Neuroprotection after a first episode of mania: a randomized controlled maintenance trial comparing the effects of lithium and quetiapine on grey and white matter volume

Lithium, the gold standard drug for bipolar disorder: analysis of current clinical studies

Lithium is the gold standard drug in the treatment of bipolar disorder. Despite increasing scientific interest, relatively few patients with bipolar disorder receive lithium therapy. Lithium is the only drug that is effective in the prophylaxis of manic, depressive, and suicidal symptoms. Lithium therapy is also associated with a variety of adverse drug reactions and the need for therapeutic drug monitoring. Numerous studies have focussed on the efficacy and safety of both lithium-monotherapy and lithium-add-on therapy. The aim of this study is to provide a systematic overview of clinical studies on lithium therapy for bipolar disorder from the last 7 years and to present a critical analysis of these studies. The results provide an up-to-date overview of the efficacy, tolerability, and safety of lithium therapy for bipolar disorder and thus improve the pharmacotherapy of bipolar disorder. A total of 59 studies were analysed using various analysis parameters. The studies were also categorised into different subgroups. These are lithium-monotherapy, lithium vs. placebo/drug, and lithium + adjunctive therapy. The majority of the studies (N = 20) had a duration of only 3-8 weeks. Only 13 studies lasted for > 40 weeks. Lithium was superior to aripiprazole, valproic acid, and quetiapine in terms of improving manic symptoms. Lithium therapy resulted in a lower relapse rate compared to valproic acid therapy. Lithium was more neuroprotectively effective than quetiapine. Fourteen of the 22 add-on therapies to lithium showed a predominantly positive effect on the treatment outcome compared to lithium-monotherapy. Only the add-on therapy with sertraline led to a higher rate of study discontinuations than lithium-monotherapy. Lithium is a safe and effective treatment option for children. However, risperidone and quetiapine were superior to lithium in some aspects, which is why these drugs should be considered as an alternative treatment option for children. Collectively, current clinical studies highlight the relevance of lithium in the treatment of bipolar disorder.

New Advances in the Pharmacology and Toxicology of Lithium: A Neurobiologically Oriented Overview

Over the last six decades, lithium has been considered the gold standard treatment for the long-term management of bipolar disorder due to its efficacy in preventing both manic and depressive episodes as well as suicidal behaviors. Nevertheless, despite numerous observed effects on various cellular pathways and biologic systems, the precise mechanism through which lithium stabilizes mood remains elusive. Furthermore, there is recent support for the therapeutic potential of lithium in other brain diseases. This review offers a comprehensive examination of contemporary understanding and predominant theories concerning the diverse mechanisms underlying lithium's effects. These findings are based on investigations utilizing cellular and animal models of neurodegenerative and psychiatric disorders. Recent studies have provided additional support for the significance of glycogen synthase kinase-3 (GSK3) inhibition as a crucial mechanism. Furthermore, research has shed more light on the interconnections between GSK3-mediated neuroprotective, antioxidant, and neuroplasticity processes. Moreover, recent advancements in animal and human models have provided valuable insights into how lithium-induced modifications at the homeostatic synaptic plasticity level may play a pivotal role in its clinical effectiveness. We focused on findings from translational studies suggesting that lithium may interface with microRNA expression. Finally, we are exploring the repurposing potential of lithium beyond bipolar disorder. These recent findings on the therapeutic mechanisms of lithium have provided important clues toward developing predictive models of response to lithium treatment and identifying new biologic targets. SIGNIFICANCE STATEMENT: Lithium is the drug of choice for the treatment of bipolar disorder, but its mechanism of action in stabilizing mood remains elusive. This review presents the latest evidence on lithium's various mechanisms of action. Recent evidence has strengthened glycogen synthase kinase-3 (GSK3) inhibition, changes at the level of homeostatic synaptic plasticity, and regulation of microRNA expression as key mechanisms, providing an intriguing perspective that may help bridge the mechanistic gap between molecular functions and its clinical efficacy as a mood stabilizer.

To what extent does white matter map to cognition in bipolar disorder? A systematic review of the evidence

Cognitive impairment is a prominent feature of bipolar disorder (BD), however the neural substrates underpinning it remain unclear. Several studies have explored white matter as a correlate of cognitive functioning in BD cohorts, but mixed results and varied methodologies from one to another make inferences about this relationship difficult to draw. Here we sought to systematically synthesise the findings of these studies to more clearly explicate the nature and extent of relationships between white matter and cognition in BD and determine best practice methodologies and areas for future research in this area. Using PRISMA guidelines, we identified and systematically reviewed 37 relevant studies, all of which were cross-sectional by design. There was substantial methodological heterogeneity and variability in the clinical presentations of BD cohorts encapsulated within the studies we reviewed, which complicated our synthesis of the findings. Nonetheless, there was some evidence that cognition is related to both white matter macrostructure and microstructure in people with BD. In particular, multiple microstructural studies consistently reported that higher fractional anisotropy, both globally and in the corpus callosum, associated with better complex attention skills and executive functioning. However, several reports did not identify any associations at all, and in general, associations between WM and cognition tended to only be evident in studies utilising larger samples and post-hoc selection of WM regions of interest. Further research with increased statistical power and standardised methods are required moving forward.

Mortality and Lithium-Protective Effects after First-Episode Mania Diagnosis in Bipolar Disorder: A Nationwide Retrospective Cohort Study in Taiwan

INTRODUCTION

This study aimed to estimate all-cause mortality in patients after a first-episode mania (FEM) and examine whether six guideline-recommended medications can reduce mortality.

METHODS

The cohort included population-based FEM samples and matched controls from Taiwan, spanning 2007 to 2018. The primary outcomes assessed were all-cause/suicide-related mortality, while the secondary outcome focused on mortality associated with pharmacological treatments. We compared mortality in post-FEM patients and age-/sex-matched controls without any diagnosed bipolar disorders and patients with and without psychopharmacological treatment using Cox regression analysis, respectively. Statistics were presented with time-to-event adjusted hazard ratios (AHRs) and 95% confidence intervals (CIs).

RESULTS

The study included 54,092 post-FEM patients and 270,460 controls, totaling 2,467,417 person-years of follow-up. Post-FEM patients had higher risks of all-cause mortality (AHR 2.38, 95% CI: 2.31-2.45) and suicide death (10.80, 5.88-19.84) than controls. Lithium (0.62, 0.55-0.70), divalproex (0.89, 0.83-0.95), and aripiprazole (0.81, 0.66-1.00) were associated with reduced all-cause mortality compared to non-users. There were no significant all-cause mortality differences for quetiapine (0.95, 0.89-1.01), risperidone (0.92, 0.82-1.02), and paliperidone (1.24, 0.88-1.76) users. When accounting for drug action onset times in sensitivity analyses, only lithium significantly reduced all-cause mortality (AHR range 0.65-0.72). There were 35 and 16 suicide deaths in post-FEM patients and controls, respectively. No drug had a significant effect on suicide deaths (lithium: 6; divalproex: 7; aripiprazole: 0; quetiapine: 10; risperidone: 4; paliperidone: 1).

CONCLUSION

Post-FEM patients had a higher risk of all-cause/suicide-related mortality, and lithium treatment might reduce all-cause mortality.

Cerebellar morphological differences and associations with extrinsic factors in bipolar disorder type I

BACKGROUND

The neural underpinnings of bipolar disorder (BD) remain poorly understood. The cerebellum is ideally positioned to modulate emotional regulation circuitry yet has been understudied in BD. Literature suggests differences in cerebellar activity and metabolism in BD, however findings on structural differences remain contradictory. Potential reasons include combining BD subtypes, small sample sizes, and potential moderators such as genetics, adverse childhood experiences (ACEs), and pharmacotherapy.

METHODS

We collected 3 T MRI scans from participants with (N = 131) and without (N = 81) BD type I, as well as blood and questionnaires. We assessed differences in cerebellar volumes and explored potentially influential factors.

RESULTS

The cerebellar cortex was smaller bilaterally in participants with BD. Polygenic propensity score did not predict any cerebellar volumes, suggesting that non-genetic factors may have greater influence on the cerebellar volume difference we observed in BD. Proportionate cerebellar white matter volumes appeared larger with more ACEs, but this may result from reduced ICV. Time from onset and symptom burden were not associated with cerebellar volumes. Finally, taking sedatives was associated with larger cerebellar white matter and non-significantly larger cortical volume.

