VIENNA, Austria — Antidepressants have the ability to rewire the human brain, according to new research. Scientists say the drugs alter the structure of grey and white matter, previously thought to be fixed, and returns it to a state of plasticity — normally only seen in kids.
Patients who respond best to treatment show a greater increase in connections between neurons.
“We found that treatment for depression changed the infrastructure of the brain, which goes against previous expectations. Treated patients showed a greater number of connections than they had shown before treatment. Moreover, those who showed the most response to treatment had developed a greater the number of new connections than those who showed little response. A second scan showing that there are no time effects in healthy controls supports our findings that we see something that is related to the disease and more importantly the treatment of this disease,” says lead author Professor Jonathan Repple in a media release.
“We found these changes took place over a period of only around 6 weeks, we were surprised at the speed of response. We don’t have an explanation as to how these changes take place, or why they should happen with such different forms of treatment.”
In children, changes in the brain occur as a natural result of growing up due to physical development and reorganization. It was thought to be generally rigid in adults, but the latest findings show this is not true.
What do brain scans reveal about antidepressants?
The team at Muenster University in Germany studied 109 patients with serious depression (Major Depressive Disorder) and compared them with 55 healthy controls. Brains were scanned using MRI (magnetic resonance imaging) to identify which parts were communicating — determining the level of connections.
The patients were then treated with medications, ECT (electroconvulsive therapy), psychological therapy, or a combination of all three. They were rescanned afterwards, and the number of connections recounted. These patients were also retested for symptoms of depression.
“This is a very interesting and difficult to perform study in which the authors repeated MRI-scans to reveal changes in structural connectivity over time in patients treated for depression,” adds Dr. Eric Ruhe from Rabdoud University Medical Center, who did not take part in this study.
“The results align very much with our current belief that the brain has much more flexibility in adaptation over (even short) time than was previously thought. Indeed a major idea of what treatment of depression (and other psychiatric illnesses) invoke is plastic changes over time. This has been proposed as a common mechanism for antidepressants, psychotherapy and electroconvulsive therapy,” Ruhe continues.
“However, the amount of research to elucidate what changes are necessary or specific for response to treatment or remission of the depression is limited. Moreover, the next question is whether different treatments have the possibility to specifically change targeted brain networks or vice versa whether we can use the disturbances in brain-networks as measured in the present study to choose which therapy will be helpful.”
“The fact that the observed changes over time could not be associated with a form of treatment is a pity, but as the authors themselves suggest a topic for further research. First these results should be replicated in independent samples which hopefully is going to happen soon. Second further elaboration on this approach would be daunting and should be supported firmly as this work might help to bridge the current gap between neuroscience and evidence based patient care.”
Depression is not ‘set in stone’
Depression is a common mental disorder that causes people to experience depressed mood, loss of interest or pleasure, feelings of guilt or low self-worth, disturbed sleep or appetite, low energy, and poor concentration.
Previous studies reveal that one in 10 Americans deal with depression. It’s the predominant mental health problem worldwide and the second leading cause of disability, behind lower back pain.
“This means that the brain structure of patients with serious clinical depression is not as fixed as we thought, and we can improve brain structure within a short time frame, around 6 weeks. We found that if this treatment leads to an increase in brain connectivity, it is also effective in tackling depression symptoms. This gives hope to patients who believe nothing can change and they have to live with a disease forever, because it is ‘set in stone’ in their brain,” Prof. Repple concludes.
The researchers presented their findings at the 35th European College of Neuropsychopharmacology annual conference.
South West News Service writer Mark Waghorn contributed to this report.