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Frontiers in Neuroscience 2023Cognitive loss in older adults is a growing issue in our society, and there is a need to develop inexpensive, simple, effective in-home treatments. This study was... (Review)
Review
OBJECTIVE
Cognitive loss in older adults is a growing issue in our society, and there is a need to develop inexpensive, simple, effective in-home treatments. This study was conducted to explore the use of olfactory enrichment at night to improve cognitive ability in healthy older adults.
METHODS
Male and female older adults ( = 43), age 60-85, were enrolled in the study and randomly assigned to an Olfactory Enriched or Control group. Individuals in the enriched group were exposed to 7 different odorants a week, one per night, for 2 h, using an odorant diffuser. Individuals in the control group had the same experience with amounts of odorant. Neuropsychological assessments and fMRI scans were administered at the beginning of the study and after 6 months.
RESULTS
A statistically significant 226% improvement was observed in the enriched group compared to the control group on the Rey Auditory Verbal Learning Test and improved functioning was observed in the left uncinate fasciculus, as assessed by mean diffusivity.
CONCLUSION
Minimal olfactory enrichment administered at night produces improvements in both cognitive and neural functioning. Thus, olfactory enrichment may provide an effective and low-effort pathway to improved brain health.
PubMed: 37554295
DOI: 10.3389/fnins.2023.1200448 -
Neuropsychology Review Mar 2024Olfactory training (OT), or smell training,consists of repeated exposure to odorants over time with the intended neuroplastic effect of improving or remediating... (Review)
Review
Olfactory training (OT), or smell training,consists of repeated exposure to odorants over time with the intended neuroplastic effect of improving or remediating olfactory functioning. Declines in olfaction parallel declines in cognition in various pathological conditions and aging. Research suggests a dynamic neural connection exists between olfaction and cognition. Thus, if OT can improve olfaction, could OT also improve cognition and support brain function? To answer this question, we conducted a systematic review of the literature to determine whether there is evidence that OT translates to improved cognition or altered brain morphology and connectivity that supports cognition. Across three databases (MEDLINE, Scopus, & Embase), 18 articles were identified in this systematic review. Overall, the reviewed studies provided emerging evidence that OT is associated with improved global cognition, and in particular, verbal fluency and verbal learning/memory. OT is also associated with increases in the volume/size of olfactory-related brain regions, including the olfactory bulb and hippocampus, and altered functional connectivity. Interestingly, these positive effects were not limited to patients with smell loss (i.e., hyposmia & anosmia) but normosmic (i.e., normal ability to smell) participants benefitted as well. Implications for practice and research are provided.
Topics: Humans; Brain; Cognition; Olfaction Disorders; Olfactory Training; Smell
PubMed: 36725781
DOI: 10.1007/s11065-022-09573-0 -
Annual Review of Pharmacology and... Jan 2024Adverse nocebo responses can cause harm to patients and interfere with treatment adherence and effects in both clinic practice and clinical trials. Nocebo responses... (Review)
Review
Adverse nocebo responses can cause harm to patients and interfere with treatment adherence and effects in both clinic practice and clinical trials. Nocebo responses refer to negative outcomes to active medical treatments in clinical trials or practice that cannot be explained by the treatment's pharmacologic effects. Negative expectancies and nocebo effects are less known than placebo responses. Nocebo effects can be triggered by verbal suggestions, prior negative experiences, observation of others experiencing negative outcomes, and other contextual and environmental factors. As research advances over the years, mechanistic knowledge is accumulating on the neurobiological mechanisms of nocebo effects. This review summarizes studies on different facets of nocebo effects and responses and discusses clinical implications, ethical considerations, and future directions.
Topics: Humans; Nocebo Effect; Placebo Effect
PubMed: 37585661
DOI: 10.1146/annurev-pharmtox-022723-112425 -
Journal of Affective Disorders Oct 2023Depression and dementia are highly prevalent in older adults and often co-occur. This Phase IV study investigated the effectiveness and tolerability of vortioxetine in...
BACKGROUND
Depression and dementia are highly prevalent in older adults and often co-occur. This Phase IV study investigated the effectiveness and tolerability of vortioxetine in improving depressive symptoms, cognitive performance, daily and global functioning and health-related quality of life (HRQoL) in patients with major depressive disorder (MDD) and comorbid early-stage dementia.