LIMITATIONS

This study was cross-sectional, limiting interpretation of possible mechanisms. Most of our participants were White, which could limit the generalizability. Additionally, we did not account for potential polypharmacy interactions.

CONCLUSIONS

These findings suggest that external factors, such as sedatives and childhood experiences, may influence cerebellum structure in BD and may mask underlying differences. Accounting for such variables may be critical for consistent findings in future studies.

"Addressing the core trait of bipolar disorder": A concept analysis of mood-stabilizing drugs

OBJECTIVE

The term "mood stabilizer" is controversial in the literature and criticized for being imprecise and overly inclusive, having its retirement suggested to avoid misuse. Nevertheless, it continues to be employed as it may still carry important meaning.

METHODS

We employed document analysis for reviewing relevant definitions of mood stabilizer employed in the literature. Then, we clarify the meanings associated with the term by employing evolutionary concept analysis. Based on its results, we present a theoretical model for a mood stabilizer and further match it with evidence gathered from published meta-analyses and other sources for drugs used in the treatment of bipolar disorder.

RESULTS

Concept analysis unearthed four attributes of a mood stabilizer that were nested into the following ascending hierarchy: "not worsening," "acute effects," "prophylactic effects," and "advanced effects." "Prophylactic effects" were often considered the core aspect of a legitimate mood stabilizer.

CONCLUSION

The proposed model uses a hierarchy of attributes that take into account the complexity of the term and help to determine whether a drug is a mood stabilizer. Prophylaxis is pivotal to the concept, whose utility lies in implying a drug able to truly treat bipolar disorder, as opposed to merely targeting symptoms. Consistent use of the term could encourage investigation of drugs that modify long-term outcomes and illness trajectory, instead of simply approaching symptom clusters.

Safety and efficacy of lithium in patients with amyotrophic lateral sclerosis: a systematic review and meta-analysis of randomized controlled trials

OBJECTIVES

This study provides a systematic review and meta-analysis of randomized controlled trials (RCTs) investigating the safety and efficacy of lithium in amyotrophic lateral sclerosis (ALS) patients.

METHODS

PubMed, Web of Science, Cochrane CENTRAL, Scopus, and Your Journals@Ovid were searched up to 9 December 2022. RCTs investigating lithium, either alone or with any supplement, in ALS patients were included. Meta-analysis was performed using RevMan and results are presented in forest plot.

RESULTS

Four RCTs with 469 patients met the inclusion criteria and were included in our study. Lithium doses varied among the included studies and one study used a combined therapy of lithium with valproate. Meta-analysis showed no difference between lithium and placebo regarding severe adverse events (odds ratio = 1.13, 95% confidence interval: 0.73 to 1.75, P = 0.58). No significant differences were observed with regard to survival rate between the two groups (hazard ratio = 0.95, 95% confidence interval: 0.65 to 1.37, P = 0.77). There were also no significant differences between the two groups with regard to average changes of revised amyotrophic lateral sclerosis functional rating scale (P = 0.35) and forced vital capacity percentage predicted (P = 0.73). Subgroup analysis showed no significant differences regarding all investigated outcomes either for lithium alone or lithium with valproate.

CONCLUSION

Current evidence suggests a safety profile with no benefit of lithium for ALS. However, given the limited number of RCTs and the safety findings, we recommend further well-designed RCTs to investigate lithium and valproate in ALS patients.

Mania-related effects on structural brain changes in bipolar disorder - a narrative review of the evidence

Cross-sectional neuroimaging studies show that bipolar disorder is associated with structural brain abnormalities, predominantly observed in prefrontal and temporal cortex, cingulate gyrus, and subcortical regions. However, longitudinal studies are needed to elucidate whether these abnormalities presage disease onset or are consequences of disease processes, and to identify potential contributing factors. Here, we narratively review and summarize longitudinal structural magnetic resonance imaging studies that relate imaging outcomes to manic episodes. First, we conclude that longitudinal brain imaging studies suggest an association of bipolar disorder with aberrant brain changes, including both deviant decreases and increases in morphometric measures. Second, we conclude that manic episodes have been related to accelerated cortical volume and thickness decreases, with the most consistent findings occurring in prefrontal brain areas. Importantly, evidence also suggests that in contrast to healthy controls, who in general show age-related cortical decline, brain metrics remain stable or increase during euthymic periods in bipolar disorder patients, potentially reflecting structural recovering mechanisms. The findings stress the importance of preventing manic episodes. We further propose a model of prefrontal cortical trajectories in relation to the occurrence of manic episodes. Finally, we discuss potential mechanisms at play, remaining limitations, and future directions.

Brain morphometric features predict medication response in youth with bipolar disorder: a prospective randomized clinical trial

BACKGROUND

Identification of treatment-specific predictors of drug therapies for bipolar disorder (BD) is important because only about half of individuals respond to any specific medication. However, medication response in pediatric BD is variable and not well predicted by clinical characteristics.

METHODS

A total of 121 youth with early course BD (acute manic/mixed episode) were prospectively recruited and randomized to 6 weeks of double-blind treatment with quetiapine (n = 71) or lithium (n = 50). Participants completed structural magnetic resonance imaging (MRI) at baseline before treatment and 1 week after treatment initiation, and brain morphometric features were extracted for each individual based on MRI scans. Positive antimanic treatment response at week 6 was defined as an over 50% reduction of Young Mania Rating Scale scores from baseline. Two-stage deep learning prediction model was established to distinguish responders and non-responders based on different feature sets.

RESULTS

Pre-treatment morphometry and morphometric changes occurring during the first week can both independently predict treatment outcome of quetiapine and lithium with balanced accuracy over 75% (all p < 0.05). Combining brain morphometry at baseline and week 1 allows prediction with the highest balanced accuracy (quetiapine: 83.2% and lithium: 83.5%). Predictions in the quetiapine and lithium group were found to be driven by different morphometric patterns.

CONCLUSIONS

These findings demonstrate that pre-treatment morphometric measures and acute brain morphometric changes can serve as medication response predictors in pediatric BD. Brain morphometric features may provide promising biomarkers for developing biologically-informed treatment outcome prediction and patient stratification tools for BD treatment development.

Choroidal Structural Alterations and Choroidal Vascularity Index in Bipolar Disorder Patients

PURPOSE

The aim of this study was to compare bipolar disorder (BD) patients with age- and sex-matched healthy individuals in order to assess the choroidal structural alterations, retinal nerve fiber layer (RNFL) thickness, and retinal changes in BD patients using encanhed depth imaging optic coherence tomography (EDI-OCT).

METHOD

For this research, 39 eyes of BD patients and 36 eyes of age-matched healthy volunteers were used. Five locations were used to assess the choroidal thickness (CT): subfoveal, 500 µm nasal and 1500 µm nasal to the fovea, 500 µm temporal and 1500 µm temporal to the fovea. Image-J was used to determine the total choroidal area (TCA), luminal area (LA), and choroidal vascularity index (CVI). The Spectralis-OCT device was used to evaluate the central macular thickness (CMT), retinal nerve fiber layer (RNFL), and ganglion cell layer (GCL). The data were statistically compared.

RESULTS

BD patients had significantly decreased subfoveal, nasal, and temporal CTs than controls (for all three, p = 0.0001). The results of CMT and GCL were found to be thinner than controls. (for all p=0.0001) In comparison to the controls, the mean TCA and LA were decreased in the BD group. (p=0.0001, p=0.0001  respectively,).  Between the RNFL and CVI values in the BD and control groups, there was no statistically significant difference (p>0.05).

CONCLUSION

The results of this investigation showed that the retina and choroid of patients with BD had considerable anatomical changes.

Increased cortical surface area but not altered cortical thickness or gyrification in bipolar disorder following stabilisation from a first episode of mania

BACKGROUND

Despite reports of altered brain morphology in established bipolar disorder (BD), there is limited understanding of when these morphological abnormalities emerge. Assessment of patients during the early course of illness can help to address this gap, but few studies have examined surface-based brain morphology in patients at this illness stage.

METHODS

We completed a secondary analysis of baseline data from a randomised control trial of BD individuals stabilised after their first episode of mania (FEM). The magnetic resonance imaging scans of n = 35 FEM patients and n = 29 age-matched healthy controls were analysed. Group differences in cortical thickness, surface area and gyrification were assessed at each vertex of the cortical surface using general linear models. Significant results were identified at p < 0.05 using cluster-wise correction.

