Antidiabetes Agents and Incident Depression: A Nationwide Population-Based Study

Mitochondria and the Repurposing of Diabetes Drugs for Off-Label Health Benefits

This review describes our current understanding of the role of the mitochondria in the repurposing of the anti-diabetes drugs metformin, gliclazide, GLP-1 receptor agonists, and SGLT2 inhibitors for additional clinical benefits regarding unhealthy aging, long COVID, mental neurogenerative disorders, and obesity. Metformin, the most prominent of these diabetes drugs, has been called the "Drug of Miracles and Wonders," as clinical trials have found it to be beneficial for human patients suffering from these maladies. To promote viral replication in all infected human cells, SARS-CoV-2 stimulates the infected liver cells to produce glucose and to export it into the blood stream, which can cause diabetes in long COVID patients, and metformin, which reduces the levels of glucose in the blood, was shown to cut the incidence rate of long COVID in half for all patients recovering from SARS-CoV-2. Metformin leads to the phosphorylation of the AMP-activated protein kinase AMPK, which accelerates the import of glucose into cells via the glucose transporter GLUT4 and switches the cells to the starvation mode, counteracting the virus. Diabetes drugs also stimulate the unfolded protein response and thus mitophagy, which is beneficial for healthy aging and mental health. Diabetes drugs were also found to mimic exercise and help to reduce body weight.

The interplay of gut microbiota, obesity, and depression: insights and interventions

The gut microbiome, body weight, and related comorbidities are intricately linked through a complex interaction of microbial, genetic, environmental, and psychological factors. Alterations in gut microbiota can contribute to the development of weight disorders and depressive symptoms, with the potential for these relationships to be bidirectional. Effective management of these interconnected conditions often involves a combination of lifestyle modifications and psychological support. Medical interventions, including treatments for obesity, antidiabetic drugs, antidepressants, antibiotics, and probiotics, can have beneficial and detrimental effects on gut microbiota and mental health. Further research is needed to better understand their impact on gut microbiome and mental health in the context of obesity.

Meta-analysis of the human gut microbiome uncovers shared and distinct microbial signatures between diseases

Microbiome studies have revealed gut microbiota's potential impact on complex diseases. However, many studies often focus on one disease per cohort. We developed a meta-analysis workflow for gut microbiome profiles and analyzed shotgun metagenomic data covering 11 diseases. Using interpretable machine learning and differential abundance analysis, our findings reinforce the generalization of binary classifiers for Crohn's disease (CD) and colorectal cancer (CRC) to hold-out cohorts and highlight the key microbes driving these classifications. We identified high microbial similarity in disease pairs like CD vs ulcerative colitis (UC), CD vs CRC, Parkinson's disease vs type 2 diabetes (T2D), and schizophrenia vs T2D. We also found strong inverse correlations in Alzheimer's disease vs CD and UC. These findings, detected by our pipeline, provide valuable insights into these diseases.

IMPORTANCE

Assessing disease similarity is an essential initial step preceding a disease-based approach for drug repositioning. Our study provides a modest first step in underscoring the potential of integrating microbiome insights into the disease similarity assessment. Recent microbiome research has predominantly focused on analyzing individual diseases to understand their unique characteristics, which by design excludes comorbidities in individuals. We analyzed shotgun metagenomic data from existing studies and identified previously unknown similarities between diseases. Our research represents a pioneering effort that utilizes both interpretable machine learning and differential abundance analysis to assess microbial similarity between diseases.

Glucagon-Like Peptide-1 Receptor Agonists and Risk for Suicidal Ideation and Behaviors in U.S. Older Adults With Type 2 Diabetes : A Target Trial Emulation Study

BACKGROUND

A major concern has recently emerged about a potential link between glucagon-like peptide-1 receptor agonists (GLP-1 RAs) and increased risk for suicidal ideation and behaviors based on International Classification of Diseases codes.

OBJECTIVE

To investigate the association between GLP-1 RAs, compared with sodium-glucose cotransporter-2 inhibitors (SGLT2is) or dipeptidyl peptidase-4 inhibitors (DPP4is), and risk for suicidal ideation and behaviors in older adults with type 2 diabetes (T2D).

DESIGN

Two target trial emulation studies comparing propensity score (PS)-matched cohorts for GLP-1 RAs versus SGLT2is and GLP-1 RAs versus DPP4is.

SETTING

U.S. national Medicare administrative data from January 2017 to December 2020.

PATIENTS

Older adults (≥66 years) with T2D; no record of suicidal ideation or behaviors; and a first prescription for a GLP-1 RA, SGLT2i, or DPP4i.

MEASUREMENTS

The primary end point was a composite of suicidal ideation and behaviors. New GLP-1 RA users were matched 1:1 on PS to new users of an SGLT2i or DPP4i in each pairwise comparison. A Cox proportional hazards regression was used to estimate the hazard ratio (HR) and 95% CIs within matched groups.

RESULTS

This study included 21 807 pairs of patients treated with a GLP-1 RA versus an SGLT2i and 21 402 pairs of patients treated with a GLP-1 RA versus a DPP4i. The HR of suicidal ideation and behaviors associated with GLP-1 RAs relative to SGLT2is was 1.07 (95% CI, 0.80 to 1.45; rate difference, 0.16 [CI, -0.53 to 0.86] per 1000 person-years); the HR relative to DPP4is was 0.94 (CI, 0.71 to 1.24; rate difference, -0.18 [CI, -0.92 to 0.57] per 1000 person-years).

LIMITATIONS

Low event rate; imprecise estimates; unmeasured confounders, such as body mass index; and potential misclassification of outcomes.

CONCLUSION

Among Medicare beneficiaries with T2D, this study found no clear increased risk for suicidal ideation and behaviors with GLP-1 RAs, although estimates were imprecise and a modest adverse risk could not be ruled out.

PRIMARY FUNDING SOURCE

American Foundation for Pharmaceutical Education, Pharmaceutical Research and Manufacturers of America Foundation, National Institute on Aging, and National Institute of Diabetes and Digestive and Kidney Diseases.

