Researchers uncover a neural signature of rumination in depression, highlighting potential targets for treatment
Rumination denotes the repetitive focus on negative thoughts and feelings that trigger depression. We know its psychological impact on our minds but we don’t know the underlying neural mechanisms that create the problem. A recent groundbreaking research has enlightened this complex phenomenon. As a result we can now find more options for effective treatments of depression.
A study in Psychiatry Research: Neuroimaging indicated structural brain differences linked to rumination. The study, “Structural alterations in a rumination-related network in patients with major depressive disorder,” was authored by Paul Z. Cheng, Hsin-Chien Lee, Timothy J. Lane, Tzu-Yu Hsu, and Niall W. Duncan. Researchers specifically identified changes in the precuneus. It is an area of the brain involved in brain functions such as memory, self focus and attention. Precuneus is highly connected to other networks of the brain. The findings from the study suggest that depression related rumination triggers from the interplay of broader neural networks. This has provided new insights into us on how our brain connectivity influences our negative thought patterns and how to make future therapeutic strategies to recover from depression.
The Neural Basis of Rumination
Rumination is a process of repetitive self focused negative thoughts about your problems or distress. It is strongly associated with the medial prefrontal cortex (mPFC) and anterior cingulate cortex (ACC). These regions of your brain work as the default mode network (DMN) and severely react when you go through depression. This hyperactivity perpetuates negative self referential thinking and makes it difficult for you to keep yourself away from maladaptive thought patterns.
Studies have also revealed increased functional connectivity between the dorsolateral prefrontal cortex (DLPFC) and the ACC. They reflect impaired cognitive control over your negative thoughts. This imbalance between cognitive control networks and the DMN triggers rumination and intensifies depressive symptoms.
This study compared multiple people with depression and found that rumination correlates with structural differences in the right precuneus. People with higher rumination levels showed reduced surface area in this region. After analyzing the functional connectivity of the precuneus it is found that it interacts with areas involved in executive function and memory. This clearly indicates that the brain’s network is interconnected in driving rumination.
Implications for Treatment
Rumination is definitely interconnected with a network level interaction and supports a broader theory on rumination. It reveals that depression symptoms may arise not from isolated regions in your brain but may be from the multiple brain regions that interact as networks.
The study author Niall W. Duncan, an associate professor at Taipei Medical University’s Institute of Mind, Brain and Consciousness added that their findings fit in with a general shift in how people think about how the brain works. He believes it is common to think that specific areas of the brain work on specific things. This is true but people must also consider the brain as a complete system where all of its regions need to work together.
He added – “What we see is that the rumination symptoms in the people we studied appear to be connected to one part of the brain that is well connected to lots of other ones. This might mean that the symptoms come from the system as a whole being put out of balance. That’s a tentative conclusion though that needs more investigation.”
By understanding these neural patterns experts are now trying to open new ways for targeted interventions. Treatments like Cognitive behavioral therapy (CBT) have shown great scope in modulating these networks. This primarily focuses on reducing hyperactivity in the mPFC and ACC. Practicing mindfulness may also help patients rewire their brain’s response to self referential thought and decrease rumination.
Mental health experts may suggest a few innovative options like Transcranial magnetic stimulation (TMS) and Deep brain stimulation (DBS). These therapies target specific neural circuits to reduce depressive symptoms. Experts believe stimulating the subgenual ACC is helpful in healing treatment resistant depression.
Mental health experts are targeting the specific brain regions that are causing rumination. They are trying to develop more effective interventions such as the following potential therapeutic approaches:
- Neurofeedback. This technique involves training individuals to regulate their brain activity so that they can reduce ruminative thoughts.
- Pharmacological Interventions. Prescribed drugs are given to patients as a part of treatment that can modulate the activity of the identified brain regions.
- Mindfulness Based Therapies. These therapies focus on present moment awareness and acceptance. These therapies can help you change your negative thought patterns as well as boost positivity in your thoughts.
The Road Ahead
This study highlights a significant progress in reducing rumination. Mental health experts are doing extensive research to understand the complex connection between neural activity, cognitive processes and human emotional states. Scientists and mental health experts are continuously trying new ways and exploring the neural mechanisms of rumination. Soon they will be able to develop more precise and personalized treatments for this disorder.
Duncan concluded – “It’s important to note that the people we were looking at were all older and had had depression for quite a long time. They were also almost all taking medication for their depression. These factors mean that what we found might not apply to people who have only recently developed depression. It may also be the case that what we observe is a consequence of the medication that people are taking, rather than of the depression directly. Finally, our participant group was relatively small so we’d definitely want to see the results replicated in other, larger, samples. This is the current main focus of the co-leader of the research, Dr Tsu-Yu Hsu. She is working on how rumination may be linked to differences in how people process mental contents that are related to themselves. This would make sense, since rumination is generally an issue where people have repetitive self-related thoughts.”
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