RESULTS

The FEM group did not differ from healthy controls with regards to cortical thickness or gyrification. However, there were two clusters of increased surface area in the left hemisphere of FEM patients, with peak coordinates falling within the lateral occipital cortex and pars triangularis.

CONCLUSIONS

Cortical thickness and gyrification appear to be intact in the aftermath of a first manic episode, whilst cortical surface area in the inferior/middle prefrontal and occipitoparietal cortex is increased compared to age-matched controls. It is possible that increased surface area in the FEM group is the outcome of abnormalities in a premorbidly occurring process. In contrast, the findings raise the hypothesis that cortical thickness reductions seen in past studies of individuals with more established BD may be more attributable to post-onset factors.

Brain-gut microbiota multimodal predictive model in patients with bipolar depression

BACKGROUND

The "microbiota-gut-brain axis" which bridges the brain and gut microbiota is involved in the pathological mechanisms of bipolar disorder (BD), but rare is known about the exact association patterns and the potential for clinical diagnosis and treatment outcome prediction.

METHODS

At baseline, fecal samples and resting-state MRI data were collected from 103 BD depression patients and 39 healthy controls (HCs) for metagenomic sequencing and network-based functional connectivity (FC), grey matter volume (GMV) analyses. All patients then received 4-weeks quetiapine treatment and were further classified as responders and non-responders. Based on pre-treatment datasets, the correlation networks were established between gut microbiota and neuroimaging measures and the multimodal kernal combination support vector machine (SVM) classifiers were constructed to distinguish BD patients from HCs, and quetiapine responders from non-responders.

RESULTS

The multi-modal pre-treatment characteristics of quetiapine responders, were closer to the HCs compared to non-responders. And the correlation network analyses found the substantial correlations existed in HC between the Anaerotruncus_ unclassified，Porphyromonas_asaccharolytica，Actinomyces_graevenitzii et al. and the functional connectomes involved default mode network (DMN),somatomotor (SM), visual, limbic and basal ganglia networks were disrupted in BD. Moreover, in terms of the multimodal classifier, it reached optimized area under curve (AUC-ROC) at 0.9517 when classified BD from HC, and also acquired 0.8292 discriminating quetiapine responders from non-responders, which consistently better than even using the best unique modality.

LIMITATIONS

Lack post-treatment and external validation datasets; size of HCs is modest.

CONCLUSIONS

Multi-modalities of combining pre-treatment gut microbiota with neuroimaging endophenotypes might be a superior approach for accurate diagnosis and quetiapine efficacy prediction in BD.

Lithium increases cortical and subcortical volumes in subjects with bipolar disorder

Bipolar disorder (BD) is a highly variable and burdensome disease for patients and caregivers. A BD diagnosis almost triples the likelihood of developing dementia as the disease progresses. Neurocognitive reserve appears to be one of the most important influences on lifelong functional outcomes and quality of life in BD. Though several prior studies have assessed the effects of lithium on regional gray and white matter volumes in this population, representative cohorts are typically middle-aged, have a more severe pathology, and are not as commonly assessed in the depressive phase (which represents the majority of most patients' lifespans outside of remission). Here we have shown that positive adaptations with lithium can be observed throughout the brain after only six weeks of monotherapy at low-therapeutic serum levels. Importantly, these results remove some confounders seen in prior studies (patients were treatment free at time of enrollment and mostly treatment naïve). This cohort also includes underrepresented demographics in the literature (young adult patients, mostly bipolar II, and exclusively in the depressed phase). These findings bolster the extensive body of evidence in support of long-term lithium therapy in BD, furthering the possibility of its expanded use to wider demographics.

Evaluation of progressive retinal degeneration in Bipolar disorder patients over a period of 5 years

PURPOSE

To quantify visual and retinal changes in patients with bipolar disorder (BD) over 5 years, compared with controls.

METHODS

Thirty-eight patients with BD and 122 healthy subjects underwent visual acuity (VA) evaluation, contrast sensitivity vision testing (CSV) with the Pelli Robson and CSV 1000E tests, and retinal thicknesses measurement (ganglion cell layer - GCL- and retinal nerve fiber layer -RNFL-) using Spectralis Optical Coherence Tomography (OCT). All subjects were re-evaluated after 5 years. The relationship between progressive structural changes and disease duration was analysed.

RESULTS

Visual function parameters in BD patients remained unchanged during the follow up period. A progressive decrease affecting macular and peripapillary RNFL thickness (p < 0.050) was observed in patients. Progressive changes in BD were more pronounced when compared with healthy controls (p < 0.050). A significant correlation between GCL thickness changes and disease duration was found (GCL outer temporal, r=-0.680, p = 0.016; GCL central, r=-0.540, p = 0.038).

CONCLUSIONS

Progressive axonal loss was detected in BD patients. Visual function parameters were not affected after the 5-year follow up. Despite observed changes in the neuroretina of patients with BD, axonal degeneration in these patients seemed to be mild and might be slowed down by other factors such as BD treatments.

Neural network of bipolar disorder: Toward integration of neuroimaging and neurocircuit-based treatment strategies

Bipolar disorder (BD) is a complex psychiatric disorder characterized by dysfunctions in three domains including emotional processing, cognitive processing, and psychomotor dimensions. However, the neural underpinnings underlying these clinical profiles are not well understood. Based on the reported data, we hypothesized that (i) the core neuropathology in BD is damage in fronto-limbic network, which is associated with emotional dysfunction; (ii) changes in intrinsic brain network, such as sensorimotor network, salience network, default-mode network, central executive network are associated with impaired cognition function; and (iii) beyond the dopaminergic-driven basal ganglia-thalamo-cortical motor circuit modulated by other neurotransmitter systems, such as serotonin (subcortical-cortical modulation), the sensorimotor network and related motor function modulated by other non-motor networks such as the default-mode network are involved in psychomotor function. In this review, we propose a neurocircuit-based clinical characteristics and taxonomy to guide the treatment of BD. We draw on findings from neuropsychological and neuroimaging studies in BD and link variations in these clinical profiles to underlying neurocircuit dysfunctions. We consider pharmacological, psychotherapy, and neuromodulatory treatments that could target those specific neurocircuit dysfunctions in BD. Finally, it is suggested that the methods of testing the neurocircuit-based taxonomy and important limitations to this approach should be considered in future.

Therapeutic Interventions to Mitigate Mitochondrial Dysfunction and Oxidative Stress–Induced Damage in Patients with Bipolar Disorder

Bipolar disorder (BD) is characterized by mood changes, including recurrent manic, hypomanic, and depressive episodes, which may involve mixed symptoms. Despite the progress in neurobiological research, the pathophysiology of BD has not been extensively described to date. Progress in the understanding of the neurobiology driving BD could help facilitate the discovery of therapeutic targets and biomarkers for its early detection. Oxidative stress (OS), which damages biomolecules and causes mitochondrial and dopamine system dysfunctions, is a persistent finding in patients with BD. Inflammation and immune dysfunction might also play a role in BD pathophysiology. Specific nutrient supplements (nutraceuticals) may target neurobiological pathways suggested to be perturbed in BD, such as inflammation, mitochondrial dysfunction, and OS. Consequently, nutraceuticals may be used in the adjunctive treatment of BD. This paper summarizes the possible roles of OS, mitochondrial dysfunction, and immune system dysregulation in the onset of BD. It then discusses OS-mitigating strategies that may serve as therapeutic interventions for BD. It also analyzes the relationship between diet and BD as well as the use of nutritional interventions in the treatment of BD. In addition, it addresses the use of lithium therapy; novel antipsychotic agents, including clozapine, olanzapine, risperidone, cariprazine, and quetiapine; and anti-inflammatory agents to treat BD. Furthermore, it reviews the efficacy of the most used therapies for BD, such as cognitive–behavioral therapy, bright light therapy, imagery-focused cognitive therapy, and electroconvulsive therapy. A better understanding of the roles of OS, mitochondrial dysfunction, and inflammation in the pathogenesis of bipolar disorder, along with a stronger elucidation of the therapeutic functions of antioxidants, antipsychotics, anti-inflammatory agents, lithium therapy, and light therapies, may lead to improved strategies for the treatment and prevention of bipolar disorder.