Targeting GLP-1 receptors to reduce nicotine use disorder: Preclinical and clinical evidence

Nicotine use disorder (NUD) remains a leading cause of preventable death in the U.S. Unfortunately, current FDA-approved pharmacotherapies for smoking cessation have limited efficacy and are associated with high rates of relapse. One major barrier to long-term smoking abstinence is body weight gain during withdrawal. Nicotine withdrawal-induced body weight gain can also lead to development of chronic disease states like obesity and type II diabetes mellitus. Therefore, it is critical to identify novel pharmacotherapies for NUD that decrease relapse and nicotine withdrawal symptoms including body weight gain. Recent studies demonstrate that glucagon-like peptide-1 receptor (GLP-1R) agonists attenuate voluntary nicotine taking and seeking and prevent withdrawal-induced hyperphagia and body weight gain. Emerging evidence also suggests that GLP-1R agonists improve cognitive deficits, as well as depressive- and anxiety-like behaviors, which contribute to smoking relapse during withdrawal. While further studies are necessary to fully characterize the effects of GLP-1R agonists on NUD and understand the mechanisms by which GLP-1R agonists decrease nicotine withdrawal-mediated behaviors, the current literature supports GLP-1R-based approaches to treating NUD.

Cross-sectional, case-control and longitudinal associations between exposure to glucagon-like peptide-1 receptor agonists and the dispensing of antidepressants

AIM

To determine if the dispensing of glucagon-like peptide (GLP)-1 receptor agonists is associated with increased dispensing of antidepressants.

MATERIALS AND METHODS

We used cross-sectional, case-control and retrospective cohort study designs to examine the association between dispensed GLP-1 receptor agonists and antidepressants between 2012 and 2022 in the 10% random sample of the Australian Pharmaceutical Benefits Scheme (PBS) data. PBS-listed GLP-1 receptor agonists, exenatide, dulaglutide and semaglutide were the exposures. Outcomes were the odds ratio [ORs; 99% confidence interval (CI)] and hazard ratio (99% CI) of being dispensed any antidepressant. Analyses were adjusted for demographic measures and the dispensing of medicines to manage cardiovascular diseases or anxiety/insomnia. Statistical tests were two-sided at the 1% level of significance.

RESULTS

In total, 358 075 of 1 746 391 individuals were dispensed antidepressants, and 8495 of the 24 783 dispensed a GLP-1 receptor agonist were also dispensed an antidepressant in 2022 (OR 1.44; 99% CI 1.38-1.50); 24 103 of the 1 746 391 participants had been dispensed a GLP-1 receptor agonist between 2012 and 2021, and of these 8083 were dispensed antidepressants in 2022 (OR 1.52; 99% CI 1.46-1.59). The 2012 cohort included 1 213 316 individuals who had not been dispensed antidepressants that year. The hazard ratio of being dispensed an antidepressant between 2013 and 2022 following the dispensing of a GLP-1 receptor agonist was 1.19 (99% CI 1.12-1.27). Additional analyses restricting the time of exposure confirmed these associations for all PBS-listed GLP-1 receptor agonists.

CONCLUSIONS

Individuals exposed to GLP-1 receptor agonists are at greater risk of being dispensed antidepressants. The possible impact of GLP-1 receptor agonists on the mood of consumers requires ongoing vigilance and further research.

Investigating the Influence of Antidiabetic Medications and Psychosocial Factors

The relationship between type 2 diabetes mellitus (T2DM) and depression presents a significant area of medical concern, characterized by a higher incidence of depression among T2DM patients compared to the general population. This connection is not only evidenced in the prevalence of depressive symptoms in diabetic patients but also in the way these symptoms impact diabetes management. Furthermore, the influence of antidiabetic medications, especially sodium-glucose cotransporter-2 (SGLT2) inhibitors, on depression risk is a topic of ongoing research, with contrasting findings regarding the effects of drugs like metformin and pioglitazone. The aim of this study is to provide a comprehensive analysis of the relationship between T2DM and depression, focusing on the prevalence of depressive symptoms among diabetic patients, and the role of antidiabetic medications in modulating depression risk. Methods Utilizing data from the National Health and Nutrition Examination Survey (NHANES), we focused on individuals with T2DM. Depression status was assessed using the nine-item Patient Health Questionnaire (PHQ-9), a validated tool for evaluating depressive symptoms. Participants' depression status was categorized based on PHQ-9 composite scores. The analysis included demographic variables and the use of antidiabetic medications, with a focus on SGLT2 inhibitors. Logistic regression models adjusted for age, race/ethnicity, and BMI were employed. Results Our study involved 23,575 participants, of which 7,862 had T2DM. A significant difference in age and BMI was observed between diabetic and non-diabetic groups. Logistic regression analysis indicated that non-diabetic individuals had a significantly lower likelihood of depression compared to diabetic patients not on SGLT2 inhibitors. However, no statistically significant difference in depression levels was found between diabetic patients on SGLT2 inhibitors and those not on these medications. Conclusion These findings highlight the complex relationship between diabetes, antidiabetic medication, and depression. Notably, we found no significant impact of SGLT2 inhibitors on depression in diabetic patients, challenging previous assumptions about the role of specific antidiabetic drugs in mental health. We also revealed that older diabetic individuals reported fewer depressive symptoms, suggesting the influence of psychosocial factors and the need for age-specific depression management strategies. This research underscores the necessity of further studies to explore the nuanced effects of different antidiabetic medications on mental health outcomes, guiding toward more personalized treatment approaches for the mental health challenges in T2DM.

Differential Effects of Type 2 Diabetes Treatment Regimens on Diabetes Distress and Depressive Symptoms in the Glycemia Reduction Approaches in Diabetes: A Comparative Effectiveness Study (GRADE)

OBJECTIVE

We evaluated whether adding basal insulin to metformin in adults with early type 2 diabetes mellitus (T2DM) would increase emotional distress relative to other treatments.

