New study shows combination therapy slows cognitive decline in at-risk populations

An important new study, published today in JAMA Psychiatry, has demonstrated that a combination therapy can slow cognitive decline in older adults at risk for dementia. The study was made possible through the collaboration of researchers at several Toronto Dementia Research Alliance (TDRA) partner sites including Sunnybrook Health Sciences Centre, the Centre for Addiction and Mental Health (CAMH), Baycrest, Unity Health Toronto and University Health Network (UHN).

The trial focused on preventing cognitive decline in older adults with a condition that increases the risk for dementia: Major Depressive Disorder in remission (rMDD), Mild Cognitive Impairment (MCI), or both.

The study involved 375 older adults who received either a control (“sham”) intervention or a combination of two active therapies: the first involved specially designed Cognitive Remediation (CR) techniques—therapeutic interventions designed to improve cognitive functioning, like puzzles and logic problems. The second was transcranial direct current stimulation (tDCS)—a form of non-invasive brain stimulation. These therapies were delivered five days per week for eight weeks, followed by 5-day "boosters" every six months. The study was randomized, controlled, and double-masked, with assessments conducted at baseline, month-2, and yearly for three to seven years.

The study found that participants receiving CR plus tDCS experienced slower cognitive decline over a median follow-up period of 4 years compared to those receiving the control intervention. The effects were more prominent in individuals with low genetic risk for Alzheimer's disease, and participants with rMDD (with or without MCI) showed better outcomes than those with MCI alone.

“The results of this trial show us that combination therapies have the potential to improve the quality of life of individuals at-risk for dementia,” says Dr. Krista Lanctôt, Bernick Chair in Geriatric Psychopharmacology, senior scientist in the Hurvitz Brain Sciences Research Program and co-author of the study. “By slowing down cognitive decline, vulnerable populations can achieve prolonged independence.”

Cognitive decline is often the result of overlapping conditions, making combination therapies especially pertinent – they can improve patient outcomes by targeting different disease pathways in a synergistic way.

See the full joint-release from CAMH and TDRA for more information.