The neural correlates of perceived energy levels in older adults with late-life depression

Internet use, physical activity and depressive symptoms in older adults: A cross-lagged panel analysis

BACKGROUND

Existing cross-sectional studies suggest a strong positive association between Internet use, physical activity, and mental health in older adults; however, longitudinal studies reporting the relationship between Internet use, physical activity, and levels of depressive symptoms in older adults are lacking. This study aimed to examine the bidirectional relationship between Internet use and depressive symptoms in older adults and its underlying mechanisms.

METHODS

We used two waves of follow-up data (2016 and 2018) from the China Family Panel Studies, including 5837 participants aged 60 years or above. The bidirectional relationship between Internet usage time and depressive symptoms was examined using a cross-lagged model. The mediating role of physical exercise was examined using a half-longitudinal mediation model.

RESULTS

The results revealed a bidirectional relationship between Internet use time, frequency of physical activity, and depressive symptoms. Longer Internet use predicted lower levels of depressive symptoms, and the frequency of physical activity mediated the longitudinal relationship between Internet use and depressive symptoms in older adults.

LIMITATIONS

First, our study used self-report-based variables. Second, our study did not obtain the specific timing of the application of various functions of the Internet and the intensity of physical activity among older adults. Finally, based on the availability of data, our study involved only two waves of data. This may not be sufficient for a full longitudinal mediation effect test.

CONCLUSIONS

Internet use and depressive symptoms were interrelated over time among older adults. The frequency of physical activity was a mediator of Internet use and depressive symptoms. This underscores the importance of Internet-based technologies to enable healthy living and prevent depression and loneliness in older adults.

Association of White Matter Integrity With Executive Function and Antidepressant Treatment Outcome in Patients With Late-Life Depression

OBJECTIVE

While patients with late-life depression (LLD) often exhibit microstructural white matter alterations that can be identified with diffusion tensor imaging (DTI), there is a dearth of information concerning the links between DTI findings and specific cognitive performance, as well as between DTI measures and antidepressant treatment outcomes.

DESIGN

Neuroimaging and cognitive tests were conducted at baseline in 71 older adults participating in a larger, 8-week duration antidepressant randomized controlled trial. Correlations between DTI measures of white matter integrity evaluated with tract-based spatial statistics, baseline neurocognitive performance, and prospective antidepressant treatment outcome were evaluated.

RESULTS

Fractional anisotropy (FA), an index of white matter integrity, was significantly positively associated with better cognitive function as measured by the Initiation/Perseveration subscale of the Dementia Rating Scale in the bilateral superior longitudinal fasciculus (SLF), bilateral SLF-temporal, and right corticospinal tract (CST). An exploratory analysis limited to these tracts revealed that increased FA in the right CST, right SLF, and right SLF-temporal tracts was correlated with a greater decrease in depressive symptoms. Increased FA in the right CST predicted a greater chance of remission, while increased FA in the right CST and the right SLF predicted a greater chance of treatment response.

CONCLUSION

In late-life depression LLD subjects, white matter integrity was positively associated with executive function in white matter tracts which act as key connecting structures underlying the cognitive control network. These tracts may play a role as a positive prognostic factor in antidepressant treatment outcome.

Cognitive reserve-mediated neural modulation of emotional control and regulation in people with late-life depression

Late-life depression (LLD) is an affective disorder that is highly prevalent among older people. Cognitive reserve (CR) refers to an active process that facilitates the flexibility and efficiency of the neural networks to compensate for impairments that emerge in consequence of brain pathology. The current functional magnetic resonance imaging study investigated whether and how CR affects emotional regulation, level of depression severity and neural activity associated with affective control during emotional Stroop (eStroop) task. Altogether, 90 older people participated in this study, 50 of whom suffered from LLD. We used years of education and verbal fluency capacity as proxies for CR. Clinical participants with relatively higher CR presented with milder degrees of depression, better eStroop performance and stronger neural activity in the middle frontal gyrus (MFG) involved with exercising affective control. Results of the mediation analysis indicated that both education and verbal fluency significantly mediated the association between the depression severity and MEG activity. These results suggest a negative association between CR and age-related clinical symptoms of emotional dysregulation. Our neurobehavioral findings provide supportive evidence that CR implies efficiency of top-down emotional regulation and operates as a protective factor against emotional and cognitive vulnerability in the aging brain.