Lithium: Current Clinical Guidelines for Nurse Practitioners

Bipolar disorder is a serious neuroprogressive disorder associated with structural and functional brain changes, multiple comorbidities, and heightened risk for suicide. Lithium has been a first-line treatment for bipolar disorder for more than 50 years and recent research suggests that early identification and treatment of bipolar disorder with lithium can alter the progression of the illness. The purpose of the current article is to review evidence for lithium's neurotrophic and neuroprotective actions and clinical guidelines for safe and effective use. [Journal of Psychosocial Nursing and Mental Health Services, 60(1), 6-9.].

Effects of lithium use on the white matter of patients with bipolar disorder - a systematic review

BACKGROUND

Several studies revealed changes in the microstructure of white matter in bipolar disorder patients. Lithium has been reported as having neuroprotective effects. However, its effect on the white matter remains unclear. This systematic review aims to identify the existing clinical evidence of lithium's effect on the white matter from bipolar disorder patients.

METHODS

PRISMA guidelines were followed for a systematic literature review to assess the effect of lithium on the white matter of patients with bipolar disorder. From a total of 204 studies screened, 16 were included in the final systematic review. The quality assessment of the included records was assessed by the Newcastle-Ottawa scale.

RESULTS

Most studies included (13 out of 16) evaluated diffusion tensor imaging measures to assess white matter integrity. Of these, eleven reported a positive effect of lithium on the integrity of white matter of bipolar disorder patients. Two reported no effect. Two studies evaluated white matter volume. The first reported that lithium attenuates the reduction of white matter volume over time, and the second reported significantly smaller white matter volume in non-lithium-using patients. The last evaluated ventricular brain ratio and reported that patients treated with lithium did not have a significantly greater ventricular size than their normal control counterparts.

CONCLUSIONS

Lithium appears to positively influence the evolution of the white matter abnormalities described in bipolar disorder patients. Should this information be confirmed in future research, and given its important mood stabilizer effect, it could further reinforce the use of lithium in the treatment of bipolar disorder.

Duration of untreated illness and bipolar disorder: time for a new definition? Results from a cross-sectional study

BACKGROUND

We primarily aimed to explore the associations between duration of untreated illness (DUI), treatment response, and functioning in a cohort of patients with bipolar disorder (BD).

METHODS

261 participants with BD were recruited. DUI was defined as months from the first affective episode to the start of a mood-stabilizer. The functioning assessment short test (FAST) scores and treatment response scores for lithium, valproate, or lamotrigine according to the Alda Scale Total Score (TS) were compared between patients with short (<24 months) or long DUI. Differences in FAST scores among good (GR; TS≥7), poor (PR; TS=2-6), or non-responders (NR; TS<2) to each mood-stabilizer were analyzed. Linear regression was computed using the FAST global score as the dependent variable.

RESULTS

DUI and FAST scores showed no statistically significant correlation. Patients with a longer DUI showed poorer response to lithium (Z=-3.196; p<0.001), but not to valproate or lamotrigine. Response to lithium (β=-1.814; p<0.001), number of hospitalizations (β=0.237; p<0.001), and illness duration (β=0.160; p=0.028) were associated with FAST total scores. GR to lithium was associated with better global functioning compared to PR or NR [H=27.631; p<0.001].

LIMITATIONS

The retrospective design could expose our data to a recall bias. Also, only few patients were on valproate or lamotrigine treatment.

CONCLUSIONS

Poor functioning in BD could be the result of multiple affective relapses, rather than a direct effect of DUI. A timely diagnosis with subsequent effective prophylactic treatment, such as lithium, may prevent poor functional outcomes in real-world patients with BD.

A Systematic Review of Cognition-Brain Morphology Relationships on the Schizophrenia-Bipolar Disorder Spectrum

The nature of the relationship between cognition and brain morphology in schizophrenia-spectrum disorders (SSD) and bipolar disorder (BD) is uncertain. This review aimed to address this, by providing a comprehensive systematic investigation of links between several cognitive domains and brain volume, cortical thickness, and cortical surface area in SSD and BD patients across early and established illness stages. An initial search of PubMed and Scopus databases resulted in 1486 articles, of which 124 met inclusion criteria and were reviewed in detail. The majority of studies focused on SSD, while those of BD were scarce. Replicated evidence for specific regions associated with indices of cognition was minimal, however for several cognitive domains, the frontal and temporal regions were broadly implicated across both recent-onset and established SSD, and to a lesser extent BD. Collectively, the findings of this review emphasize the significance of both frontal and temporal regions for some domains of cognition in SSD, while highlighting the need for future BD-related studies on this topic.

Automatic Diagnosis of Bipolar Disorder Using Optical Coherence Tomography Data and Artificial Intelligence

Background: The aim of this study is to explore an objective approach that aids the diagnosis of bipolar disorder (BD), based on optical coherence tomography (OCT) data which are analyzed using artificial intelligence. Methods: Structural analyses of nine layers of the retina were analyzed in 17 type I BD patients and 42 controls, according to the areas defined by the Early Treatment Diabetic Retinopathy Study (ETDRS) chart. The most discriminating variables made up the feature vector of several automatic classifiers: Gaussian Naive Bayes, K-nearest neighbors and support vector machines. Results: BD patients presented retinal thinning affecting most layers, compared to controls. The retinal thickness of the parafoveolar area showed a high capacity to discriminate BD subjects from healthy individuals, specifically for the ganglion cell (area under the curve (AUC) = 0.82) and internal plexiform (AUC = 0.83) layers. The best classifier showed an accuracy of 0.95 for classifying BD versus controls, using as variables of the feature vector the IPL (inner nasal region) and the INL (outer nasal and inner inferior regions) thickness. Conclusions: Our patients with BD present structural alterations in the retina, and artificial intelligence seem to be a useful tool in BD diagnosis, but larger studies are needed to confirm our findings.

Longitudinal grey matter changes following first episode mania in bipolar I disorder: A systematic review

BACKGROUND

While widespread grey matter (GM) changes are seen in bipolar I disorder (BD-I), it is unclear how early in the illness such changes emerge. To date there has been little synthesis of findings regarding longitudinal grey matter changes early in the course of BD-I. We conducted a systematic review to examine the evolution of GM changes in BD-I patients following the first episode of mania (FEM).

METHODS

Following PRISMA guidelines, we conducted a systematic review of studies examining longitudinal changes in GM volume (GMV), cortical thickness and/or surface area in BD-I patients following FEM. We qualitatively synthesized results regarding longitudinal GM changes in BD-I patients.

RESULTS

Fifteen studies met inclusion criteria, all examining GMV changes. Longitudinal ACC volume decrease following FEM was the most replicated finding, but was only reported in 4 out of 7 studies that examined this region as part of a whole brain/region of interest analysis, with 2 of these positive studies using an overlapping patient sample. The impact of episode recurrence, medications, and other clinical factors was inconsistently examined.

LIMITATIONS

The literature regarding GM changes early in BD-I is highly inconsistent, likely due to heterogeneity in participant characteristics, imaging methodology/analysis and duration of follow up.

CONCLUSIONS

Though there was some suggestion that structural ACC changes may represent a marker for neuroprogression following FEM, results were too inconsistent to draw any conclusions. Larger longitudinal studies examining cortical thickness/surface area, and the influence of relevant clinical factors, are needed to better understand neuroprogression in early BD-I.

Illness stage and predominant polarity in bipolar disorder: Correlation with burden of illness and moderation of treatment outcome

Bipolar disorder often follows a set progression best described in stages where advanced stages are associated with poorer outcomes. Bipolar disorder is also often characterized by a predominance of episode polarity, where some individuals experience more depressive episodes (termed predominant depressive polarity) while others experience more hypo/manic episodes (termed predominant hypo/manic polarity). We examined the associations between staging and predominant polarity with measures of illness burden and treatment outcome utilizing data from a six-month comparative effectiveness trial of lithium and quetiapine in bipolar disorder (Bipolar CHOICE). We used number of self-reported lifetime mood (depressive and hypo/manic) episodes as a proxy for staging and ratio of depressive to manic episodes to define predominant polarity. Polarity and staging were correlated with several measures of burden of illness. Childhood abuse was correlated with more lifetime mood episodes, while more depressive episodes and depressive polarity were correlated with more anxiety disorder comorbidity. Depressive polarity was also correlated with more past trials of psychotropics, particularly antidepressants. However, neither staging nor predominant polarity moderated the randomized treatment effect of lithium vs. quetiapine. Number of depressive episodes in the past year was identified as a potential predictor of overall worse treatment outcome, regardless of medication condition. In conclusion, though staging and predominant episode polarity correlated with several measures of illness burden, they were not associated with differential treatment outcomes. This could be because many of our patients presented for treatment at advanced stages of illness and further highlights the need for early intervention in bipolar disorder.

