[Lithium treatment and potential long-term side effects: a systematic review of the literature]

Endo-Lysosomal and Autophagy Pathway and Ubiquitin-Proteasome System in Mood Disorders: A Review Article

Mood disorders are disabling conditions that cause significant functional impairment. Due to the clinical heterogeneity and complex nature of these disorders, diagnostic and treatment strategies face challenges. The etiology of mood disorders is multifactorial, involving genetic and environmental aspects that are associated with specific biological pathways including inflammation, oxidative stress, and neuroprotection. Alterations in these pathways may reduce the cell's ability to recover from stress conditions occurring during mood episodes. The endo-lysosomal and autophagy pathway (ELAP) and the ubiquitin-proteasome system (UPS) play critical roles in protein homeostasis, impacting neuroplasticity and neurodevelopment. Thus, emerging evidence has suggested a role for these pathways in mental disorders. In the case of neurodegenerative diseases (NDDs), a deeper understanding in the role of ELAP and UPS has been critical to discover new treatment targets. Since it is suggested that NDDs and mood disorders share clinical symptomatology and risk factors, it has been hypothesized that there might be common underlying molecular pathways. Here, we review the importance of the ELAP and UPS for the central nervous system and for mood disorders. Finally, we discuss potential translational strategies for the diagnosis and treatment of major depressive disorder and bipolar disorder associated with these pathways.

A Case of Lithium Encephalopathy with Therapeutic Lithium Levels: The Diagnostic Role of EEG

Introduction. Lithium is considered a first-line therapy for both the acute phase and the maintenance of bipolar disorder. Many studies highlighted its neuroprotective and neuroplastic capacity suggesting a potential usefulness in the treatment of neurodegenerative diseases. Despite the undeniable efficacy, lithium clearly presents several adverse effects including neurotoxicity, also known as lithium encephalopathy, regarding both neurological, psychiatric, and cognitive side effects. In this case, adverse reactions are not always related to its serum levels, possibly appearing within the therapeutic range. Case Presentation. We analyzed the case of a bipolar patient who has been uncontinuosly treated with lithium salts since the onset of the psychopathological picture. Over the years, the average values of lithemia always remained around 0.60-0.70 mEq/L, but in 2019, the patient begun to manifest distal tremors and in the mandibular district accompanied, in the following months, by psychomotor slowdown, generalized tremors, reduced alertness, spatiotemporal disorientation, and aphasia. While alterations referable to neurodegenerative diseases were excluded, EEG maintained rhythm alteration 1 year after the probable intoxication. Discussion. This case confirms the central role of EEG for lithium neurotoxicity, while its dosages are in therapeutic range, being plasma levels are not always indicative of liquoral and neuronal lithium's levels. We highlight the importance of an early diagnosis of lithium encephalopathy proposing EEG as an indispensable tool for assessing lithium neurotoxicity both in acute and chronic intoxication.

The role of CA1 CB1 receptors on lithium-induced spatial memory impairment in rats

Lithium, a glycogen synthase kinase-3β (GSK-3β) inhibitor, prevents cannabinoid withdrawal syndrome, but there is limited data exploring the interaction between lithium and cannabinoid system on memory processes. The present study aimed to test the interaction between dorsal hippocampal (CA1 region) cannabinoid system and lithium on spatial memory in rats. Spatial memory was assessed in Morris Water Maze (MWM) apparatus by a single training session of eight trials. The results showed that pre-training intra-CA1 microinjection of ACPA, the cannabinoid type 1 receptor (CB1r) agonist, at doses of 0.001, 0.01 or 1 µg/rat, or AM251, the cannabinoid type 1 receptor (CB1r) antagonist, at doses of 1, 10 or 100 ng/rat, increased escape latency and traveled distance to the platform, suggesting a spatial learning impairment, whereas intraperitoneal administration of lithium (0.5, 1 or 5 mg/kg) had no effect on spatial learning. Also, rats that received lithium plus a lower dose of ACPA (0.001 µg/rat) or AM251 (1 ng/rat) had successful performance in the MWM. In the probe test, the results showed that pre-training administration of lithium (5 mg/kg) and ACPA (0.01 or 1 µg/rat) but not AM251 (at all doses used) impaired spatial memory retrieval. Also, lower dose of ACPA (0.001 µg/rat) or AM251 (1 ng/rat) potentiated the effect of ineffective doses of lithium (0.5 and 1 mg/kg) on spatial memory retrieval, while restored the effect of effective dose of lithium (5 mg/kg). In conclusion, cannabinoids may have a dual effect on lithium-induced spatial memory impairment in rats.

Effects of maintenance lithium treatment on serum parathyroid hormone and calcium levels: a retrospective longitudinal naturalistic study

OBJECTIVE

The aim of this retrospective longitudinal naturalistic study was to evaluate the effects of maintenance lithium treatment on parathyroid hormone (PTH) and calcium levels.

METHODS

A retrospective longitudinal naturalistic study design was used. Data were collected from the database of a tertiary psychiatric center covering the years 2010-2014. Included were bipolar patients who had never been exposed to lithium and had lithium started, and who had PTH, and total and ionized calcium levels available before and during lithium treatment. Paired t-tests were used to analyze changes in PTH and calcium levels. Linear regressions were performed, with mean lithium level and duration of lithium exposure as independent variables and change in PTH levels as dependent variable.

RESULTS

A total 31 patients were included. The mean duration of lithium treatment was 18.6±11.4 months. PTH levels significantly increased during lithium treatment (+13.55±14.20 pg/mL); the rate of hyperparathyroidism was 12.9%. Neither total nor ionized calcium increased from baseline to follow-up; none of our patients developed hypercalcemia. Linear regressions analyses did not show an effect of duration of lithium exposure or mean lithium level on PTH levels.

CONCLUSION

Lithium-associated stimulation of parathyroid function is more common than assumed to date. Among parameters to be evaluated prior to lithium implementation, calcium and PTH should be added.