By John M. de Castro, Ph.D.
“Skeptics, of course, may ask what good are a few brain changes if the psychological effects aren’t simultaneously being illustrated? Luckily, there’s good evidence for those as well, with studies reporting that meditation helps relieve our subjective levels of anxiety and depression, and improve attention, concentration, and overall psychological well-being.” – Alice Walton
In the last few decades, scientists have discovered that the brain is far more malleable than previously thought. Areas in the brain can change, either increase or decrease in size, connectivity, and activity in response to changes in our environment or the behaviors we engage in. This process is referred to as neuroplasticity. The nervous system is constantly changing and adapting to the environment. For example, the brain area that controls the right index finger has been found to be larger in blind subjects who use braille than in sighted individuals. Similarly, cab drivers in London who navigate the twisting streets of the city, have a larger hippocampus, which is involved in spatial navigation, than predefined route bus drivers. Hence experience changes size, activity, and connectivity of the brain. These changes in the brain are called neuroplasticity.
Over the last decade neuroscience has studied the effects of contemplative practices on the brain and has demonstrated that these practices produce neuroplastic changes in widespread areas. Indeed, mindfulness practices have been shown to not only alter how we think and feel but also to alter the nervous system, producing changes in the size, activity, and connectivity of specific structures and systems in the nervous system. Depression has been shown to also involve changes to the nervous system and is significantly improved by mindfulness practices. As a result of mindfulness practices’ ability to alter the brain and relieve depression, these practices have been incorporated into various psychotherapies for depression.
Mindfulness Based Cognitive Therapy (MBCT) was specifically developed to treat depression. It has been shown to be remarkably effective. Putting all these pieces together, it would seem likely that MBCT relieves depression by altering neural systems. In today’s Research News article “Multi-dimensional modulations of α and γ cortical dynamics following mindfulness-based cognitive therapy in Major Depressive Disorder”
Schoenberg and Speckens investigated changes in brain activity produced by MBCT using sophisticated techniques to explore the electrical activity that can be recorded from various regions of the scalp (Electroencephalogram, EEG). They compared patients with major depressive disorder who were randomly assigned to receive 8-weeks of group Mindfulness Based Cognitive Therapy (MBCT) or treatment as usual, waitlist control. They found that MBCT treatment produced clinically significant improvements in depressive symptoms, self-compassion, over identification with painful thoughts and feelings, and mindfulness. This is not surprising, and replicates the well-established finding that MBCT is highly effective in treating depression.
They recorded the EEG of both groups while they performed a Go/NoGo task. Performance on this task has been shown to be deficient in depressed patients and indicates deficient executive function. They found that MBCT significantly downregulated α and γ power in the electrical activity of the brain. This indicates that there was and increase the excitability of the cerebral cortex. This is generally associated with greater positive mood and decreased negative emotions. This suggests that MBCT may relive depression by its effects on the neural systems underlying the depressed mood.
They also found an enhancement of the α-desynchronisation occurring in response to the Go/NoGo task when negative material was presented, but decreased α-desynchronisation when positive material was presented. This suggests that MBCT activates the neural networks underlying positive emotion. These are the systems that are usually relatively inactive in depression. This again suggests that MBCT may relieve depression by enhancing the activity of neural systems responsible for positive mood, thus working in opposition to the negative mood so characteristic of depression.
Finally, they found that MBCT increased intra-hemispheric α-coherence of the fronto-parietal circuit. This coherence has been shown to be related to improved attention and reduced mind wandering. In depression, mind wandering is highly related to rumination which tends to reinforce and support the depressed state. This suggests that MBCT may relive depression by enhancing the coherence of neural systems responsible for attention, thus inhibiting the mind wandering and rumination so characteristic of depression.
Hence the present study found evidence for changed electrical dynamics in the cortex of depressed patients following Mindfulness Based Cognitive Therapy (MBCT). The changes that were observed reflect changed processing of emotional information and attention, such that positive mood was enhanced, negative mood was reduced, and mind wandering and rumination decreased. All of these processes tend to counteract depression and may at least in part be responsible for the effectiveness of MBCT in treating depression.
So, change brain activity in depression with mindfulness.
“Being in the present moment, accepting what is, without wanting to change or interpret it, will greatly enhance emotional well-being, leading to healthier thinking patterns that will touch and better every other aspects of your life.” – Jonathan Banks
CMCS – Center for Mindfulness and Contemplative Studies