Provider Perspectives on the Current Use of Lithium Medications and Lithium Monitoring Practices for Psychiatric Conditions

Therapeutic Drug Monitoring in Psychiatry: Enhancing Treatment Precision and Patient Outcomes

Psychiatric disorders often require pharmacological interventions to alleviate symptoms and improve quality of life. However, achieving an optimal therapeutic outcome is challenging due to several factors, including variability in the individual response, inter-individual differences in drug metabolism, and drug interactions in polytherapy. Therapeutic drug monitoring (TDM), by measuring drug concentrations in biological samples, represents a valuable tool to address these challenges, by tailoring medication regimens to each individual. This review analyzes the current landscape of TDM in psychiatric practice, highlighting its significance in optimizing drug dosages, minimizing adverse effects, and improving therapeutic efficacy. The metabolism of psychiatric medications (i.e., mood stabilizers, antipsychotics, antidepressants) often exhibits significant inter-patient variability. TDM can help address this variability by enhancing treatment personalization, facilitating early suboptimal- or toxic-level detection, and allowing for timely interventions to prevent treatment failure or adverse effects. Furthermore, this review briefly discusses technological advancements and analytical methods supporting the implementation of TDM in psychiatric settings. These innovations enable quick and cost-effective drug concentration measurements, fostering the widespread adoption of TDM as a routine practice in psychiatric care. In conclusion, the integration of TDM in psychiatry can improve treatment outcomes by individualizing medication regimens within the so-called precision medicine.

Therapeutic Potential Effect of Glycogen Synthase Kinase 3 Beta (GSK-3β) Inhibitors in Parkinson Disease: Exploring an Overlooked Avenue

Parkinson's disease (PD) is a progressive neurodegenerative disease of the brain due to degeneration of dopaminergic neurons in the substantia nigra (SN). Glycogen synthase kinase 3 beta (GSK-3β) is implicated in the pathogenesis of PD. Therefore, the purpose of the present review was to revise the mechanistic role of GSK-3β in PD neuropathology, and how GSK-3β inhibitors affect PD neuropathology. GSK-3 is a conserved threonine/serine kinase protein that is intricate in the regulation of cellular anabolic and catabolic pathways by modulating glycogen synthase. Over-expression of GSK-3β is also interconnected with the development of different neurodegenerative diseases. However, the underlying mechanism of GSK-3β in PD neuropathology is not fully clarified. Over-expression of GSK-3β induces the development of PD by triggering mitochondrial dysfunction and oxidative stress in the dopaminergic neurons of the SN. NF-κB and NLRP3 inflammasome are activated in response to dysregulated GSK-3β in PD leading to progressive neuronal injury. Higher expression of GSK-3β in the early stages of PD neuropathology might contribute to the reduction of neuroprotective brain-derived neurotrophic factor (BDNF). Thus, GSK-3β inhibitors may be effective in PD by reducing inflammatory and oxidative stress disorders which are associated with degeneration of dopaminergic in the SN.

Rapid Detection of Lithium Concentrations in Oral Fluid

BACKGROUND

Lithium medication is considered to be the first-line treatment for bipolar disorder as a monotherapy, and for treatment-resistant depression with lithium augmentation. However, because of potential toxicity, lithium levels must be monitored frequently. Recent studies have demonstrated a significant correlation between lithium levels measured in serum and those detected in oral fluid, suggesting that oral fluid analysis may represent an easy, noninvasive means to monitor lithium levels. The aim of this study was to evaluate the analytical performance of rapid assays for lithium measurements in oral fluid.

METHODS

Levels of lithium in oral fluid from psychiatric patients (n = 108 in total) taking lithium medications were quantified using 2 rapid techniques: an automated clinical chemistry analyzer and a novel, commercially available colorimetric lithium assay. These results were compared with those obtained using inductively coupled plasma optical emission spectrometry (ICP-OES).

RESULTS

The mean and median oral fluid lithium levels in this cohort were 1.43-1.61 mM and 1.32-1.52 mM, respectively, depending on the method, with the overall range, across all methods, being 0.213-4.42 mM. Linear regression analysis showed excellent agreement between the oral fluid values measured using ICP-OES and the colorimetric method (r 2 value = 0.926; P < 0.0001; slope = 1.084 ± 0.038). Similarly, excellent agreement was observed between ICP-OES and the automated method (r 2 = 0.872; P < 0.0001; slope = 1.019 ± 0.057).

CONCLUSIONS

These results demonstrate that lithium levels in oral fluid can be rapidly and reliably quantified using colorimetric approaches. These findings may facilitate the development of point-of-care lithium monitoring systems for use in oral fluid.

Comparing measurements of lithium treatment efficacy in people with bipolar disorder: systematic review and meta-analysis

Background

Lithium has long been recognised as an effective treatment for bipolar disorder. Its relative efficacy has been measured with a diverse range of clinical outcomes, resulting in differences in efficacy reporting that have not been systematically reviewed.

Aims

We aimed to identify and compare the various measures of lithium efficacy employed in interventional studies for people with bipolar disorder.

Method

Database (PubMed, Web of Science) and hand searches were performed to identify studies that assessed a clinical response in patients with bipolar disorder who received lithium, up to the end of 2021. We included primary human interventional studies without excluding specific study designs, bipolar disorder subtypes, duration or dosage of lithium treatment. Continuous outcome effects were meta-analysed; binary outcomes were synthesised visually and narratively. The Cochrane risk-of-bias tool was used to assess study-level risk of bias.

Results

Seventy-one studies were included (N = 30 542 ). Approximately two-thirds of participants attained a clinically significant improvement in manic or depressive symptoms, and over 50% achieved remission. About a third required hospital admission (study length 2–12 years) and around 50% needed further treatment to stay well or had recurrence of symptoms; the latter two outcomes tended to be assessed over long-term maintenance periods.

Conclusions

An abundance of measurements have been used to assess lithium's clinical effects, across several study designs. Despite the resultant high heterogeneity, an overall picture of lithium's effects emerges that supports previous literature; between half and two-thirds of patients respond well to lithium across varying outcome measures, baseline mood states, study durations and bipolar disorder subtypes.