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In people with mild cognitive impairment or dementia, cognitive training reduces depression by a moderate amount

Chan JYC, Chan TK, Kwok TCY, et al. Cognitive training interventions and depression in mild cognitive impairment and dementia: a systematic review and meta-analysis of randomized controlled trials. Age Ageing. 2020; 49:738-47.

Review question

In people who have mild cognitive (thinking) impairment or dementia, does cognitive training reduce the severity of depression symptoms?


Decline in cognitive ability and dementia are common in older adults, and people who have cognitive impairment or dementia often also have depression. Cognitive training interventions (e.g., standardized tasks that “exercise the brain”) can improve thinking in people with cognitive impairment, but it is not known whether cognitive training interventions can also reduce the severity of their depression.

How the review was done

The researchers did a systematic review of studies available up to April 2019. They found 36 randomized controlled trials that included a total of 2551 people.

Key features of the studies were

  • the average age was 63 to 88 years;
  • people had mild cognitive impairment, mild-to-moderate dementia, or any level of dementia;
  • people lived in the community of in nursing homes or long-term care facilities;
  • cognitive training included
    • computerized cognitive training (uses computers to direct people to perform specific tasks)
    • cognitive training and rehabilitation (personalized guided practice of tasks that require specific cognitive functions such as attention and memory)
    • cognitive stimulation therapy (professional-led program of themed activities such as reminiscence therapy, which uses sight, sound, touch, taste, and smell to help people remember events, people, and places from their past);
  • cognitive training was provided for 2 to 52 weeks; and
  • cognitive training was compared with usual care, social and recreational activity, or alternative psychosocial interventions.

What the researchers found

Compared with control, depression severity was reduced by

  • a moderate amount by cognitive training interventions overall;
  • a moderate amount by computerized cognitive training;
  • a small amount by cognitive training and rehabilitation; and
  • a moderate amount by cognitive stimulation therapy.


In people who have mild cognitive impairment or dementia, cognitive training reduces the severity of depression symptoms.

Effects of cognitive training vs control on depression in people who have mild cognitive impairment or dementia

Types of cognitive training

Number of studies (number of people)

Effect of cognitive training

All types of cognitive training

36 studies (2414 people)

Cognitive training reduced depression severity by a moderate amount.

Computerized cognitive training

7 studies (228 people)

Computerized cognitive training reduced depression severity by a moderate amount.

Cognitive training and rehabilitation

16 studies (1123 people)

Cognitive training and rehabilitation reduced depression by a small amount.

Cognitive stimulation therapy

14 studies (1114 people)

Cognitive stimulation training reduced depression severity by a moderate amount.



Cognitive function
Mental processes, including thinking, learning and remembering.
Cognitive impairment
Trouble remembering, learning new things, concentrating, or making decisions that affect everyday life.
Randomized controlled trials
Studies where people are assigned to one of the treatments purely by chance.
Systematic review
A comprehensive evaluation of the available research evidence on a particular topic.

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DISCLAIMER These summaries are provided for informational purposes only. They are not a substitute for advice from your own health care professional. The summaries may be reproduced for not-for-profit educational purposes only. Any other uses must be approved by the McMaster Optimal Aging Portal (

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