Are psychological treatments useful for reducing depression and anxiety in dementia and mild cognitive impairment?

Dementia is a disorder in which cognition is impaired, severely affecting the capacity of the individual to carry on with their own daily activities. Mild cognitive impairment (MCI) is a condition in which the level of cognitive impairment does not significantly affect the capacity to carry on daily activities. Eventually, a proportion of people with MCI will develop dementia.

People with dementia have two times the probability of being diagnosed with major depressive disorder and have a higher probability of anxiety disorders. These concomitant conditions increase the severity of neurological impairment and severely affect independence, thus increasing the caregiver burden. In this scenario, psychotherapy aims to modify dysfunctional beliefs and implement behavioural strategies. Particularly modern approaches to treating depression and anxiety rely on cognitive behavioural therapy (CBT), behavioural activation (BA), problem-solving therapy (PST), interpersonal therapy (IPT), and complementary approaches. This review investigated whether compared with treatment as usual, psychological interventions may be helpful to reduce depression and anxiety in people with dementia or MCI.

This review is important for

People with dementia or MCI with concomitant depression and anxiety disorders, their loved ones/caregivers, health professionals caring for this population, general practitioners, researchers, and policymakers.

Outcomes of this review

This is an update of a Cochrane Systematic Review (CSR) published in 2014. The outcomes analysed were measures of depression and anxiety and other neuropsychiatric symptoms, remission from depression, quality of life, performance in activities of daily living (ADL), and cognition. The review also analysed caregivers' outcomes such as quality of life, burden, and depressive symptoms.

The CSR included 29 studies published and/or registered between 1997 and 2020, with 2,599 participants. Results showed that, compared to treatment, as usual, CBT probably slightly ameliorates symptoms of depression, quality of life, and performance in daily activities in people with dementia or MCI. The authors were uncertain of the effects of CBT and supportive and counselling treatments on anxiety. The latter treatments may have no effects on depression. Very few studies looked at mindfulness-based therapies or interpersonal therapies so no conclusion could be drawn. Moreover, for any treatment, there was a lack of information about undesired effects.

These results must be interpreted with caution because (i) most people had dementia of mild to moderate severity, so the results may not be applicable to other cases at the extremes; (ii) very few studies included only people who had significant levels of depression before treatment; and (iii) there is insufficient evidence to support any type of treatment to benefit a specific population of dementia or MCI patients.

Author’s conclusion of the review

Compared to treatment as usual, CBT probably slightly ameliorates symptoms of depression, quality of life, and performance in daily activities in people with dementia or MCI, as it may also increase the rates of remission of depression. It should be noted that there may be important confounders like the degree of depression before dementia, cognitive diagnosis, or content of the intervention.

Supportive and counselling interventions may not improve symptoms of depression in people with dementia. It is uncertain whether the treatments produced any improvement in anxiety. The authors were uncertain whether other types of psychological treatments may have any favourable effect and whether those effects persisted over time.

Future recommendations

The authors recommended that large-scale, high-quality clinical studies are needed, particularly to find out (a) the effects of treatments over time, after long-term follow-up; and (b) whether treatment efficacy is affected by the severity of dementia. The studies should examine (c) the different components of these interventions and (d) the application for specific populations and settings. Future studies should also assess (e) the cost-effectiveness of these treatments and the benefits in terms of reduction in social care costs. Future studies may be most useful if focused on well-defined psychological approaches, without combining an array of different treatments. Baseline depression and anxiety should be noted. Research should also focus on (f) standardizing MCI definition and interventions to allow correct data pooling; and (g) exploring and developing new treatments together with service users.

Sara Liguori