Copper Concentrations in Ketamine Therapy for Treatment-Resistant Depression

The Role of Copper Overload in Modulating Neuropsychiatric Symptoms

Copper is a transition metal essential for growth and development and indispensable for eukaryotic life. This metal is essential to neuronal function: its deficiency, as well as its overload have been associated with multiple neurodegenerative disorders such as Alzheimer's disease and Wilson's disease and psychiatric conditions such as schizophrenia, bipolar disorder, and major depressive disorders. Copper plays a fundamental role in the development and function of the human Central Nervous System (CNS), being a cofactor of multiple enzymes that play a key role in physiology during development. In this context, we thought it would be timely to summarize data on alterations in the metabolism of copper at the CNS level that might influence the development of neuropsychiatric symptoms. We present a non-systematic review with the study selection based on the authors' judgement to offer the reader a perspective on the most significant elements of neuropsychiatric symptoms in Wilson's disease. We highlight that Wilson's disease is characterized by marked heterogeneity in clinical presentation among patients with the same mutation. This should motivate more research efforts to disentangle the role of environmental factors in modulating the expression of genetic predisposition to this disorder.

Treatment-Resistant Depression in Real-World Clinical Practice: A Systematic Literature Review of Data from 2012 to 2022

OBJECTIVE

Real-world evidence in treatment-resistant depression (TRD; commonly defined as non-response to ≥ 2 consecutive treatments at adequate dosage and duration) is lacking. A systematic literature review was conducted to understand disease burden and treatment outcomes for patients with TRD, studied in a real-world setting over the last decade.

DATA SOURCES

A literature search was conducted in May 2022 in MEDLINE, Embase, The Cochrane Libraries and PsycINFO, comprising studies published from 2012 to 2022. Bibliographies of all relevant identified systematic reviews and relevant conference proceedings from 2020 to 2022 were manually hand-searched.

STUDY SELECTION

Real-world studies, including cohort, cross-sectional, case-control, chart review and registry studies, published in English and reporting outcomes in adults with TRD, were included.

DATA EXTRACTION

Extracted data included study and baseline disease characteristics, treatment type, treatment response, clinical outcomes and health-related quality of life.

RESULTS

Twenty studies were included. Criteria for TRD varied, but patients typically experienced long-lasting depression (range 1.4 to 16.5 years). Across studies, mean disease severity scores demonstrated moderate to severe depression, reflecting a high burden of disease at baseline. Remission rates were typically low but generally increased with longer follow-up durations. However, the heterogeneity of interventions, follow-up durations (range 2 weeks to 9.4 years) and assessment tools precluded their quantitative synthesis. Studies were frequently limited by low sample size (range 14 to 411 patients) and health-related quality of life was infrequently assessed.

CONCLUSIONS

There is a lack of clinical consensus regarding the definition, assessment and monitoring of TRD in real-world practice. Nevertheless, TRD carries a high burden of illness and there is an unmet need for faster and more effective treatments. To better understand the personal burden of affected patients, future studies would benefit from standardisation of severity assessment and measures of treatment effectiveness, as well as greater consideration of health-related quality of life.

Major Depressive Disorder in an International Multisite Wilson Disease Registry

BACKGROUND AND AIMS

Psychiatric symptoms are frequently reported in Wilson disease (WD); however, systematic assessments with validated measures are lacking.

OBJECTIVE

We aim to report the prevalence and clinical correlates for major depressive disorder (MDD) as resulting from a multisite international WD registry.

METHODS

All patients enrolled in the WD registry received structured psychiatric evaluations (Mini International Neuropsychiatric Interview, Patient Health Questionnaire-9, Generalized Anxiety Disorder-7 scale, Perceived Stress Scale), laboratory tests, hepatology, and neurological assessments. We present the analysis of the data collected at enrollment for the first 3 years (N = 62).

RESULTS

Thirty-seven percent (23) had a lifetime history (MDD), and 6% (4) met the criteria for an active major depressive episode. Depression was self-reported in 30.51% (19) at WD diagnosis. Patients with MDD had worse mental health quality-of-life (QOL) scores (median 43 vs 53.6, P = 0.006), higher severe anxiety (13.04% vs 0), higher perceived stress (median 18 vs 9, P < 0.003), and higher levels of neuroticism (median 8 vs 5.0, P = 0.002). We found no significant difference in physical health QOL and severity of neurological or liver disease. There was no significant difference in copper parameters or liver tests in those with MDD and without. The limitations of our study consist of the small sample size, the cross-sectional report, and the lack of brain copper measurements.

CONCLUSIONS

Lifetime MDD is highly prevalent in WD and associated with worse mental health QOL. We did not find a significant association among liver disease, neurological disease laboratory tests, and MDD. Screening for depression should be considered in patients with WD.