Changes in the brain structural connectome after a prospective randomized clinical trial of lithium and quetiapine treatment in youth with bipolar disorder

The goals of the current study were to determine whether topological organization of brain structural networks is altered in youth with bipolar disorder, whether such alterations predict treatment outcomes, and whether they are normalized by treatment. Youth with bipolar disorder were randomized to double-blind treatment with quetiapine or lithium and assessed weekly. High-resolution MRI images were collected from children and adolescents with bipolar disorder who were experiencing a mixed or manic episode (n = 100) and healthy youth (n = 63). Brain networks were constructed based on the similarity of morphological features across regions and analyzed using graph theory approaches. We tested for pretreatment anatomical differences between bipolar and healthy youth and for changes in neuroanatomic network metrics following treatment in the youth with bipolar disorder. Youth with bipolar disorder showed significantly increased clustering coefficient (Cp) (p = 0.009) and characteristic path length (Lp) (p = 0.04) at baseline, and altered nodal centralities in insula, inferior frontal gyrus, and supplementary motor area. Cp, Lp, and nodal centrality of the insula exhibited normalization in patients following treatment. Changes in these neuroanatomic parameters were correlated with improvement in manic symptoms but did not differ between the two drug therapies. Baseline structural network matrices significantly differentiated medication responders and non-responders with 80% accuracy. These findings demonstrate that both global and nodal structural network features are altered in early course bipolar disorder, and that pretreatment alterations in neuroanatomic features predicted treatment outcome and were reduced by treatment. Similar connectome normalization with lithium and quetiapine suggests that the connectome changes are a downstream effect of both therapies that is related to their clinical efficacy.

Advances in the psychopharmacotherapy of bipolar disorder type I

INTRODUCTION

Research into the pharmacologic management of bipolar type I illness continues to progress.

AREAS COVERED

Randomized clinical trials performed with type I bipolar disorder in the years 2015 to August 2020 are reviewed. There are new indications for the use of cariprazine, for bipolar mania and depression, and a long-acting injectable formulation of aripiprazole has also been approved for relapse prevention in bipolar illness. Most of the randomized clinical trials are effectiveness studies.

EXPERT OPINION

Over the 20 years from 1997 through 2016, the use of lithium and other mood stabilizers has declined by 50%, while the use of both second-generation antipsychotics (SGAs) and antidepressants has increased considerably. Over the same time period (1990-2017), disability-adjusted life years (DALYs) increased by 54.4%, from 6.02 million in 1990 to 9.29 million in 2017 which is greater than the 47.74% increase in incidence of the disease, suggesting that the changes in prescribing patterns have not been helpful for our patients. Furthermore, recent effectiveness studies continue to confirm the superiority of lithium and other mood stabilizers in the management of bipolar illness for both psychiatric and medical outcomes, reaffirming their role as foundational treatments in the management of type I bipolar disorder. Clinicians need to reassess their prescribing habits.

Overview of lithium's use: a nationwide survey

BACKGROUND

Lithium is considered the gold standard treatment for bipolar disorder (BD). Current clinical guidelines and scientific evidence support its use as a first-line treatment in BD. However, over the last two decades, there has been a downward tendency in lithium's use in several developed countries. Based on a nationwide survey, this study's objective is to analyze in a large sample of psychiatrists relevant issues of the use of lithium salts in BD.

METHODS

Data were collected through an anonymous survey sent by email among 500 psychiatrists who belong to a National Society of Psychiatry (Spanish Society of Biological Psychiatry). The survey is a self-administered questionnaire consisting of 21 items on the most key aspects of lithium's use (indication, dosage, monitoring, and information for patients).

RESULTS

212 psychiatrists completed the survey. 70% of psychiatrists prescribe lithium to more than 50% of patients diagnosed with BD. Adverse effects are the main reason not to use lithium salts. Over 75% of the participants consider lithium salts the treatment of choice for the maintenance phase of BD, both in women and men. Most of the participants (> 50%) start lithium after the first affective episode, use conservative plasma concentrations (0.6-0.8 mmol/L), and generally prescribe it twice a day. 57% of psychiatrists who treat patients under 18 do not use lithium in this population. About 70% of the survey respondents use official protocols to inform and monitor patients on lithium treatment.

CONCLUSIONS

From the results of the present study, it can be concluded that the use of lithium in Spain is in line with the recommendations of the main international clinical guidelines and current scientific literature. The first reason not to prescribe lithium in our country is the perception of its adverse effects and not the aspects related to its practical use or its effectiveness. Considering that BD is a chronic disease with a typical onset in adolescence, the low rate of prescription of lithium salts in patients under 18 must be thoroughly studied.

Clinical and neurostructural characteristics among youth with familial and non-familial bipolar disorder: Family history and youth bipolar disorder

BACKGROUND

Bipolar disorder (BD) is highly heritable and often severe, particularly when illness onset occurs early in life. There is limited knowledge regarding the clinical and neurostructural correlates of family history of BD among youth with BD.

METHODS

Clinical characteristics were evaluated in 197 youth with BD, ages 13-20 years, including 87 with familial BD and 110 with non-familial BD. Structural neuroimaging was examined in a subsample of familial BD (n=39), non-familial BD (n=42), and healthy control (HC, n=58) youth. Region of interest (ROI) analyses of anterior cingulate cortex (ACC), inferior frontal gyrus (IFG), and amygdala were complemented by whole-brain vertex-wise analyses.

RESULTS

Youth with familial BD had more family history of other psychiatric disorders, less severe worst manic episode, and less treatment with lithium, selective serotonin reuptake inhibitor (SSRI) antidepressants, and any lifetime psychiatric medications. None of these findings survived after correction for multiple comparisons. There were no significant between-group differences in ROI analyses. In whole-brain analyses, significant differences in cortical thickness were as follows: familial and non-familial BD < HC in left precentral gyrus and right inferior parietal lobe; familial BD < HC in left superior frontal gyrus; non-familial BD < HC in right precentral gyrus.

LIMITATIONS

Relatives did not complete full diagnostic interviews.

CONCLUSIONS

There were relatively few differences in clinical and neurostructural correlates related to family history of BD in youth with BD. Current findings suggest that family history of BD is not a strong contributor to the clinical or neuroimaging phenotypes in youth with BD.

Brain morphology does not clearly map to cognition in individuals on the bipolar-schizophrenia-spectrum: a cross-diagnostic study of cognitive subgroups

BACKGROUND

Characterisation of brain morphological features common to cognitively similar individuals with bipolar disorder (BD) and schizophrenia spectrum disorders (SSD) may be key to understanding their shared neurobiological deficits. In the current study we examined whether three previously characterised cross-diagnostic cognitive subgroups differed among themselves and in comparison to healthy controls across measures of brain morphology.

METHOD

T1-weighted structural magnetic resonance imaging scans were obtained for 143 individuals; 65 healthy controls and 78 patients (SSD, n = 40; BD I, n = 38) classified into three cross-diagnostic cognitive subgroups: Globally Impaired (n = 24), Selectively Impaired (n = 32), and Superior/Near-Normal (n = 22). Cognitive subgroups were compared to each other and healthy controls on three separate analyses investigating (1) global, (2) regional, and (3) vertex-wise comparisons of brain volume, thickness, and surface area.

RESULTS

No significant subgroup differences were evident in global measures of brain morphology. In region of interest analyses, the Selectively Impaired subgroup had greater right accumbens volume than those Superior/Near-Normal subgroup and healthy controls, and the Superior/Near-Normal subgroup had reduced volume of the left entorhinal region compared to all other groups. In vertex-wise comparisons, the Globally Impaired subgroup had greater right precentral volume than the Selectively Impaired subgroup, and thicker cortex in the postcentral region relative to the Superior/Near-Normal subgroup.

LIMITATIONS

Exploration of medication effects was limited in our data.

