associated with personality, mood, ability to make choices and reasoning. Think of it as your main area for thoughts and behavior.
Hopefully this brief neuroanatomy and neurochemistry helps you understand this article more clearly. I'll start off by stating that most studies done on the effects of physical activity and the neurochemical and neurobiological changes have been done on animals. However more studies are starting to be done on humans and some of the articles and studies I reviewed were directly related to human studies. Below I will outline what I discovered in my readings.
There is a long list of positive effects that exercise has on the brain; here is a little list:
Endorphin release causing feelings of euphoria
Physiological changes to the prefrontal cortex
Changes to malformed white matter in those with certain mood disorders
Improved decision making
Improved overall cognition
Decreased depression, anxiety, anger and confusion
Improved memory
Protects again dysfunctional activation of the amygdala
An increase in dopamine and serotonin
Increased brain plasticity
Increased levels of Brain Derived Neurotrophic factors
Anti inflammatory/regulates the immune system
Lower levels of cortisol at rest
Ok so what does this mean, let's take a look at the physical changes that happen first. Studies show that specific areas of the brain such as the prefrontal cortex, can change in a positive way. What this means is our ability to make decisions, our cognition, mood and what you may call personality all improve due to these positive changes. A malformation in white matter is seen in individuals with depression and anxiety. This malformation causes a lack of connectivity between neurons. FMRI scans have shown that exercise increases the density of white matter which leads to stronger, faster and better connections of neurons.
Anxiety and chronic stress can be related to a dysfunction within the amygdala which is known for its role in fear and memory. Exercise has shown great improvements in protecting against the dysfunctional activation of amygdala. This means that adhering to an exercise program can greatly decrease symptoms of anxiety. The increase of endorphins such as dopamine and serotonin give the euphoric feeling we experience post workout. It has been shown that with consistent exercise, we can also change the neurochemistry of the brain; allowing for more Brain derived neurotrophic factors to be released, increases neuronal connections and plasticity. Physical activity is also known to reduce inflammation which is a main cause of mood disorders such as depression and anxiety. Along with a decrease in inflammation we also get a more regulated immune system. Exercise mimics high stress situations and panic; such as increase in heart rate and blood pressure, sweating and shortness of breath. Individuals who suffer from panic disorders can improve their panic symptoms through exercise as a way of exposure therapy.
In conclusion exercise is a wonderful tool to use with therapy and or mediction to reduce the symptoms of certain mood disorders and improve your overall brain health. It is not an alternative however, so please, if you are in need of help, reach out to your doctor for a recommendation to a good therapist and if needed medication