Ketamine for Depression in Older Adults

Effectiveness of pharmacological and non-pharmacological interventions for treatment-resistant depression in older patients: a systematic review and meta-analysis

BACKGROUND

Depression in older adults is often undertreated. A 2011 systematic review of treatments for treatment-resistant depression (TRD) in older adults identified one placebo-controlled randomised controlled trial (RCT). We aimed to update this review, synthesising evidence for the effectiveness of treatments for TRD in older people.

METHODS

We systematically searched electronic databases (PubMed, Cochrane, Web of Science) from 9 January 2011 through 10 December 2023 (updating our search on 7 January 2024 for RCTs investigating TRD therapies in adults aged ≥55 years, defining treatment resistance as ≥1 unsuccessful treatment. We assessed bias with the Cochrane Risk of Bias (RoB) 2 tool, meta-analysed remission rates and evaluated evidence using GRADE (Grading of Recommendations Assessment, Development, and Evaluation) criteria.

RESULTS

14 studies (11 newly identified, 3 from previous review) involving 1196 participants (mean age 65.0, male/female 548/648) met the inclusion criteria; 10 were placebo controlled and 4 were rated as low RoB. The pooled proportion of participants in intervention arms remitting was 0.35 (17 arms; 95% CI=0.26; 0.45). Relative to placebo, intervention participants were more likely to remit (9 studies; OR 2.42 (95% CI=1.49; 3.92)). Relative to controls, remission rates favoured ketamine (n=3; OR 2.91 (1.11; 7.65)), with a trend towards transcranial magnetic stimulation (TMS) (n=3; 1.99 (0.71; 5.61)), and in single placebo-controlled studies, selegiline, aripiprazole augmentation, pharmacogenetic-guided prescribing (PGP) and cognitive remediation favoured interventions.

CONCLUSIONS

We identified weak evidence that ketamine therapy and aripiprazole augmentation, and very weak evidence that TMS, PGP and cognitive remediation increased remission. Lack of evidence regarding routinely prescribed antidepressants and psychosocial treatments is problematic, requiring clinicians to extend evidence from younger populations.

PROSPERO REGISTRATION NUMBER

CRD42023494513.

Biological factors influencing depression in later life: role of aging processes and treatment implications

Late-life depression occurring in older adults is common, recurrent, and malignant. It is characterized by affective symptoms, but also cognitive decline, medical comorbidity, and physical disability. This behavioral and cognitive presentation results from altered function of discrete functional brain networks and circuits. A wide range of factors across the lifespan contributes to fragility and vulnerability of those networks to dysfunction. In many cases, these factors occur earlier in life and contribute to adolescent or earlier adulthood depressive episodes, where the onset was related to adverse childhood events, maladaptive personality traits, reproductive events, or other factors. Other individuals exhibit a later-life onset characterized by medical comorbidity, pro-inflammatory processes, cerebrovascular disease, or developing neurodegenerative processes. These later-life processes may not only lead to vulnerability to the affective symptoms, but also contribute to the comorbid cognitive and physical symptoms. Importantly, repeated depressive episodes themselves may accelerate the aging process by shifting allostatic processes to dysfunctional states and increasing allostatic load through the hypothalamic-pituitary-adrenal axis and inflammatory processes. Over time, this may accelerate the path of biological aging, leading to greater brain atrophy, cognitive decline, and the development of physical decline and frailty. It is unclear whether successful treatment of depression and avoidance of recurrent episodes would shift biological aging processes back towards a more normative trajectory. However, current antidepressant treatments exhibit good efficacy for older adults, including pharmacotherapy, neuromodulation, and psychotherapy, with recent work in these areas providing new guidance on optimal treatment approaches. Moreover, there is a host of nonpharmacological treatment approaches being examined that take advantage of resiliency factors and decrease vulnerability to depression. Thus, while late-life depression is a recurrent yet highly heterogeneous disorder, better phenotypic characterization provides opportunities to better utilize a range of nonspecific and targeted interventions that can promote recovery, resilience, and maintenance of remission.

Pharmacological management of neuropsychiatric symptoms in geriatric traumatic brain injury: a scoping review

OBJECTIVE

This scoping review aimed to summarize the existing knowledge base on the pharmacological management of neuropsychiatric symptoms in geriatric TBI and identify gaps in the literature to guide future research.

METHODS

Seven electronic databases and nine gray literature databases were systematically searched for articles that examined pharmacological management of neuropsychiatric symptoms in adults aged 65 years and over with TBI. The search was guided by four main concepts and selected based on inclusion criteria. Unpublished studies and abstract-only articles were excluded.

RESULTS

Eight studies met full inclusion criteria. Patterns of psychotropic medication prescription and prescribing principles for geriatric TBI were elucidated. There were no clear or consistent prescribing guidance. Therefore, prescribing recommendations could not be addressed. Current management is inferred from research primarily done in younger adults, or extrapolated from the literature and practice of treating other psychiatric and neurological disorders.

CONCLUSION

There are significant gaps in knowledge and no evidence-based guidelines for the treatment of neuropsychiatric symptoms in geriatric TBI. TBI among older adults is distinct from those of younger adults and thereby demands a unique approach to treatment and research. The authors' proposed guideline is an important first step in facilitating guideline development and future research.

Potential advantages of ketamine over electroconvulsive therapy in the treatment of nonrefractory severe depression in older patients with multiple medical comorbidities

Depression in older adults with multiple medical comorbidities can contribute to clinical deterioration, and increased mortality. Electroconvulsive therapy (ECT) is the first-line treatment for these patients. This study aimed to evaluate the effectiveness and safety of subcutaneous (SC) ketamine as an alternative to ECT. We reviewed the medical records of all consecutive older inpatients with severe depression and multiple medical comorbidities who were referred for ECT but treated with SC ketamine over 1 year in our institution. Demographic data, DSM-5 diagnosis, MÅDRS score, and CGI score were analyzed. Twelve patients aged 67-94 years were included. All patients were rated as severely ill, 83% were women, with a mean of 12.6 (SD, 1.4) medical comorbidities. Remission was achieved in 75% of the intention-to-treat population and 100% of treatment completers. The number of sessions ranged from 1 to 6, and days until remission from 1 to 16. Patients remained without relapse for 8-28 months. SC ketamine was safe and well tolerated, and most adverse events were mild and transient. Although limited by the retrospective open-label design of the study and small sample size, our findings provide a potential new indication for ketamine: treatment of severe depression, not necessarily resistant to antidepressants, in older patients with multiple medical comorbidities, at risk of clinical deterioration, and referral for ECT. SC ketamine was highly effective in this population, with no relapse and good tolerance. Randomized controlled trials are needed to adequately test the use of ketamine in this specific group.