Promising depression treatment may soon be available in Ontario
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Question: My wife suffers from depression. She has tried the usual treatments like psychotherapy, cognitive-behaviour therapy and lots of different antidepressant medications. But nothing seems to help much. Now the doctors are suggesting she should try electroconvulsive therapy. But she is not interested in subjecting herself to electroshock – and I don’t blame her. Is there anything else that might lift her out of the blues?
Answer: Your wife is certainly not alone. About one-third of patients don’t get lasting relief from the standard therapies. But there is a relatively new treatment that may benefit your wife and other patients like her.
It’s called Repetitive Transcanial Magnetic Stimulation, or rTMS, and it’s essentially a treatment that uses magnetic field pulses to reset the circuits of the brain that control emotions.
It hasn’t yet received much public attention partly because it takes a lot of treatments to work and only two provinces – Quebec and Saskatchewan – currently pay for the therapy.
But you could soon be hearing a lot more about rTMS.
Two more provinces – Ontario and Alberta – are now considering adding rTMS to the list of treatments covered by their health insurance plans.
Even more important, researchers have been fine-tuning rTMS to make it accessible and effective for more patients.
Dr. Jonathan Downar, a psychiatrist and neuroscientist at Toronto Western Hospital, is one of the researchers leading the way.
“I am hoping we will be able deliver effective and affordable rTMS treatment to everyone who needs it,” he says.
To understand depression, he says, it helps to think of brain activity as traffic patterns in a big city.
“The brain is composed of billions of neurons that are organized into regions like neighbourhoods in a city,” he explains. Each of these regions performs a different function and they are all connected through networks that act like roads. Activity is suppose to ebb and flow between the various regions as the brain performs different functions.
In the case of depression, however, some areas involved in regulating emotions, thoughts and behaviours are overactive. This means some circuits, or roadways, in the brain get stuck in certain activity patterns preventing others from operating normally.
“Imagine if rush-hour traffic wasn’t just one or two hours, but lasted all day. The city would be gridlocked,” says Dr. Downar. “And what depression looks like on a brain scan is gridlock that doesn’t go away,” he said referring to areas of the brain that are unusually overactive.
The patients basically become preoccupied with negative thoughts and feelings and can’t get those ideas out of their heads.
Talk therapy can help some people break out of their mental gridlock. Others benefit from antidepressant medications that can alter brain activity.
But for those who don’t respond to either talk therapy or medication, rTMS may bring relief, says Dr. Downar who is the director of the MRI-guided rTMS clinic at Toronto Western Hospital.
“It’s an electro-magnet that can deliver finely focused magnetic-field pulses to anywhere in the brain to a depth of two to three centimetres,” he says. “We can use an MRI to guide it. And by applying repeated pulses over time, we can strengthen or weaken circuits that are overactive or underactive,” he explains.
“This is not a fridge magnet – this is a pretty powerful tool,” he adds. Earlier studies have shown that 50% of depressed patients experience an improvement in their symptoms, and a third said they were no longer depressed after completing the therapy. To put those figures into context, all of the patients who received rTMS had failed to respond to conventional therapies.
An added bonus is that rTMS is relatively free of long-term adverse effects. It doesn’t affect memory or attention – a common complaint of electroconvulsive therapy. There is a 1 in 10,000 chance of a seizure, but that’s about the same or less than the level of risk associated with antidepressant medications.
“All the effects are short term,” says Dr. Downar, and most patients can tolerate them. The magnetic pulses from the device “feel like an elastic band being snapped against your forehead,” he says. “You can get a headache afterwards for an hour or two – that usually goes away after the first week of treatment.”
Without question, rTMS sounds very promising. But there is a catch. It takes a lot of treatment sessions to get the desired results. With the standard course of treatment, patients require 20 to 30 separate sessions of treatment – each lasting 38 minutes.
Dr. Downar and his research team – with funding from the Ontario Brain Institute – have been searching for ways to shorten the overall treatment time. After reviewing findings from earlier studies, the researchers decided to adjust the stimulation so that it mimics theta rhythms – signals the brain naturally uses to alter its own activity patterns.
