Mechanisms and Treatment of Late-Life Depression

Acute hyper-hypoxia accelerates the development of depression in mice via the IL-6/PGC1α/MFN2 signaling pathway

Background

Neural cell damage is an important cause of exacerbation of depression symptoms caused by hypoxia, but the mechanism behind it is still unclear. The purpose of this study is to elucidate the role of peroxisome proliferator-activated receptor gamma coactivator 1-alpha (PGC1α)/mitofusin-2 (MFN2) signaling axis in the development of depression in mice under hypoxia.

Methods

Male Institute of Cancer Research mice (age, 6 weeks) were assigned to the normal group, chronic unpredictable mild stress group (CUMS group), or CUMS + hyper-hypoxia group (CUMS + H group). Mice in the CUMS and CUMS + H groups were exposed to CUMS for 28 days. Additionally, mice in the CUMS + H group were exposed to acute hyper-hypoxia from Day 21 for 7 days. After a total of 28 days, behavioral experiments were conducted. All mice were anesthetized and sacrificed. Levels of brain tissue interleukin (IL)-6, reactive oxygen species (ROS), adenosine triphosphate (ATP), and serotonin (5-HT) were analyzed.

Results

As compared to the CUMS group, mice in the CUMS + H group had increased IL-6 and ROS levels, but lower open-field activity, preference for sucrose, hippocampal neuronal membrane potential, ATP, and 5-HT levels, as well as MFN2 and PGC1α levels.

Conclusions

Acute hyper-hypoxia plays an important role in the development of depression via the IL-6/PGC1α/MFN2 signaling pathway.

Effectiveness of Psychotherapy for Community-Dwelling Vulnerable Older Adults with Depression and Care Needs: Findings from the PSY-CARE Trial

BACKGROUND

For older adults with care needs, evidence for the effectiveness of psychotherapy on depression is scarce.

METHODS

In PSY-CARE, a pragmatic randomized controlled trial, N = 197 home-living older adults with depression and care needs were randomized into outpatient psychotherapy or an active control condition. Residential psychotherapists offered age-sensitive cognitive-behavioral psychotherapy (at-home if needed). Control group participants received telephone counseling and a self-help guide. Outcomes were assessed at baseline (T1), after (T2), 3 months after (T3), and 12 months after the intervention (T4).

RESULTS

There was a significant decrease in depressive symptoms across both arms with Cohen's d T4-T1 = .52 in the psychotherapy and .55 in the control group. Mixed models revealed no statistically significant difference in primary and secondary outcomes between interventions. Posthoc, we found control group participants with greater ADL limitations experienced significantly increased depressive symptoms compared to those reporting lower limitations.

CONCLUSIONS

Interventions were successful in reducing depressive symptoms, even though treatment fidelity was decreased due to the COVID-19 pandemic. We could not demonstrate superior effectiveness of psychotherapy for older adults with care needs.

CLINICAL IMPLICATIONS

Findings suggest that psychotherapy may be an important and superior treatment to circumvent aggravation of depression in older patients with high functional limitations.

TRIAL REGISTRATION

The trial was prospectively registered with the ISRCTN registry (Trial registration number: ISRCTN55646265, February 15, 2019).

The cognitive effects of adjunctive repetitive transcranial magnetic stimulation for late-onset depression: a randomized controlled trial with 4 week follow-up

Objectives

Cognitive impairment is common and linked to poor outcomes in patients with late-onset depression (LOD). The cognitive effects of repetitive transcranial magnetic stimulation (rTMS) for LOD are not well understood. This study aimed to investigate the effects of rTMS on cognitive function in elderly patients with LOD.

Methods

In total, 58 elderly patients (aged 60 to 75 years) with depression were enrolled and randomly assigned to an active rTMS group or a sham group. The participants received active or sham rTMS over the left dorsolateral prefrontal cortex for 4 weeks, 5 days a week, at a frequency of 10 Hz rTMS and 120% of the motor threshold (MT). Cognitive function was assessed using the Repeatable Battery for the Assessment of Neuropsychological Status (RBANS) at baseline, the end of the 4 week treatment period, and at the 4 week follow-up.

Results

The active rTMS group showed significant improvements in immediate memory and attention scores on the RBANS compared to the sham group. However, no significant differences were observed between the two groups in other cognitive domains assessed by the RBANS. No serious adverse events related to rTMS treatment were observed.

Conclusion

Treatment with 120% MT rTMS was associated with improvement in cognitive defects related to the active phase of LOD. These findings suggest that rTMS could provide early improvements in cognitive function in clinical settings for elderly patients with LOD.Clinical trial registration: https://www.chictr.org.cn/showproj.html?proj=40698, identifier ChiCTR1900024445.

Prediction of Antidepressant Efficacy by Cognitive Function in First-Episode Late-Life Depression: A Pilot Study

The response rate of treatment for late-life depression (LLD) is only 25-60%. The cognitive impairment associated with LLD often affects the effectiveness of antidepressants and may has the potential ability to predict response. This study seeks a biomarker for baseline cognitive function to predict efficacy of antidepressants. Sixty patients diagnosed with LLD received escitalopram or sertraline treatment for 8 weeks. Clinical symptom was measured using Hamilton Depression Rating Scale-17 (HAMD-17) and cognitive function was measured using the Repeatable Battery for the Assessment of Neuropsychological Status (RBANS), Trail Making Test (TMT) before and after 8-week treatment. Patients were divided into treatment effective group (TE) and treatment ineffective group (TI) according to reduction rate in scores of HAMD-17 after treatment. Thirty-eight matched healthy controls (HC) were assessed using RBANS and TMT. There was significant decrease of score of RBANS and increase of score of TMT in patients with LLD compared with HC. Regression analysis revealed that change in HAMD-17 score was significantly positively associated with baseline score of picture naming, figure copy, digit span, and delayed memory. The preliminary findings suggested that working memory, attention, visuospatial, language function, and delayed memory should be examined further as a means of providing the useful objective biomarkers of treatment response.

CLINICAL TRIALS REGISTRATION

[www.ClinicalTrials.gov], identifier [ChiCTR2100042370].