RESEARCH DESIGN AND METHODS

The Glycemia Reduction Approaches in Diabetes: A Comparative Effectiveness Study (GRADE) of adults with T2DM of <10 years' duration, HbA1c 6.8-8.5%, and taking metformin monotherapy randomly assigned participants to add insulin glargine U-100, sulfonylurea glimepiride, the glucagon-like peptide-1 receptor agonist liraglutide, or the dipeptidyl peptidase 4 inhibitor sitagliptin. The Emotional Distress Substudy enrolled 1,739 GRADE participants (mean [SD] age 58.0 [10.2] years, 32% female, 56% non-Hispanic White, 18% non-Hispanic Black, 17% Hispanic) and assessed diabetes distress and depressive symptoms every 6 months. Analyses examined differences at 1 year and over the 3-year follow-up.

RESULTS

Across treatments, diabetes distress (-0.24, P < 0.0001) and depressive symptoms (-0.67, P < 0.0001) decreased over 1 year. Diabetes distress was lower at 1 year for the glargine group than for the other groups combined (-0.10, P = 0.002). Diabetes distress was also lower for liraglutide than for glimepiride or sitagliptin (-0.10, P = 0.008). Over the 3-year follow-up, there were no significant group differences in total diabetes distress; interpersonal diabetes distress remained lower for those assigned to liraglutide. No significant differences were observed for depressive symptoms.

CONCLUSIONS

Contrary to expectations, this randomized trial found no evidence for a deleterious effect of basal insulin on emotional distress. Glargine lowered diabetes distress modestly at 1 year rather than increasing it. Liraglutide also reduced diabetes distress at 1 year. Results can inform treatment decisions for adults with early T2DM.

Neurological and metabolic related pathophysiologies and treatment of comorbid diabetes with depression

BACKGROUND

The comorbidity between diabetes mellitus and depression was revealed, and diabetes mellitus increased the prevalence of depressive disorder, which ranked 13th in the leading causes of disability-adjusted life-years. Insulin resistance, which is common in diabetes mellitus, has increased the risk of depressive symptoms in both humans and animals. However, the mechanisms behind the comorbidity are multi-factorial and complicated. There is still no causal chain to explain the comorbidity exactly. Moreover, Selective serotonin reuptake inhibitors, insulin and metformin, which are recommended for treating diabetes mellitus-induced depression, were found to be a risk factor in some complications of diabetes.

AIMS

Given these problems, many researchers made remarkable efforts to analyze diabetes complicating depression from different aspects, including insulin resistance, stress and Hypothalamic-Pituitary-Adrenal axis, neurological system, oxidative stress, and inflammation. Drug therapy, such as Hydrogen Sulfide, Cannabidiol, Ascorbic Acid and Hesperidin, are conducive to alleviating diabetes mellitus and depression. Here, we reviewed the exact pathophysiology underlying the comorbidity between depressive disorder and diabetes mellitus and drug therapy.

METHODS

The review refers to the available literature in PubMed and Web of Science, searching critical terms related to diabetes mellitus, depression and drug therapy.

RESULTS

In this review, we found that brain structure and function, neurogenesis, brain-derived neurotrophic factor and glucose and lipid metabolism were involved in the pathophysiology of the comorbidity. Obesity might lead to diabetes mellitus and depression through reduced adiponectin and increased leptin and resistin. In addition, drug therapy displayed in this review could expand the region of potential therapy.

CONCLUSIONS

The review summarizes the mechanisms underlying the comorbidity. It also overviews drug therapy with anti-diabetic and anti-depressant effects.

Meta-analysis of the human gut microbiome uncovers shared and distinct microbial signatures between diseases

Microbiome studies have revealed gut microbiota's potential impact on complex diseases. However, many studies often focus on one disease per cohort. We developed a meta-analysis workflow for gut microbiome profiles and analyzed shotgun metagenomic data covering 11 diseases. Using interpretable machine learning and differential abundance analysis, our findings reinforce the generalization of binary classifiers for Crohn's disease (CD) and colorectal cancer (CRC) to hold-out cohorts and highlight the key microbes driving these classifications. We identified high microbial similarity in disease pairs like CD vs ulcerative colitis (UC), CD vs CRC, Parkinson's disease vs type 2 diabetes (T2D), and schizophrenia vs T2D. We also found strong inverse correlations in Alzheimer's disease vs CD and UC. These findings detected by our pipeline provide valuable insights into these diseases.

Metformin Improves Comorbid Depressive Symptoms in Mice with Allergic Rhinitis by Reducing Olfactory Bulb Damage

Allergic rhinitis (AR) is a widespread disease that is frequently comorbid with depression. However, the mechanisms and treatments for depression in AR remain underexplored. Metformin, a widely used antidiabetic drug, has shown antidepressant effects. The aim of this study was to explore the effects and potential mechanisms of metformin on depression-like behaviors in an AR mouse model. In the present study, mice were sensitized and challenged with ovalbumin (OVA) to induce AR. Results showed that mice with AR exhibited significant depression-like behavior which was attenuated by metformin. In addition, the levels of expression of synaptic plasticity markers (anti-microtubule-associated protein 2, synaptophysin, postsynaptic density protein 95), neurogenesis markers (doublecortin and Ki-67), and brain-derived neurotrophic factor were decreased in the olfactory bulb (OB) of mice with AR, while metformin ameliorated all these alterations and reduced apoptosis in the OB of these mice. Furthermore, it enhanced the phosphorylation of AMP-activated kinase (AMPK) and the levels of ten-eleven translocation 2 (TET2) and 5-hydroxymethylcytosine in the OB. In conclusion, our findings suggest that metformin might be a viable strategy for treating AR-related depression, possibly by modulating neuroplasticity, neurogenesis, apoptosis, and BDNF signaling in the OB via the AMPK/TET2 pathway.