CONCLUSIONS

Although some differences were evident in this sample, generally cross-diagnostic cognitive subgroups of individuals with SSD and BD did not appear to be clearly distinguished by patterns in brain morphology.

Preservation of Gray Matter Volume in Early Stage of Bipolar Disorder: A Case for Early Intervention: Préservation du volume de matière grise au stade précoce du trouble bipolaire: un cas pour intervention précoce

OBJECTIVE

It has been proposed that different stages of the bipolar disorder might have distinct neurobiological changes. However, the evidence for this has not been consistent, as the studies in early stages of the illness are limited by small sample sizes. The purpose of this study was to investigate the gray matter volume changes in bipolar patients who recently recovered from their first episode of mania (FEM).

METHODS

Using a whole-brain voxel-based analysis, we compared the regional gray matter volumes of 61 bipolar patients who have recovered from their FEM in the past 3 months with 43 age- and gender-matched healthy participants. We also performed a series of subgroup analyses to determine the effects of hospitalization during the FEM, history of depressive episodes, and exposure to lithium.

RESULTS

No statistically significant difference was found between gray matter volumes of FEM patients and healthy participants, even at a more liberal threshold (P < 0.001, uncorrected for multiple comparisons). Voxel-based subgroup analyses did not reveal significant gray matter differences except for a trend toward decreased gray matter volume in left lateral occipital cortex (P < 0.001, uncorrected) in patients with a previous history of depression.

CONCLUSION

This study represents the largest structural neuroimaging investigation of FEM published to date. Early stage of bipolar disorder was not found to be associated with significant gray matter volume changes. Our findings suggest that there might be a window of opportunity for early intervention strategies to prevent or delay neuroprogression in bipolar disorder.

Ganglion Cell and Retinal Nerve Fiver Layers Correlated with Time Disease of Bipolar Disorder Using 64 Cell Grid OCT Tool

MATERIALS AND METHODS

Twenty-five eyes of 25 patients with bipolar disorder and 74 eyes of 74 healthy controls underwent retinal measurements of retinal nerve fiber layer (RNFL) and ganglion cell layer (GCL) thickness. Measurements were obtained using the Spectralis-OCT device with the new Posterior Pole protocol which assesses the macular area by analyzing retinal thickness in a grid of 64 (8*8) cells.

RESULTS

Significant differences (p < 0.05) in RNFL and GCL thickness were found between BD patients and healthy controls, in parafoveal and perifoveal cells respectively. Significant inverse correlations were found between RNFL and GCL thinning at their thickest location and the duration of bipolar disorder. Several predictive variables were observed with a binary logistic regression for the presence/absence of BD: cell 1.3 RNFL (p = 0.028) and GCL in cells 7.8 (p = 0.012), 2.7 (p = 0.043) and 1.3 (p = 0.047).

CONCLUSION

Posterior Pole OCT protocol is a useful tool to assess changes in the inner retinal layers in bipolar disorder. These observed changes, especially those affecting the GCL, may be associated with disease evolution and may be predictive of the presence of the disease. OCT data could potentially be a useful tool for clinicians to diagnose and monitor BD patients.

VISUAL FUNCTION AND RETINAL CHANGES IN PATIENTS WITH BIPOLAR DISORDER

PURPOSE

To evaluate visual and retinal changes in patients with bipolar disorder. To analyze the correlation between structural changes and visual function parameters.

METHODS

Thirty patients with bipolar disorder and 80 healthy controls underwent visual function evaluation with Early Treatment Diabetic Retinopathy Study charts at 100%, 2.50%, and 1.25% contrast, Pelli-Robson chart, and color vision Farnsworth and Lanthony tests. Analysis of the different retinal layers was performed using Spectralis optical coherence tomography with automated segmentation software. Correlation analysis between structural and functional parameters was conducted.

RESULTS

Patients with bipolar disorder presented worse color vision compared with controls (Lanthony's index, P = 0.002). Full macular thickness, the retinal nerve fiber layer (RNFL), ganglion cell layer, and inner plexiform layer were reduced in patients compared with healthy individuals (P < 0.005). The inner nuclear layer was significantly thickened in patients (P < 0.005). Peripapillary RNFL thickness was reduced in all temporal sectors (P < 0.005). Significant correlations were found between visual acuity and the RNFL thickness, the Pelli-Robson score and the inner plexiform layer, and between the Lanthony's color index and the ganglion cell layer thickness.

CONCLUSION

Patients with bipolar disorder present quantifiable thinning of the macular RNFL, ganglion cell layer, and inner plexiform layer, as well as in the peripapillary RNFL thickness, and increasing thinning in the inner nuclear layer.

Lithium - past, present, future

OBJECTIVES

A narrative review of past, present, and future of lithium use in psychiatry.

METHODS

The most important references on the topic were reviewed with special emphasis on the author's works.

RESULTS

The history of medical and psychiatric use of lithium dates back to more than one and a half-century ago. However, modern psychiatric history began with the publication of John Cade, in 1949, showing a therapeutic effect of lithium in mania. Currently, lithium is a drug of choice as a mood-stabilizer for the maintenance treatment of the bipolar disorder. The second most important use of lithium is probably augmentation of antidepressants in treatment-resistant depression. In addition to its mood-stabilizing properties, lithium exerts anti-suicidal, immunomodulatory, and neuroprotective action. The drug may protect against dementia and some promising effects of lithium in neurodegenerative disorders have been observed.

CONCLUSION

Given the clinical and biological properties of lithium, this drug is presently greatly underutilized in mood disorders. Therefore, the efforts should be undertaken for challenging a skepticism about the use of lithium and optimizing its long-term administration. In such a way, more patients with mood disorders can become the beneficiaries of lithium's therapeutic action. KEY POINTS Lithium is a drug of choice as a mood-stabiliser for the maintenance treatment of bipolar disorder. Augmentation of antidepressants by lithium is one of the best strategies in treatment-resistant depression. Lithium exerts anti-suicidal, immunomodulatory, and neuroprotective action and may protect against dementia. Despite the evidence for the efficacy and added favourable properties, lithium is greatly underutilised in mood disorders. Challenging a scepticism about the use of lithium and optimising its long-term administration can make more patients with mood disorders the beneficiaries of lithium's therapeutic action.

In vivo hippocampal subfield volumes in bipolar disorder—A mega‐analysis from The Enhancing Neuro Imaging Genetics through Meta‐Analysis Bipolar Disorder Working Group

The hippocampus consists of anatomically and functionally distinct subfields that may be differentially involved in the pathophysiology of bipolar disorder (BD). Here we, the Enhancing NeuroImaging Genetics through Meta‐Analysis Bipolar Disorder workinggroup, study hippocampal subfield volumetry in BD. T1‐weighted magnetic resonance imaging scans from 4,698 individuals (BD = 1,472, healthy controls [HC] = 3,226) from 23 sites worldwide were processed with FreeSurfer. We used linear mixed‐effects models and mega‐analysis to investigate differences in hippocampal subfield volumes between BD and HC, followed by analyses of clinical characteristics and medication use. BD showed significantly smaller volumes of the whole hippocampus (Cohen's d = −0.20), cornu ammonis (CA)1 (d = −0.18), CA2/3 (d = −0.11), CA4 (d = −0.19), molecular layer (d = −0.21), granule cell layer of dentate gyrus (d = −0.21), hippocampal tail (d = −0.10), subiculum (d = −0.15), presubiculum (d = −0.18), and hippocampal amygdala transition area (d = −0.17) compared to HC. Lithium users did not show volume differences compared to HC, while non‐users did. Antipsychotics or antiepileptic use was associated with smaller volumes. In this largest study of hippocampal subfields in BD to date, we show widespread reductions in nine of 12 subfields studied. The associations were modulated by medication use and specifically the lack of differences between lithium users and HC supports a possible protective role of lithium in BD.

Risk of dementia in bipolar disorder and the interplay of lithium: a systematic review and meta-analyses

OBJECTIVES

To assess whether bipolar disorder (BD) increases the rate of dementia and whether lithium is related to a lower risk of dementia in BD.

METHODS

A total of 10 studies (6859 BD; 487 966 controls) were included in the meta-analysis to test whether BD is a risk factor for dementia. In addition, five studies (6483 lithium; 43 496 non-lithium) were included in the meta-analysis about the potential protective effect of lithium in BD.

