A neuroimaging study in Denmark showed that mindfulness-based cognitive therapy let to a decreased connectivity between the brain’s salience network and lingual gyrus during a depressive ruminative state. This change in connectivity mediated improvements in participants’ ability to sustain and control attention to body sensations. The study was published in Biological Psychiatry.
Depression is one of the most frequent psychiatric disorders. It is a leading cause of disability worldwide. With every depressive episode, the risk that the person will have another depressive episode in the future increases. After three depressive episodes, the risk that there will be another depressive episode rises to 80%.
Mindfulness-based cognitive therapy is one of the treatments used to reduce the risk that another depressive episode will occur in persons who already had multiple depressive episodes. This treatment method trains individuals to regulate their attention in ways that are adaptive and to be aware of their body states at the present moment. The idea behind the therapy is that these skills will help an individual recognize the onset of a so-called ruminative state and get out of it or avoid it altogether.
A ruminative state is a cognitive state in which a person is focused on negative content, past and present, resulting in emotional distress. This state perseveres and the person has difficulty getting out of it, particularly if he/she does not recognize that he/she is in a ruminative state. Ruminative states have been linked to the onset, maintenance and perpetuation of depressive symptoms.
The study author Anne Maj van der Velden and her colleagues wanted to examine brain activity mechanisms behind effective mindfulness-based cognitive therapy treatments of recurrent depression. They recruited 80 participants with recurrent major depressive disorder from general practices and local psychiatric units in the Central Jutland region of Denmark.
Participants were randomly divided into two groups in a 50:30 ratio. The larger group received an 8-week mindfulness-based cognitive therapy class in addition to their usual treatments. The other group only underwent their usual treatment (for depression) during this period.
At the start of the study and within 1 month after the end of the cognitive therapy classes, participants completed assessments of depressive symptoms (the Quick Inventory of Depressive Symptomatology-Self-Report), interoceptive awareness i.e., awareness of one’s bodily sensations (the Multidimensional Assessment of Interoceptive Awareness and the Experiences Questionnaire), mindfulness skills (the Five Factor Mindfulness Questionnaire, short version), and rumination (the Rumination Response scale).
Participants also underwent functional magnetic resonance imaging that included a structural scan and four separate functional connectivity scans. Each of these functional connectivity scans lasted for 5 minutes. Scans were done in several consecutive conditions – while the participant was resting, while he/she was guided through a mindfulness meditation state and while the participant was guided into a rumination state. The participation in the rumination condition was voluntary due to ethical reasons. Twenty participants decided not to participate in it and these participants had more pronounced depressive symptoms than the rest of the participants.
Results showed that the mindfulness-based cognitive therapy treatment reduced depressive symptoms compared to the usual treatment for depression. It also increased dispositional mindfulness skills, decentering and awareness of bodily sensations, of manifestations of one’s emotions in the body, the ability to listen to the body for insights and the ability to sustain and control attention to body sensations. There were no effects on rumination.
Researchers tested whether the mindfulness-based cognitive therapy treatment changed neural connectivity in the salience network and the default mode network of the brain. The default mode network is a large-scale brain network primarily composed of the dorsal medial prefrontal cortex, posterior cingulate cortex/precuneus and angular gyrus regions of the brain. It is most active when one is in a state of wakeful rest and not focused on the outside world. The salience network is anchored in the anterior insula and dorsal anterior cingulate cortex. Together with other interconnected networks of brain cells, it contributes to a variety of complex brain functions, including communication, social behavior, and self-awareness.
Results showed changes in the salience network connectivity with both the right lingual gyrus and the left lateral occipital cortex regions of the brain in the group that underwent the cognitive therapy treatment. When connectivity before and after the treatment were compared, results showed that the two groups did not differ before the first one underwent cognitive treatment. After the treatment, the group that underwent cognitive therapy showed reduced connectivity between the salience network and both regions of occipital cortex and the lingual gyrus of the brain.
“These findings showed that a clinically effective mindfulness intervention modulates neurocognitive functioning during depressive rumination and the ability to sustain attention to the body,” the study authors concluded.
The study provides a valuable contribution to the knowledge of the neural underpinnings of psychotherapeutic treatments. However, it should be noted that the study design lacked an active control group, so it remains unknown whether the observed effects were specific for the therapy procedure used in the cognitive therapy group or would any group work produce similar results. Additionally, researchers report not measuring the adherence to the treatment protocol during the mindfulness-based cognitive therapy treatments.
The study, “Mindfulness Training Changes Brain Dynamics During Depressive Rumination: A Randomized Controlled Trial”, was authored by Anne Maj van der Velden, Jacqueline Scholl, Else-Marie Elmholdt, Lone O. Fjorback, Catherine J. Harmer, Sara W. Lazar, Mia S. O’Toole, Jonathan Smallwood, Andreas Roepstorff, and Willem Kuyken.