TET2 deficiency promotes anxiety and depression-like behaviors by activating NLRP3/IL-1β pathway in microglia of allergic rhinitis mice

BACKGROUND

Anxiety and depression-like behaviors in allergic rhinitis (AR) are attracting attention, while the precise mechanism has not been clearly elucidated. Recent evidence shows that neuroinflammation in anterior cingulate cortex (ACC) may be the core of these neuropsychiatric symptoms in AR. Here, we investigated the molecular link between the anxiety and depression-like behaviors and neuroinflammation in ACC.

METHODS

Mice were sensitized and challenged with ovalbumin (OVA) to induce AR. Nasal inflammation levels were assessed by H&E staining and PAS staining. Anxiety and depression-like behaviors were evaluated by behavioral experiments including open field test, forced swimming test, and sucrose preference test. Neuronal impairment was characterized via Nissl staining and 18FDG-PET. The role of ten-eleven translocation 2 (TET2) in AR-related anxiety and depression was assessed by Tet2-/- mice. In addition, the murine BV2 microglial cell line was utilized to explore the molecular mechanisms by which TET2 mediates neuroinflammation. The levels of TET2, NLRP3 and their downstream molecules were detected by immunohistochemistry, Western blot, Dot blot and ELISA. The effects of metformin on depression-like behaviors in AR mice were also evaluated.

RESULTS

AR mice showed significant anxiety and depression-like behaviors, which associated with the activation of ACC. Loss of TET2 activated the NLRP3/IL-1β pathway of microglia in AR mice, further accelerating the anxiety and depression-like behaviors. In addition, knockdown of TET2 activated the NLRP3/IL-1β pathway in BV2 cells. Metformin improved the neuropsychiatric symptoms of AR mice by reducing the activation of NLRP3/IL-1β pathway after upregulating TET2.

CONCLUSION

TET2 deficiency activates the NLRP3/IL-1β pathway of microglia in the ACC, promoting the pathological process of anxiety and depression-like behavior in AR. Metformin could be effective in treating neuroinflammation by regulating microglia via TET2 up-regulation, indicating that metformin is a potential way to treat anxiety and depression-like behaviors in AR.

Effect of a religious coping intervention of rational emotive behavior therapy on mental health of adult learners with type II diabetes

BACKGROUND

Some previous studies have highlighted the high rate of mental health problems associated with type II diabetes (T2DM). The primary purpose of this study was to investigate the effect of a religious coping intervention of rational emotive behavior therapy (REBT) on the mental health of adult learners with T2DM.

METHODS

This study utilized a randomized controlled trial to select 146 adult learners with T2DM and mental health-related problems. The treatment group was made up of 73 adult learners, while the control group was also made up of 73 adult learners. The experimental group received 8 sessions of a religious coping intervention of REBT, while the control group received usual care. Data were collected using the patient health questionnaire, Warwick-Edinburgh mental well-being scale, and Kessler psychological distress scale. Repeated ANOVA and univariate analysis of covariance were used for data analyses.

RESULTS

The religious coping intervention of REBT substantially enhanced the mental health of adult learners with T2DM as measured by Warwick-Edinburgh mental well-being scale (P < .000) and patient health questionnaire (P < .000). The religious coping intervention of REBT significantly alleviated the psychological distress of adult learners with T2DM as measured by Kessler psychological distress scale (P < .000).

CONCLUSION

In this study, it has been demonstrated that a religious coping intervention of REBT effectively improves the mental health of adult learners with T2DM. The study concludes that the religious coping intervention of REBT is a practical alternative medicine approach to enhancing the mental health of adult learners with T2DM.

Anxiolytic effect of antidiabetic metformin is mediated by AMPK activation in mPFC inhibitory neurons

Diabetic patients receiving the antidiabetic drug metformin have been observed to exhibit a lower prevalence of anxiety disorders, yet the precise mechanism behind this phenomenon is unclear. In our study, we found that anxiety induces a region-specific reduction in AMPK activity in the medial prefrontal cortex (mPFC). Concurrently, transgenic mice with brain-specific AMPK knockout displayed abnormal anxiety-like behaviors. Treatment with metformin or the overexpression of AMPK restored normal AMPK activity in the mPFC and mitigated social stress-induced anxiety-like behaviors. Furthermore, the specific genetic deletion of AMPK in the mPFC not only instigated anxiety in mice but also nullified the anxiolytic effects of metformin. Brain slice recordings revealed that GABAergic excitation and the resulting inhibitory inputs to mPFC pyramidal neurons were selectively diminished in stressed mice. This reduction led to an excitation-inhibition imbalance, which was effectively reversed by metformin treatment or AMPK overexpression. Moreover, the genetic deletion of AMPK in the mPFC resulted in a similar defect in GABAergic inhibitory transmission and a consequent hypo-inhibition of mPFC pyramidal neurons. We also generated a mouse model with AMPK knockout specific to GABAergic neurons. The anxiety-like behaviors in this transgenic mouse demonstrated the unique role of AMPK in the GABAergic system in relation to anxiety. Therefore, our findings suggest that the activation of AMPK in mPFC inhibitory neurons underlies the anxiolytic effects of metformin, highlighting the potential of this primary antidiabetic drug as a therapeutic option for treating anxiety disorders.