RESULTS

BD increases the risk of dementia (odds ratio (OR): 2.96 [95% CI: 2.09-4.18], P < 0.001), and treatment with lithium decreases the risk of dementia in BD (OR: 0.51 [95% CI: 0.36-0.72], P < 0.0001). In addition, secondary findings from our systematic review showed that the risk of progression to dementia is higher in BD than in major depressive disorder (MDD). Moreover, the number of mood episodes predicted the development of dementia in BD.

CONCLUSION

Individuals with BD are at higher risk of dementia than both the general population or those with MDD. Lithium appears to reduce the risk of developing dementia in BD.

Neurodevelopmental pathways in bipolar disorder

Aberrations in neurodevelopmental trajectories have been implicated in the neurobiology of several mental disorders and evidence indicates a pathophysiological and genetic overlap of schizophrenia and bipolar disorder (BD). In this narrative review, we summarize findings related to developmental and perinatal factors as well as epidemiological, clinical, neuropsychological, brain imaging, postmortem brain and genomic studies that provide evidence for a putative neurodevelopmental pathogenesis and etiology of BD. Overall, aberrations in neurodevelopmental pathways have been more consistently implicated in the pathophysiology of schizophrenia compared to BD. Nevertheless, an accumulating body of evidence indicates that dysfunctional neurodevelopmental pathways may be implicated in the underlying pathophysiology of at least a subset of individuals with BD particularly those with an early age of illness onset and those exhibiting psychotic symptoms. A heuristic neurodevelopmental model for the pathophysiology of BD based on the findings of this review is proposed. Furthermore, we critically discuss clinical and research implications of this model. Finally, further research directions for this emerging field are provided.

Current understandings of the trajectory and emerging correlates of cognitive impairment in bipolar disorder: An overview of evidence

OBJECTIVES

Cognitive dysfunction affects a significant proportion of people with bipolar disorder (BD), but the cause, trajectory and correlates of such dysfunction remains unclear. Increased understanding of these factors is required to progress treatment development for this symptom dimension.

METHODS

This paper provides a critical overview of the literature concerning the trajectories and emerging correlates of cognitive functioning in BD. It is a narrative review in which we provide a qualitative synthesis of current evidence concerning clinical, molecular, neural and lifestyle correlates of cognitive impairment in BD across the lifespan (in premorbid, prodromal, early onset, post-onset, elderly cohorts).

RESULTS

There is emerging evidence of empirical links between cognitive impairment and an increased inflammatory state, brain structural abnormalities and reduced neuroprotection in BD. However, evidence regarding the progressive nature of cognitive impairment is mixed, since consensus between different cross-sectional data is lacking and does not align to the outcomes of the limited longitudinal studies available. Increased recognition of cognitive heterogeneity in BD may help to explain some inconsistencies in the extant literature.

CONCLUSIONS

Large, longitudinally focussed studies of cognition and its covariation alongside biological and lifestyle factors are required to better define cognitive trajectories in BD, and eventually pave the way for the application of a precision medicine approach for individual patients in clinical practice.

Molecular Mechanisms Linking ALS/FTD and Psychiatric Disorders, the Potential Effects of Lithium

Altered proteostasis, endoplasmic reticulum (ER) stress, abnormal unfolded protein response (UPR), mitochondrial dysfunction and autophagy impairment are interconnected events, which contribute to the pathogenesis of amyotrophic lateral sclerosis (ALS)/frontotemporal dementia (FTD). In recent years, the mood stabilizer lithium was shown to potentially modify ALS/FTD beyond mood disorder-related pathology. The effects of lithium are significant in ALS patients carrying genetic variations in the UNC13 presynaptic protein, which occur in ALS/FTD and psychiatric disorders as well. In the brain, lithium modulates a number of biochemical pathways involved in synaptic plasticity, proteostasis, and neuronal survival. By targeting UPR-related events, namely ER stress, excitotoxicity and autophagy dysfunction, lithium produces plastic effects. These are likely to relate to neuroprotection, which was postulated for mood and motor neuron disorders. In the present manuscript, we try to identify and discuss potential mechanisms through which lithium copes concomitantly with ER stress, UPR and autophagy dysfunctions related to UNC13 synaptic alterations and aberrant RNA and protein processing. This may serve as a paradigm to provide novel insights into the neurobiology of ALS/FTD featuring early psychiatric disturbances.

Putative neuroprotective pharmacotherapies to target the staged progression of mental illness

AIM

Neuropsychiatric disorders including depression, bipolar and schizophrenia frequently exhibit a neuroprogressive course from prodrome to chronicity. There are a range of agents exhibiting capacity to attenuate biological mechanisms associated with neuroprogression. This review will update the evidence for putative neuroprotective agents including clinical efficacy, mechanisms of action and limitations in current assessment tools, and identify novel agents with neuroprotective potential.

METHOD

Data for this review were sourced from online databases PUBMED, Embase and Web of Science. Only data published since 2012 were included in this review, no data were excluded based on language or publication origin.

RESULTS

Each of the agents reviewed inhibit one or multiple pathways of neuroprogression including: inflammatory gene expression and cytokine release, oxidative and nitrosative stress, mitochondrial dysfunction, neurotrophin dysregulation and apoptotic signalling. Some demonstrate clinical efficacy in preventing neural damage or loss, relapse or cognitive/functional decline. Agents include: the psychotropic medications lithium, second generation antipsychotics and antidepressants; other pharmacological agents such as minocycline, aspirin, cyclooxygenase-2 inhibitors, statins, ketamine and alpha-2-delta ligands; and others such as erythropoietin, oestrogen, leptin, N-acetylcysteine, curcumin, melatonin and ebselen.

CONCLUSIONS

Signals of evidence of clinical neuroprotection are evident for a number of candidate agents. Adjunctive use of multiple agents may present a viable avenue to clinical realization of neuroprotection. Definitive prospective studies of neuroprotection with multimodal assessment tools are required.

Putative Mechanisms of Action and Clinical Use of Lithium in Children and Adolescents: A Critical Review

Background:

Lithium is a first-line treatment for bipolar disorder in adults, but its mechanism of action is still far from clear. Furthermore, evidences of its use in pediatric populations are sparse, not only for bipolar disorders, but also for other possible indications.

Objectives:

To provide a synthesis of published data on the possible mechanisms of action of lithium, as well as on its use in pediatric samples, including pharmacokinetics, efficacy, and safety data.

Methods:

Clinical trials in pediatric samples with at least one standardized measure of efficacy/effectiveness were included in this review. We considered: i) randomized and open label trials, ii) combination studies iii) augmentation studies iv) case series including at least 5 patients.

Results:

Different and non-alternative mechanisms of action can explain the clinical efficacy of lithium. Clinical studies in pediatric samples suggest that lithium is effective in managing manic symptoms/episodes of bipolar disorder, both in the acute phase and as maintenance strategy. Efficacy on depressive symptoms/phases of bipolar disorder is much less clear, while studies do not support its use in unipolar depression and severe mood dysregulation. Conversely, it may be effective on aggression in the context of conduct disorder. Other possible indications, with limited published evidence, are the acute attacks in Kleine-Levin syndrome, behavioral symptoms of X-fragile syndrome, and the management of clozapine- or chemotherapy- induced neutropenia. Generally, lithium resulted relatively safe.

Conclusions:

Lithium seems an effective and well-tolerated medication in pediatric bipolar disorder and aggression, while further evidences are needed for other clinical indications.

White matter microstructural properties in bipolar disorder in relationship to the spatial distribution of lithium in the brain

BACKGROUND

Lithium treatment is associated with an increase in magnetic resonance imaging derived measures of white matter integrity, but the relationship between the spatial distribution of brain lithium and white matter integrity is unknown.

METHODS

Euthymic patients with bipolar disorder receiving lithium (n = 12) and those on other medications but naïve to lithium (n = 17) underwent diffusion imaging alongside matched healthy controls (n = 16). Generalised fractional anisotropy (gFA) within white matter was compared between groups using a standard space white matter atlas. Lithium-treated patients underwent novel multinuclear lithium magnetic resonance imaging (⁷Li-MRI) to determine the relative lithium concentration across the brain. The relationship between ⁷Li-MRI signal intensity and gFA was investigated at the resolution of the ⁷Li-MRI sequence in native space.

