Decades of enhancing neural connections can make the adult brain stubbornly resistant to rapid changes. If our brain's structure traps us in cycles of dark moods and thoughts, it can be very difficult to break free from disorders like chronic depression. According to new research, some patients suffering from Major Depressive Disorder (MDD) can rewire their brains within weeks with the proper treatment.
Antidepressants, behavioral therapy, and electroconvulsive therapy do not work for everyone with MDD, but scientists in Germany claim that these treatments have the potential to change brain structures. Individuals with MDD often struggle with regulating negative emotions and their physiological responses to stress. Under such harsh conditions, enjoying even the most pleasurable activities in life can be exhausting.
In the past, brain imaging studies have found that severe depression is associated with changes in the volume of gray matter (made up of neuronal cell bodies) and white matter (comprising nerve fibers). It is also linked to increased activity in the amygdala, which affects emotional experiences, and shrinkage in the hippocampus, which plays a crucial role in long-term learning and memory, as well as shrinkage in the basal ganglia, which helps process emotions. On the other hand, treatment-resistant MDD is characterized by changes in the basal ganglia and the lobe that processes sensory information.
If there is indeed a strong link between the structure of the human brain and depression function, it may seriously aid in improving diagnosis and treatment. However, researchers today disagree on whether this link is stable or strong enough to rely on. Researchers in Germany believe it is. Their new study was presented at the 35th Annual European College of Neuropsychopharmacology in Vienna.
The findings suggest that some structural brain characteristics present in patients with major depression were alleviated when antidepressant treatment was successful. Before receiving depression treatment, the brains of 109 patients with mood disorders were examined using MRI. The patients were later treated with either electroconvulsive therapy, psychotherapy, antidepressant medications, or a combination of all treatments. After six weeks from the initial MRI scan, the patients' brains were re-examined. The "before and after" results were compared with the brains of 55 healthy participants.
In the end, researchers found that patients showing the greatest improvement in symptoms also exhibited the most structural changes in the brain. After six weeks, connectivity between neurons in certain brain areas increased, and these effects were independent of the choice of treatment. Psychologist Jonathan Ripple from Frankfurt University stated, "We were surprised by the speed of the response. We do not have an explanation for how these changes occur or why they should happen in such different forms of treatment."
Controlled trials have shown that electroconvulsive therapy, cognitive behavioral therapy, and antidepressants can significantly improve depression symptoms, but it is difficult to link this improvement to structural changes in the brain. Electroconvulsive therapy appears to be the most effective and rapid for the group, although it comes with more side effects, and scientists are still trying to figure out the most successful regimen.
Electroconvulsive therapy works by passing an electric current through the patient's brain while under general anesthesia, and in studies on mice, it seems to improve communication between neurons in certain brain regions. In fact, researchers from Johns Hopkins University recently discovered new brain cells developing in the hippocampus of mice treated with electroconvulsive therapy.
Studies on humans have shown similar results. In 2015, for example, it was found that electroconvulsive therapy works to "reshape" the brain structures of some patients with major depressive disorder, reforming neural connections in the amygdala and hippocampus. Meanwhile, antidepressant medications are associated with neuroplasticity in the hippocampus and the prefrontal cortex, and cognitive behavioral therapy is linked to changing brain activation in the prefrontal cortex and the cerebral cortex, which are associated with mental imagery and memory.
Despite being evidence-based, these depression treatments are not always equally effective, nor do they lead to consistent levels of structural changes in the brain. The brain is an incredibly complex structure, and human emotions are highly intricate. Attempting to separate the two is an exceedingly difficult task, but this has not deterred scientists from trying.