Glucagon-like peptide 1 (GLP-1) receptor agonists as a protective factor for incident depression in patients with diabetes mellitus: A systematic review

Glucagon-like peptide 1 (GLP-1) receptor agonists are widely used for glycemic control in patients with diabetes mellitus (DM) and are primarily indicated for type 2 diabetes mellitus (T2DM). GLP-1 receptor agonists have also been shown to have neuroprotective and antidepressant properties. Replicated evidence suggests that individuals with DM are significantly more likely to develop depression. Herein, we aim to investigate whether GLP-1 receptor agonists can be used prophylactically on patients with DM to lower the risk of incident depression. We conducted a systematic search for English-language articles published on the PubMed/MEDLINE, Scopus, Embase, APA, PsycInfo, Ovid and Google Scholar databases from inception to June 6, 2022. Four retrospective observational studies were identified that evaluated the neuroprotective effects of GLP-1 receptor agonists on incident depression in patients with DM. We found mixed results with regards to lowering the risk of incident depression, with two studies demonstrating a significant reduction in risk and two studies showing no such effect. A single study found that dulaglutide may lower susceptibility to depression. Our results were limited by high interstudy heterogeneity, paucity of literature, and lack of controlled trials. While we did not find evidence of GLP-1 receptor agonists significantly lowering risk of incident depression in patients with DM, promising neuroprotective data presented in two of the included papers, specifically on dulaglutide where information is scarce, provide the impetus for further investigation. Future research should focus on better elucidating the neuroprotective potential of different classes and doses of GLP-1 receptor agonists using controlled trials.

Assessment of cognitive impairment and depressive signs in patients with type 2 diabetes treated with metformin from Southeast Mexico: A cross-sectional study

Multiple factors associate diabetes with cognitive impairment and depression. Antidiabetic drugs have reported antidepressant and pro-cognitive effects in diabetic and non-diabetic subjects. Antidepressant and pro-cognitive effects of metformin are reported in various studies; however, these effects are not consistent among researches. We designed a cross-sectional study. We recruited patients with T2D diagnosis from the Diabetes Clinic of the Regional Hospital of High Specialty "Dr. Gustavo A. Rovirosa Pérez" from January 2019 to May 2022. We included 431 subjects with T2D, 374 patients with metformin treatment and 57 subjects without metformin. These patients were on intensive therapies and had not a previous diagnosis of cognitive impairment or depression. We applied Mini-Mental State Examination (MMSE) to evaluate cognitive impairment, and Hamilton Depression Rating Scale (HAM-D) to assess depressive signs. Our sample had a mean age of 53.77 ± 13.43 years. Metformin users were 374 individuals, and 57 subjects didn't use metformin. MMSE found cognitive impairment in 8.3% (n = 31) of metformin users, and 14.8% (n = 8) of patients without metformin. HAM-D scale showed that 39.5% (n = 147) of patients with metformin had depression signs, subjects without metformin and depressive signs were 44.6% (n = 25). We found no differences between groups for cognitive impairment and depression grades. We did not find associations between metformin treatment, cognitive impairment measures and depression sign measures. However, chronic metformin treatment, insulin use, glycemic control and age could influence our results.

Effects of hypoglycaemic therapy on frailty: a multi-dimensional perspective

INTRODUCTION

The prevalence of diabetes is increasing in older people. With increasing age, frailty emerges as a new complication leading to disability. Frailty does not only include physical dysfunction but also involves negative impact on cognition and mood. Triad of impairments (TOI) is a new concept that includes physical frailty, dementia and depression to reflect the wider spectrum of frailty.

AREAS COVERED

Little is known about effects of hypoglycaemic agents on frailty syndrome. A literature search was performed on studies, which reported effects of hypoglycaemic agents on the component of the TOI.

EXPERT OPINION

It appears that most hypoglycaemic agents have some effects on frailty, although the results of clinical studies are inconsistent. Metformin seems to have a consistent and a positive effect on physical frailty. Its effects on cognitive function, however, are inconclusive but tend to be positive. Metformin appeared to improve depressive symptoms. Other agents such as incretins, thiazolidinediones, and sodium glucose transporter-2 inhibitors have some positive effects on cognition and depression. Sulfonylureas, glinides, or insulin have either negative or neutral effects on TOI components. The negative effects of insulin could be partially explained by the negative psychological factors and the frequent episodes of hypoglycemia associated with such therapy.

Association of metformin and depression in patients with type 2 diabetes

BACKGROUND

Emerging evidence showed metformin may have pleiotropic effects on ameliorating depression. However, whether metformin was associated with decreased risk of depression remains unclear.

METHODS

A historical cohort study was conducted based on a medical claim database from 2010 to 2017 in Beijing, China. Patients newly diagnosed with T2D were classified into the metformin and non-metformin groups according to their initial antidiabetic prescription. The incidences of depression between the groups were compared using Cox proportional regression model.

RESULTS

There were 193,624 (37.4 %) and 323,930 (62.6 %) T2D patients in the metformin and non-metformin groups. The mean age was 54.9 (SD: 13.1) years and 53.9% were females. With a median follow-up of 3.2 years, 64,963 patients developed depression. The adjusted incidence of depression in the metformin group (30.6, 95 % CI: 30.1, 31.0 per 1000 person-years) was significantly lower than in the non-metformin group (39.6, 95 % CI: 39.3, 40.0 per 1000 person-years, P < 0.001). The metformin group was significantly associated with a lower risk of depression compared with the overall non-metformin group (HR: 0.77, 95% CI: 0.75, 0.78), as well as compared with α-glucosidase inhibitors (HR: 0.73, 95 % CI: 0.71, 0.74), sulfonylureas (HR: 0.84, 95 % CI: 0.82, 0.86), and glinides (HR: 0.85, 95 % CI: 0.82, 0.88), except for thiazolidinediones (HR: 0.96, 95 % CI: 0.91, 1.01). The association between metformin and lower depression risk was significant in all the age and sex subgroups.

CONCLUSIONS

Metformin was associated with a lower risk of depression compared with other oral hypoglycemic agents, indicating a potential pleiotropic effect on depression.

The role of metformin as a treatment for neuropsychiatric illness

Advances in psychopharmacology have been significantly slower to evolve than in other disciplines of medicine and therefore investigation into novel therapeutic approaches is required. Additionally, concurrent metabolic conditions are prevalent among people with mental disorders. Metformin is a widely used hypoglycaemic agent that is now being studied for use beyond diabetes management. Evidence is emerging that metformin has multiple effects on diverse neurobiological pathways and consequently may be repurposed for treating mental illness. Metformin may have beneficial neuroimmunological, neuroplastic, neuro-oxidative and neuro-nitrosative effects across a range of psychiatric and neurodegenerative illnesses. Mechanisms include glucose lowering effects and effects on AMP-activated protein kinase (AMPK) signalling, however the best evidence for clinical benefit is through the glucose lowering effects, with other mechanisms less supported by the current evidence base. This narrative review aims to draw together the existing evidence for use of metformin as a psychopharmaceutical and present the role of metformin in the context of physical and psychiatric ill health, including metabolic, endocrinological and cancer domains. It not only has therapeutic potential in medical comorbidity but may have potential in core illness domains.

