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PACt-MD study

The PACt-MD (Prevention of Alzheimer’s Dementia with Cognitive Remediation plus Transcranial Direct Current Stimulation in Mild Cognitive Impairment and Depression) study is combining two novel interventions to determine whether they can prevent or delay the onset of Alzheimer’s dementia.

Current treatments for Alzheimer’s dementia (AD) start after a patient already shows symptoms of dementia. Older adults with depression or mild cognitive impairment have a significantly elevated risk for AD, even if they do not yet show symptoms. However, there are currently no preventive treatments to protect these older adults against AD. This study is examining the combination of two novel interventions – transcranial direct current stimulation (tDCS) and cognitive remediation therapy – to protect against AD in patients with depression or mild cognitive impairment.

The study is funded by Brain Canada and carried out by researchers in CAMH's Geriatric Psychiatry Division in collaboration with Baycrest, St. Michael’s Hospital, Sunnybrook Health Sciences Centre and University Health Network.


What is mild cognitive impairment?

Mild cognitive impairment is a significant decline in a person’s cognitive ability, such as memory, learning, attention and planning, that is noticeable in daily life. However, this decline is not so severe that it interferes with independent living. Some cognitive lapses are a normal part of aging. For example, it is normal to momentarily forget a person’s name, or where you put your keys. Frequent lapses, or more serious lapses such as forgetting conversations or appointments, may be symptoms of mild cognitive impairment. In some, but not all, cases, mild cognitive impairment can be an early warning sign of dementia.


What is depression?

Depression is a mood disorder characterized by feelings of hopelessness, sadness and despair. Other symptoms may include irritability, fatigue, loss of interest in enjoyable activities, withdrawal from social or family life and sleep or appetite issues. Depression usually involves one or more major depressive episodes with periods of feeling somewhat better between these episodes. Although it can be difficult to talk about these kinds of feelings, they are not a normal part of aging and can be managed with appropriate care.


What is transcranial direct current stimulation?

Transcranial direct current stimulation (tDCS) is a type of painless, non-invasive brain stimulation that is delivered while a participant is awake and alert. tDCS circulates a very small electrical current through the head (less than 1% of the current in a lightbulb). This current stimulates brain cells and improves learning and memory. People usually feel a warming or tingling sensation on the skin during tDCS.


What is cognitive remediation?

Cognitive remediation (CR) is a form of cognitive training in which a therapist guides a small group through a series of brain training exercises. It is used to enhance cognitive skills such as learning, memory, attention and planning.


How does this study work?

Older adults with depression (age 65+) or mild cognitive impairment (age 60+) will attend a screening visit and then complete the following assessments:

  • A clinical assessment for depression, mild cognitive impairment and other conditions
  • A neuropsychological evaluation including tests of attention, memory and problem solving
  • Optional genetic testing
  • Optional lumbar puncture
  • Optional brain imaging: magnetic resonance imaging (MRI) and positron emission tomography (PET)

Eligible participants will be randomly assigned (similar to a coin toss) to one of two different groups. The two groups will receive two types of treatment with different levels of electrical and cognitive stimulation. Both groups will attend daily sessions, including tDCS brain stimulation and cognitive remediation, for eight weeks.

One benefit of this study is long-term follow-up. For up to five years, a multidisciplinary geriatric psychiatry team will closely monitor each participant’s condition. Participants will receive an additional week of tDCS and cognitive remediation sessions once every six months, as well as clinical and neuropsychological assessments once per year.

Participants can withdraw from the study at any time. Reimbursement will be provided for participants’ time and study-related expenses such as transportation.


How can I get more information?

If you are interested in participating in this study, or if you have a patient, friend or family member who would be interested, please leave us a detailed message on the confidential PACt-MD voice-mail line at 416-583-1350 or contact us by e-mail at​​


 Research team


Lead principal investigator: 
Dr. Benoit Mulsant

Co-principal investigators: 
Dr. Nathan Hermann
Dr. Bruce Pollock
Dr. Tarek Rajji


 Contact us


​To find out more about this study, please e-mail us at or leave a confidential voice-mail message at 416-583-1350.

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