“Based on the data we have so far, it looks like three minutes is equivalent to 38 minutes using this approach,” he says. Patients still need 20 to 30 separate sessions. But, at just three minutes a treatment – instead of 38 – it may be possible to schedule several in a single day, shortening the time to recovery.
“We don’t want this to be taking four-to-six weeks with the person schlepping into the hospital every day for treatment,” he says. “We need to get this down to one or two weeks.”
Speedier therapy is good for patients, but it also makes the treatment much more cost effective for the health-care system – and that means more patients could potentially receive the therapy.
In another refinement of the treatment, Dr. Downar’s team changed the spot in the brain that’s stimulated with rTMS. Most of the earlier research focused the pulses on the dorsolateral prefrontal cortex – an area on the side of the frontal lobes. Instead, Dr. Downar stimulates an area called the dorsomedial prefrontal cortex, tucked away between the two hemispheres of the brain. This seems to boost the number of patients who experience full remission, rather than just feeling partially better.
“Not everybody responds to rTMS treatment, but with this new brain area, you get fewer partial responses. So if you do improve, you are more likely to get all the way to remission.”
Dr. Downar is very cautious not to call this treatment a cure. Some patients lapse back into depression after an average of about 10 months following the initial therapy. But “booster” treatments with rTMS can restore their mental wellbeing.
Once the depression lifts, the patients need to work on the life stressors that tend to push them over the edge, says Dr. Downar.
By breaking patients out of their mental gridlock, “we strengthen peoples’ ability for self-control,” explains Dr. Downar. “We are not pushing a happy button. We are improving their own ability to regulate their thoughts.”
If a job or a bad relationship is repeatedly sending a person into depression, then rTMS provides a window of opportunity to fix it. “What we are trying to do is get you to the point where you can climb the stairs yourself – this is not an escalator ride up.”
Dr. Downar is trying to develop a screening test to determine, in advance, which patients are most likely to benefit from rTMS – so depressed individuals won’t have to waste time on multiple treatments before realizing it’s not going to work for them.
He would also like to increase the treatment’s success rate above 50 per cent.
Some people might not benefit from rTMS because the source of their mental gridlock may be located deep in the brain – and out of reach of the electro-magnetic pulses.
Dr. Downar points out that neurosurgeons are already helping some severely depressed individuals by implanting electrodes that provide a steady stream of electric current to a region deep inside the brain – a therapy aptly named deep-brain stimulation.
He also notes that several companies are currently working on new and improved rTMS equipment designed to send electro-magnetic signals deeper into the brain than is currently possible. If they succeed, patients may be able to benefit from deep-brain stimulation without undergoing invasive and costly brain surgery, says Dr. Downar.
Other mental-health professionals also look upon rTMS as a potentially promising therapy.
“We wish we had one treatment that everyone responded to. We know that is certainly not the case. And so the broader the menu of options that we have, the better it is for our patients,” says Dr. Ayal Schaffer, head of the mood and anxiety disorders program at Sunnybrook Health Sciences Centre.
In addition to depression, rTMS may be useful for treating other conditions, such as anorexia nervosa, bulimia, obsessive-compulsive disorders and post-traumatic stress disorder, says Dr. Downar. Each of these conditions shares a common trait with depression. The brain is caught in a kind of endless loop and the patients can’t break out of it on their own.
Right now, in Ontario and most other provinces, rTMS is available only to a limited number of patients involved in studies funded by grants and donations.
If more provinces decide to fund rTMS, it would open up this treatment option to more and more patients – including possibly your wife.
Paul Taylor, Sunnybrook’s Patient Navigation Advisor, provides advice and answers questions from patients and their families, relying heavily on medical and health experts. His blog Personal Health Navigator is reprinted on Healthy Debate with the kind permission of Sunnybrook Health Sciences Centre. Email your questions to AskPaul@sunnybrook.ca and follow Paul on Twitter @epaultaylor