Actions of Metformin in the Brain: A New Perspective of Metformin Treatments in Related Neurological Disorders

Metformin is a first-line drug for treating type 2 diabetes mellitus (T2DM) and one of the most commonly prescribed drugs in the world. Besides its hypoglycemic effects, metformin also can improve cognitive or mood functions in some T2DM patients; moreover, it has been reported that metformin exerts beneficial effects on many neurological disorders, including major depressive disorder (MDD), Alzheimer’s disease (AD) and Fragile X syndrome (FXS); however, the mechanism underlying metformin in the brain is not fully understood. Neurotransmission between neurons is fundamental for brain functions, and its defects have been implicated in many neurological disorders. Recent studies suggest that metformin appears not only to regulate synaptic transmission or plasticity in pathological conditions but also to regulate the balance of excitation and inhibition (E/I balance) in neural networks. In this review, we focused on and reviewed the roles of metformin in brain functions and related neurological disorders, which would give us a deeper understanding of the actions of metformin in the brain.

Associations of Cardiovascular Agents and Metformin with Depression Symptoms: A Cross-Sectional Analysis from the HUNT Study, Norway

BACKGROUND

Cardiovascular agents, including angiotensin-converting enzyme inhibitors, angiotensin II receptor inhibitors, acetylsalicylic acid, statins, and metformin, have demonstrated benefits for depression. However, there is scant evaluation of these drugs' antidepressant properties in large population settings.

OBJECTIVE

This study aimed to examine cross-sectional associations between depression symptoms and the use of cardiovascular agents and metformin in populations with cardiovascular diseases or diabetes mellitus.

METHODS

Participants in the Trøndelag Health Study 2006-08 (HUNT3, n = 40,516) and 2017-19 (HUNT4, n = 42,103) were included and data on their drug use from 2006 to 2019 was retrieved from the Norwegian Prescription Database. The outcome was self-reported depression symptoms defined by the Hospital Anxiety and Depression Scale. Associations between cardiovascular agents or metformin use and self-reported depression were analyzed by multi-level logistic regression in sex-stratified samples.

RESULTS

Among men with cardiovascular diseases, use of acetylsalicylic acid was associated with reduced depression symptoms compared with acetylsalicylic acid non-users (reference) in HUNT3 and HUNT4 [risk ratio = 0.76; 95% confidence interval 0.59-0.94, risk ratio = 0.67; 95% CI 0.52-0.82, respectively]. Similarly, male statin users had a lower likelihood of reporting depression than statin non-users in HUNT3 (risk ratio = 0.70; 95% confidence interval 0.54-0.86) and HUNT4 (risk ratio = 0.67; 95% confidence interval 0.51-0.84). Associations between statins or acetylsalicylic acid use and reduced depression symptoms were detected in women with cardiovascular diseases in HUNT4. We found no statistical support for associations between other cardiovascular agents or metformin use and a reduced or increased depression symptom risk.

CONCLUSIONS

Results suggest negative associations between acetylsalicylic acid or statin use and depression symptoms. However, longitudinal cohort studies and randomized controlled trials are required to confirm the antidepressant effects of these drugs.

7,8-Dihydroxyflavone and Neuropsychiatric Disorders: A Translational Perspective from the Mechanism to Drug Development

7,8-Dihydroxyflavone (7,8-DHF) is a kind of natural flavonoid with the potential to cross the blood-brain barrier. 7,8-DHF effectively mimics the effect of brain-derived neurotrophic factor (BDNF) in the brain to selectively activate tyrosine kinase receptor B (TrkB) and downstream signaling pathways, thus playing a neuroprotective role. The preclinical effects of 7,8-DHF have been widely investigated in neuropsychiatric disorders, including Alzheimer's disease (AD), Parkinson's disease (PD), depression, and memory impairment. Besides the effect on TrkB, 7,8-DHF could also function through fighting against oxidative stress, cooperating with estrogen receptors, or regulating intestinal flora. This review focuses on the recent experimental studies on depression, neurodegenerative diseases, and learning and memory functions. Additionally, the structural modification and preparation of 7,8-DHF were also concluded and proposed, hoping to provide a reference for the follow-up research and clinical drug development of 7,8-DHF in the field of neuropsychiatric disorders.

Associations Between DNA Methylation Age Acceleration, Depressive Symptoms, and Cardiometabolic Traits in African American Mothers From the InterGEN Study

Background

African American women (AAW) have a high risk of both cardiometabolic (CM) illness and depressive symptoms. Depressive symptoms co-occur in individuals with CM illness at higher rates than the general population, and accelerated aging may explain this. In this secondary analysis, we examined associations between age acceleration; depressive symptoms; and CM traits (hypertension, diabetes mellitus [DM], and obesity) in a cohort of AAW.

Methods

Genomic and clinical data from the InterGEN cohort (n = 227) were used. Age acceleration was based on the Horvath method of DNA methylation (DNAm) age estimation. Accordingly, DNAm age acceleration (DNAm AA) was defined as the residuals from a linear regression of DNAm age on chronological age. Spearman's correlations, linear and logistic regression examined associations between DNAm AA, depressive symptoms, and CM traits.