METHODS
Patients (n = 82) aged 55-85 years with a primary diagnosis of MDD (onset before age 55 years) and comorbid early-stage dementia (diagnosed ≥6 months before screening and after onset of MDD; Mini-Mental State Examination-2 total score, 20-24) received vortioxetine for 12 weeks (initiated at 5 mg/day and up-titrated to 10 mg/day at day 8, with flexible dosing thereafter [5-20 mg/day]). The primary endpoint was change from baseline in Montgomery-Åsberg Depression Rating Scale (MADRS) total score at week 12.
RESULTS
Significant improvement in depressive symptom severity was seen from week 1 onwards (P < 0.0001). At week 12, the least-square mean (standard error) change in MADRS total score from baseline was -12.4 (0.78). Significant improvements in cognitive performance were observed (from week 1 for the Digit Symbol Substitution Test and week 4 for the Rey Auditory Verbal Learning Test). Patients also experienced significant improvements in daily and global functioning, and HRQoL. Vortioxetine was well tolerated. From week 4 onwards, more than 50 % of patients were receiving 20 mg/day.
LIMITATIONS
Open-label study.
CONCLUSIONS
Vortioxetine demonstrated effectiveness in clinically significantly improving depressive symptoms, cognitive performance, daily and global functioning, and HRQoL in patients with MDD and comorbid early-stage dementia treated for 12 weeks.
TRIAL REGISTRATION
ClinicalTrials.gov/ct2/show/NCT04294654.
Topics: Humans; Aged; Vortioxetine; Depressive Disorder, Major; Quality of Life; Piperazines; Double-Blind Method; Dementia; Treatment Outcome; Sulfides
PubMed: 37315590
DOI: 10.1016/j.jad.2023.06.024 -
Journal of Affective Disorders Oct 2023Recent studies indicate accelerated ageing processes, shorter telomere length and poorer cognitive functioning in patients with bipolar disorder. The neurobiology...
INTRODUCTION
Recent studies indicate accelerated ageing processes, shorter telomere length and poorer cognitive functioning in patients with bipolar disorder. The neurobiology underlying cognitive function in bipolar disorder is yet to be established. We anticipated that accelerated ageing as indicated by shortened telomere length, would be associated with reduced cognitive performance in bipolar disorder, particularly for ageing sensitive functions such as memory and learning.
METHODS
The study consisted of 647 participants (bipolar disorder [n = 246] and healthy controls [n = 401]). All participants underwent a standardized neuropsychological test battery, including working memory, executive functioning, processing speed, verbal learning, and verbal memory. Leucocyte telomere length was measured via blood and determined by quantitative real-time Polymerase Chain Reaction (qPCR) providing a telomere to single copy ratio (T/S ratio). The T/S ratio was used as an estimate of the mean telomere length of each participant. All analyses were adjusted for medication, Daily Defined Dose (DDD), chronological age, sex, and ethnicity.
RESULTS
Patients had shorter telomere lengths than healthy controls (Cohen's d = 0.11, p = 0.01). Within patients', a positive association was observed for verbal learning and telomere length (β = 0.14, p = 0.025), along with a trend for verbal memory and telomere length (β = 0.11, p = 0.07). No other associations were observed for telomere length and cognitive functioning in the patient or the control group (p > 0.1).
CONCLUSION
Our study may suggest poorer brain health in bipolar disorder as indexed by shorter telomere length and reduced learning correlates. However, the role of telomere length on cognitive functioning in bipolar disorder seems limited.
Topics: Humans; Bipolar Disorder; Telomere Shortening; Telomere; Neuropsychological Tests; Memory, Short-Term; Verbal Learning
PubMed: 37459977
DOI: 10.1016/j.jad.2023.07.087 -
Frontiers in Human Neuroscience 2024Human creativity is a powerful cognitive ability underlying all uniquely human cultural and scientific advancement. However, the neuronal basis of this creative ability... (Review)
Review
Human creativity is a powerful cognitive ability underlying all uniquely human cultural and scientific advancement. However, the neuronal basis of this creative ability is unknown. Here, I propose that slow, spontaneous fluctuations in neuronal activity, also known as "resting state" fluctuations, constitute a universal mechanism underlying all facets of human creativity. Support for this hypothesis is derived from experiments that directly link spontaneous fluctuations and verbal creativity. Recent experimental and modeling advances in our understanding of the spontaneous fluctuations offer an explanation for the diversity and innovative nature of creativity, which is derived from a unique integration of random, neuronal noise on the one hand with individually specified, deterministic information acquired through learning, expertise training, and hereditary traits. This integration between stochasticity and order leads to a process that offers, on the one hand, original, unexpected outcomes but, on the other hand, endows these outcomes with knowledge-based meaning and significance.
PubMed: 38476979
DOI: 10.3389/fnhum.2024.1367922