Grant: Project Grant

Canadians aged 60 and older are the fastest growing segment of the population. Depression is a very common illness later in life and is a major contributor to high rates of disability, poor quality of life, caregiver burden and poor health outcomes. Unfortunately, up to 77% of individuals treated for late-life depression (LLD) either do not respond to treatment or respond and then relapse. Strategies for managing treatment resistance in older adults are problematic due to increased sensitivity to side effects and higher rates of prescription drug use for other medical illnesses. There are very few safe and effective options for treating patients who do not respond to antidepressants. Repetitive transcranial magnetic stimulation (rTMS) involves stimulating the brain with a series of magnetic field pulses. A standard course treatment is administered daily, five days per week, for 45 minutes for 6 weeks. A newer form of rTMS called theta burst stimulation (TBS) capitalizes on the natural frequencies of brain waves and offers a more efficient way of stimulating. Specifically, a treatment session with TBS takes less than 5 minutes compared to the 45 minutes of a standard treatment. Underlying brain network dysfunction is thought to underlie depression in older adults. Functional brain imaging has the capacity to map brain network dysfunction. Certain patterns of brain network dysfunction may help to predict who is likely to respond to rTMS. By using brain imaging to predict who will respond to rTMS and exploring the effectiveness of TBS we will be able to greatly improve access and outcomes when using rTMS in older adults with depression.