Results

DNAm AA did not associate with total depressive symptom scores. DNAm AA correlated with specific symptoms including self-disgust/self-hate (-0.13, 95% CI -0.26, -0.01); difficulty with making decisions (-0.15, 95% CI -0.28, -0.02); and worry over physical health (0.15, 95% CI 0.02, 0.28), but were not statistically significant after multiple comparison correction. DNAm AA associated with obesity (0.08, 95% CI 1.02, 1.16), hypertension (0.08, 95% CI 1.01, 1.17), and DM (0.20, 95% CI 1.09, 1.40), after adjustment for potential confounders.

Conclusions

Associations between age acceleration and depressive symptoms may be highly nuanced and dependent on study design contexts. Factors other than age acceleration may explain the connection between depressive symptoms and CM traits. AAW with CM traits may be at increased risk of accelerated aging.

Diabetes, antidiabetic medications and risk of depression - A population-based cohort and nested case-control study

OBJECTIVE

Diabetes type 2 is associated with depression, but the impact of antidiabetic drugs is not clear. The objective was to analyze the association between diabetes type 2, antidiabetic drugs, and depression.

METHODS

This register-based study included 116.699 patients with diabetes type 2 diagnosed from 2000 to 2012 and an age, gender, and municipality matched reference group of 116.008 individuals without diabetes. All participants were followed for a diagnosis of depression or prescription of antidepressant medication. Based on this, a case-control study was nested within the cohort, using risk set sampling. Antidiabetic medication was categorized into insulin, metformin, sulfonylureas and glinides combined, glitazones, dipeptidyl peptidase 4 (DPP4) inhibitors, glucagon-like peptide 1 (GLP1) analogs, sodium-glucose transport protein 2 (SGLT2) inhibitors and acarbose. The association between diabetes and depression was analyzed using Cox proportional hazards regression, whereas conditional logistic regression was used to analyze the association between use of antidiabetic drugs and depression.

RESULTS

Patients with diabetes had higher risk of depression compared to individuals without diabetes (hazard ratio 1.14 (95% confidence interval 1.14-1.15)). Low doses of metformin, DPP4 inhibitors, GLP1 analogs, and SGLT2 inhibitors were associated with lower risk of depression in patients with diabetes compared to non-users, with the lowest risk for sodium-glucose transport protein 2 inhibitor users (odds ratio 0.55 (0.44-0.70)). Use of insulin, sulfonylurea and high doses of metformin were associated with higher risk of depression.

CONCLUSION

Patients with diabetes had increased risk of depression. However, users of specific antidiabetic drugs had lower risk of depression compared to non-users.

Focal points of preanesthesia evaluations for electroconvulsive therapy in patients with depression: a retrospective analysis of clinical characteristics in nonremission

Background

This study explored the patient clinical characteristics that may affect electroconvulsive therapy (ECT) efficacy to enable improved focus during evaluations and preparation for ECT.

Methods

Patients were enrolled for ECT at the Department of Psychiatry and Anesthesiology of the First Affiliated Hospital of Chongqing Medical University from December 2017 to January 2019. The primary outcome in our study was defined as the development of nonremission. A multivariate logistic analysis was performed to identify the risk factors for nonremission.

Results

In total, 874 depressed patients were included in the study. After the ECT treatment, 255 cases (29.2%) exhibited nonremission. A multivariate logistic regression analysis of the variables was performed, and the results showed that atherosclerosis (OR 8.072, 95% CI 2.442 to 16.675; P = 0.001), COPD (OR 2.919, 95% CI 1.240 to 6.871; P = 0.014), diabetes (OR 2.202, 95% CI 1.115 to 4.348; P = 0.023) and smoking (OR 1.519, 95% CI 1.015 to 2.273; P = 0.042) were independent risk factors for nonremission.

Conclusion

In the retrospective analysis, we found that atherosclerosis, diabetes, COPD and smoking may be high-risk factors for nonremission.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12871-022-01686-6.

Comorbidity of Type 2 Diabetes Mellitus and Depression: Clinical Evidence and Rationale for the Exacerbation of Cardiovascular Disease

Depression is a common comorbidity of type 2 diabetes mellitus (T2DM). T2DM with comorbid depression increases the risk of cardiovascular events and death. Depression and T2DM and its macrovascular complications exhibited a two-way relationship. Regarding treatment, antidepressants can affect the development of T2DM and cardiovascular events, and hypoglycemic drugs can also affect the development of depression and cardiovascular events. The combination of these two types of medications may increase the risk of the first myocardial infarction. Herein, we review the latest research progress in the exacerbation of cardiovascular disease due to T2DM with comorbid depression and provide a rationale and an outlook for the prevention and treatment of cardiovascular disease in T2DM with comorbid depression.

Nanotechnology-Abetted Astaxanthin Formulations in Multimodel Therapeutic and Biomedical Applications

Astaxanthin (AXT) is one of the most important fat-soluble carotenoids that have abundant and diverse therapeutic applications namely in liver disease, cardiovascular disease, cancer treatment, protection of the nervous system, protection of the skin and eyes against UV radiation, and boosting the immune system. However, due to its intrinsic reactivity, it is chemically unstable, and therefore, the design and production processes for this compound need to be precisely formulated. Nanoencapsulation is widely applied to protect AXT against degradation during digestion and storage, thus improving its physicochemical properties and therapeutic effects. Nanocarriers are delivery systems with many advantages─ease of surface modification, biocompatibility, and targeted drug delivery and release. This review discusses the technological advancement in nanocarriers for the delivery of AXT through the brain, eyes, and skin, with emphasis on the benefits, limitations, and efficiency in practice.