BMI Modifies the Association Between Depression Symptoms and Serum Copper Levels

Depression is one of the most common mental disorders which dramatically threatens public health and wellness. Copper has been known to be involved in many biological processes that could help explaining the occurrence of depression. However, studies focusing on its effect have yielded mixed results. The present study aims to evaluate the association between serum copper levels and depression symptoms. It also investigates the effect of modification of BMI (body mass index) on depression symptoms. A total of 5419 US adults aged 20 years or older from the National Health and Nutrition Examination Survey (NHANES) 2011-2016 participated in the cross-sectional study. Logistic regression models were applied using depression levels as the outcome and serum cooper/selenium/zinc categories as the main predictor, with the adjustments of gender, age, marital status, race, education, family income level, alcohol drinking, cigarette smoking, diabetes, pressure, stroke, and BMI. The interaction terms for copper levels and other covariates were further incorporated into the model to assess their roles in predicting depression symptoms. The prevalence of depression symptoms was significantly higher in samples with a high copper level. Among the levels of serum copper, selenium, and zinc, only the association between depression symptoms and serum copper levels was observed to be significant in the unadjusted model (P = 0.002). Individuals with a high copper level (114-134 μg/dL) and a very high copper level (≥ 134 μg/dL) had 1.85 (95% CI 1.24, 2.77)- and 1.72 (95% CI 1.21, 2.44)-fold higher odds ratio of depression symptoms, respectively, compared to those with a normal serum copper level. Although the association was not significant in the adjusted models, in which confounders were added, the interaction of copper level, including high and very high copper levels, and obesity (BMI ≥ 30 kg/m²) exhibited significantly higher odds ratio (4.12 (95% CI 1.38, 12.27) and 4.53 (95% CI 1.87, 10.96)) of having depression symptoms. The concentration of serum copper was positively associated with the prevalence of depression symptoms. Obesity exacerbated the risk of having depression symptoms in people with high serum copper levels.

Blood-based biomarkers of antidepressant response to ketamine and esketamine: A systematic review and meta-analysis

(R,S)-ketamine (ketamine) and its enantiomer (S)-ketamine (esketamine) can produce rapid and substantial antidepressant effects. However, individual response to ketamine/esketamine is variable, and there are no well-accepted methods to differentiate persons who are more likely to benefit. Numerous potential peripheral biomarkers have been reported, but their current utility is unclear. We conducted a systematic review/meta-analysis examining the association between baseline levels and longitudinal changes in blood-based biomarkers, and response to ketamine/esketamine. Of the 5611 citations identified, 56 manuscripts were included (N = 2801 participants), and 26 were compatible with meta-analytical calculations. Random-effect models were used, and effect sizes were reported as standardized mean differences (SMD). Our assessments revealed that more than 460 individual biomarkers were examined. Frequently studied groups included neurotrophic factors (n = 15), levels of ketamine and ketamine metabolites (n = 13), and inflammatory markers (n = 12). There were no consistent associations between baseline levels of blood-based biomarkers, and response to ketamine. However, in a longitudinal analysis, ketamine responders had statistically significant increases in brain-derived neurotrophic factor (BDNF) when compared to pre-treatment levels (SMD [95% CI] = 0.26 [0.03, 0.48], p = 0.02), whereas non-responders showed no significant changes in BDNF levels (SMD [95% CI] = 0.05 [-0.19, 0.28], p = 0.70). There was no consistent evidence to support any additional longitudinal biomarkers. Findings were inconclusive for esketamine due to the small number of studies (n = 2). Despite a diverse and substantial literature, there is limited evidence that blood-based biomarkers are associated with response to ketamine, and no current evidence of clinical utility.

Interaction of Serum Copper and Neurometabolites on Executive Dysfunction in Unmedicated Patients With Major Depressive Disorder

Objective: The mechanism of executive function (EF) impairment in major depressive disorder (MDD) remains unclear. Previous studies have demonstrated that altered serum copper levels and neurometabolic alterations may be associated with the psychopathology and cognitive impairment of MDD. While, their inter-relationships in MDD remain uncertain. The present study aims to assess whether the interaction between serum copper levels and neurometabolic alterations is involved in the deficit of executive function (EF) in patients with unmedicated MDD. Methods: Serum copper levels and EFs were measured in 41 MDD patients and 50 control subjects. EFs were evaluated by Trail Making Test, Part-B (TMT-B), Digit Symbol Substitution Test (DSST), Wisconsin Card Sorting Task (WCST), and Semantic Verbal Fluency testing (SVFT). Additionally, 41 patients and 41 healthy controls underwent proton magnetic resonance spectroscopy (¹H-MRS) to obtain ratios of N-acetyl aspartate to creatine (NAA/Cr) and choline-containing compounds to creatine (Cho/Cr) in the lenticular nucleus (LN) of basal ganglia (BG). Finally, association and interaction analysis were conducted to investigate their inter-relationships. Results: The results showed that patients performed worse in the DSST, WCST, TMT-B time and SVFT. Moreover, patients had higher serum copper levels, but lower NAA/Cr ratios in left LN of BG than healthy controls. In patients, serum copper levels were found to significantly negative associated with Categories Completed (CC) number of WCST (r = -0.408, p = 0.008), and positive associated with the Total Errors (TE) and Nonperseverative Errors (PE) number of WCST (r = 0.356, p = 0.023; r = -0.356, p = 0.022). In addition, the NAA/Cr ratios of left LN were found to significantly negative associated with VFS (r = -0.401, p = 0.009), as well as negative associated with serum copper levels (r = -0.365, p = 0.019). Finally, the interaction between copper and NAA may as influencing factors for SVFT and CC number of WCST in patients. Conclusion: Our results indicated that the interaction of abnormal copper levels and NAA/Cr neurometabolic disruption of the LN may impact executive dysfunction, and this may relevant to the pathophysiology of executive impairment in MDD patients.