Cognition, motor symptoms, and glycolipid metabolism in Parkinson's disease with depressive symptoms

Depressive symptoms and abnormal glycolipid metabolisms are common in patients with Parkinson's disease (PD), but their relationship has not been fully reported. It is not clear whether glycolipid impairments lead to poor cognitive and motor function, and aggravate depressive symptoms. Therefore, we aimed to explore the relationships between glycolipid variables, cognition, motor and depressive symptoms in PD patients cross-sectionally. Two hundred ten PD patients were recruited. Glycolipid parameters and Uric acid (UA) were measured. Depressive symptoms, cognitive function and motor symptoms were assessed using the Hamilton Depression Rating Scale-17 (HAMD-17), the Montreal Cognitive Assessment (MOCA) and the Movement Disorder Society Unified Parkinson's Disease Rating Scale Part-III (UPDRS-III). Depressive PD patients had significantly worse motor symptoms and higher levels of fasting plasma glucose (FPG) than those in non-depressive patients (F = 24.145, P < 0.001). Further, logistic regression analysis indicated that UPDRS-III (OR = 1.039, 95% CI 1.019-1.057, P = 0.044), FPG (OR = 1.447, 95% CI 1.050-1.994, P = 0.024) were independently associated with depression. In PD patients without depression, UA (β = - 0.068, t = - 2.913, P = 0.005) and cholesterol (CHOL) (β = - 3.941, t = - 2.518, P = 0.014) were independent predictors of the UPDRS-III score; in addition, UPDRS-III score was negatively associated with MOCA score (β = - 0.092, t = - 2.791, P = 0.007). FPG levels and motor symptoms were related to depressive symptoms in PD patients. Further, in non-depressive PD patients, UA and CHOL showed putative biomarkers of motor symptoms.

Elevated lipids are associated with reduced regional brain structure in youth with bipolar disorder

OBJECTIVE

Abnormal blood lipid levels are common in bipolar disorder (BD) and correlate with mood symptoms and neurocognition. However, studies have not examined the lipid-brain structure association in BD or youth.

METHODS

This study examined low-density lipoprotein (LDL-C), high-density lipoprotein (HDL-C), triglycerides, and total cholesterol (TC) levels in relation to brain structure utilizing T1-weighted images, among participants ages 13-20 with BD (n = 55) and healthy controls (HC; n = 47). General linear models investigated group differences in the association of lipids with anterior cingulate cortex (ACC), hippocampus, and inferior parietal lobe structure, controlling for age, sex, body mass index, and intracranial volume. For significant associations, post hoc within-group analyses were undertaken. Exploratory vertex-wise analyses further investigated group differences in the lipid-brain structure association.

RESULTS

There were significant group differences in the association of LDL-C (β = -0.29 p = 0.001), and TC (β = -0.21 p = 0.016), with hippocampal volume, and triglycerides with ACC volume (β = -0.25 p = 0.01) and area (β = -0.26 p = 0.004). Elevated lipids were associated with smaller brain structure to a significantly greater extent in BD vs HC. Post hoc analyses revealed that elevated LDL-C (β = -0.27 p = 0.007) and reduced HDL-C (β = 0.24 p = 0.01) were associated with smaller hippocampal volume in the BD group. Exclusion of BD second-generation antipsychotic users did not alter these results. Vertex-wise analyses further showed that elevated lipids were associated with smaller brain structure to a significantly greater extent in BD vs HC, across the cortex.

CONCLUSION

Elevated lipids are associated with smaller brain structure in BD. Research evaluating lipid-brain structure associations prospectively and whether lipid optimization has salutary effects on brain structure is necessary.

High Bodyweight Variability Increases Depression Risk in Patients With Type 2 Diabetes Mellitus: A Nationwide Cohort Study in Korea

Objectives: Although obesity is associated with increased risk for depression in patients with type 2 diabetes mellitus (DM), the relationship between body weight variability (BWV) and depression remains poorly studied. This study was to investigate the incidence of depression in patients with type 2 DM according to their BWV. Methods: Intraindividual variation in body weight were measured in the nationwide, population-based retrospective cohort of 540,293 patients with type 2 DM from the Korean national health insurance system between 2009 and 2010. The diagnoses of new-onset depression occurring until the end of 2017 were ascertained. Risk of new-onset depression was examined using multivariate-adjusted Cox proportional hazards regression analysis by BWV quartile. Results: 93,149 (17.2%) patients developed new-onset depression for the follow up. BWV was significantly associated with an increased risk of depression after adjusting for confounding factors. The highest BWV quartile group had a hazard ratio (HR) of 1.17 (95% CI 1.15-1.19) compared to the lowest BWV quartile group as a reference. Obese patients in the highest BWV quartile group showed 12% increased risk of depression (HR 1.12, 95% CI 1.09-1.15) while non-obese patients in the highest BWV quartile group showed 20% increased risk of depression (HR: 1.20, 95% CI: 1.17-1.23) compared to their respective lowest BWV quartile groups. Conclusion: A higher BWV was significantly associated with an increased risk of depression in patients with type 2 DM. Thus, BWV may serve as an indicator for early detection of depression in type 2 DM patients.

Antihypertensive Drugs and Risk of Depression: A Nationwide Population-Based Study

Hypertension, cardiovascular diseases, and cerebrovascular diseases are associated with an increased risk of depression, but it remains unclear whether treatment with antihypertensive agents decreases or increases this risk. The effects of individual drugs are also unknown. We used Danish population-based registers to systematically investigate whether the 41 most used individual antihypertensive drugs were associated with an altered risk of incident depression. Analyses of diuretics were included for comparisons. Participants were included in the study in January 2005 and followed until December 2015. Two different outcome measures were included: (1) a diagnosis of depressive disorder at a psychiatric hospital as an inpatient or outpatient and (2) a combined measure of a diagnosis of depression or use of antidepressants. Continued use of classes of angiotensin agents, calcium antagonists, and β-blockers was associated with significantly decreased rates of depression, whereas diuretic use was not. Individual drugs associated with decreased depression included 2 of 16 angiotensin agents: enalapril and ramipril; 3 of 10 calcium antagonists: amlodipine, verapamil, and verapamil combinations; and 4 of 15 β-blockers: propranolol, atenolol, bisoprolol, and carvedilol. No drug was associated with an increased risk of depression. In conclusion, real-life population-based data suggest a positive effect of continued use of 9 individual antihypertensive agents. This evidence should be used in guiding prescriptions for patients at risk of developing depression including those with prior depression or anxiety and patients with a family history of depression.