RESULTS

Lithium-treated bipolar disorder and healthy control groups had higher mean white matter gFA than the bipolar disorder group treated with other medications (t = 2.5, p < 0.05; t = 2.7, p < 0.03, respectively). No differences in gFA were found between patients taking lithium and healthy controls (t = 0.02, p = 1). These effects were seen consistently across most regions in the white matter atlas. In the lithium-treated group, a significant effect of the ⁷Li-MRI signal in predicting the gFA (p < 0.01) was identified in voxels containing over 50% white matter.

LIMITATIONS

Cross-sectional evaluation of a relatively small cohort.

CONCLUSIONS

The higher gFA values observed in the lithium-treated bipolar disorder group suggests that long-term lithium is associated with greater white matter integrity. Our novel analysis supports this further, showing a positive association between white matter gFA and the spatial distribution of lithium.

Bipolar and psychotic disorders in elite athletes: a narrative review

Bipolar and psychotic disorders are relatively common and likely to have a significant impact on quality of life and functioning which, in the context of elite sport, includes a potential negative impact on sporting performance. For this narrative review article, the literature on bipolar and psychotic disorders in elite athletes was comprehensively searched, and little empirical research was found. A diagnosis of bipolar or psychotic disorders may be challenging in elite athletes because of complicating factors related to the modifying role of exercise and potential precipitating impact of substance use. Medications used to treat bipolar and psychotic disorders may have side effects particularly problematic for elite athletes. Future research should be tailored to the specific characteristics and needs of elite athletes and to the sporting context in which the disorders may arise. Specifically, further research is needed on the prevalence and incidence of these conditions in elite athletes and the impact of both the disorders and their treatments on sporting performance.

What specifically contributes to disturbed non-verbal fluency in patients with bipolar disorder: Ineffective performance initiation, slowed processing or lack of the execution strategy?

The study aimed at identifying the cognitive and clinical determinants of impaired design fluency in bipolar patients, with special reference to processing speed and performance strategy. A sample of bipolar disorder patients (BD, n = 45) and matched healthy controls (HC, n = 42) underwent the assessment of figural fluency, cognitive and manual speed, cognitive effort and affective state. An electronic version of design fluency test was applied, enabling assessment of performance speed, execution strategy and spontaneous fluctuations in production efficiency. Additional clinical variables were also controlled. BD patients produced significantly less unique designs, performed slower, utilized less effective strategy, their ability to concentrate designs production in the initial phase of performance was significantly reduced compared with HC. Regression analysis revealed that in BD patients design fluency main outcome was significantly predicted by slowed creation of designs and the number of hospitalizations, while in the HC group, the main fluency result was predicted only by the executive strategy indicators. Our study showed that non-verbal fluency in BD group was determined by essentially different neuropsychological functions than in healthy controls. Obtained findings confirm that cognitive slowdown should be an important goal of cognitive remediation and pharmacological interventions in bipolar disorder.

Challenging the Negative Perception of Lithium and Optimizing Its Long-Term Administration

The use of lithium for the prevention of recurrences in mood disorders has a 55-year history. Nowadays, lithium is universally accepted as the first-choice mood-stabilizer (MS) for maintenance treatment of bipolar disorder. In addition to its mood-stabilizing properties, lithium exerts anti-suicidal, immunomodulatory and neuroprotective action which may further substantiate its clinical usefulness. Despite these facts, the use of lithium in mood disorders has been greatly underutilized. The reasons include the introduction and promoting other MS as well as a perception of lithium as a “toxic drug” due to its side effects, mainly thyroid, renal and cognitive disturbances. The trends in lithium prescription in recent decades show relative stability or a decline at the expense of other mood-stabilizing drugs, both first generation (valproate) and second generation (olanzapine, quetiapine, lamotrigine). In this review article, the negative perception of lithium by some clinicians will be challenged. First, the data showing lithium superiority over other MS will be presented. Second, the lithium-induced side effects which can make a challenge for a more frequent application of this drug will be delineated, and their proper management described. Finally, an issue of benefits of long-term administration of lithium will be discussed, including the phenomenon of the “excellent lithium responders” (ER) as well as a subject of starting lithium prophylaxis early in the course of the illness. This review article is based on the 47-year experience with lithium therapy by the author of the article.

Differential effect of quetiapine and lithium on functional connectivity of the striatum in first episode mania

Mood disturbances seen in first-episode mania (FEM) are linked to disturbed functional connectivity of the striatum. Lithium and quetiapine are effective treatments for mania but their neurobiological effects remain largely unknown. We conducted a single-blinded randomized controlled maintenance trial in 61 FEM patients and 30 healthy controls. Patients were stabilized for a minimum of 2 weeks on lithium plus quetiapine then randomly assigned to either lithium (serum level 0.6 mmol/L) or quetiapine (dosed up to 800 mg/day) treatment for 12 months. Resting-state fMRI was acquired at baseline, 3 months (patient only) and 12 months. The effects of treatment group, time and their interaction, on striatal functional connectivity were assessed using voxel-wise general linear modelling. At baseline, FEM patients showed reduced connectivity in the dorsal (p = 0.05) and caudal (p = 0.008) cortico-striatal systems when compared to healthy controls at baseline. FEM patients also showed increased connectivity in a circuit linking the ventral striatum with the medial orbitofrontal cortex, cerebellum and thalamus (p = 0.02). Longitudinally, we found a significant interaction between time and treatment group, such that lithium was more rapid, compared to quetiapine, in normalizing abnormally increased functional connectivity, as assessed at 3-month and 12-month follow-ups. The results suggest that FEM is associated with reduced connectivity in dorsal and caudal corticostriatal systems, as well as increased functional connectivity of ventral striatal systems. Lithium appears to act more rapidly than quetiapine in normalizing hyperconnectivity of the ventral striatum with the cerebellum. The study was registered on the Australian and New Zealand Clinical Trials Registry (ACTRN12607000639426). http://www.anzctr.org.au.

Neuron-glia Interaction as a Possible Pathophysiological Mechanism of Bipolar Disorder

Accumulating evidence has shown the importance of glial cells in the neurobiology of bipolar disorder. Activated microglia and inflammatory cytokines have been pointed out as potential biomarkers of bipolar disorder. Indeed, recent studies have shown that bipolar disorder involves microglial activation in the hippocampus and alterations in peripheral cytokines, suggesting a potential link between neuroinflammation and peripheral toxicity. These abnormalities may also be the biological underpinnings of outcomes related to neuroprogression, such as cognitive impairment and brain changes. Additionally, astrocytes may have a role in the progression of bipolar disorder, as these cells amplify inflammatory response and maintain glutamate homeostasis, preventing excitotoxicity. The present review aims to discuss neuron-glia interactions and their role in the pathophysiology and treatment of bipolar disorder.

Staging in bipolar disorder: from theoretical framework to clinical utility

Illness staging is widely utilized in several medical disciplines to help predict course or prognosis, and optimize treatment. Staging models in psychiatry in general, and bipolar disorder in particular, depend on the premise that psychopathology moves along a predictable path: an at-risk or latency stage, a prodrome progressing to a first clinical threshold episode, and one or more recurrences with the potential to revert or progress to late or end-stage manifestations. The utility and validity of a staging model for bipolar disorder depend on its linking to clinical outcome, treatment response and neurobiological measures. These include progressive biochemical, neuroimaging and cognitive changes, and potentially stage-specific differences in response to pharmacological and psychosocial treatments. Mechanistically, staging models imply the presence of an active disease process that, if not remediated, can lead to neuroprogression, a more malignant disease course and functional deterioration. Biological elements thought to be operative in bipolar disorder include a genetic diathesis, physical and psychic trauma, epigenetic changes, altered neurogenesis and apoptosis, mitochondrial dysfunction, inflammation, and oxidative stress. Many available agents, such as lithium, have effects on these targets. Staging models also suggest the utility of stage-specific treatment approaches that may not only target symptom reduction, but also impede illness neuroprogression. These treatment approaches range from prevention for at-risk individuals, to early intervention strategies for prodromal and newly diagnosed individuals, complex combination therapy for rapidly recurrent illness, and palliative-type approaches for those at chronic, late stages of illness. There is hope that prompt initiation of potentially disease modifying therapies may preclude or attenuate the cognitive and structural changes seen in the later stages of bipolar disorder. The aims of this paper are to: a) explore the current level of evidence supporting the descriptive staging of the syndromal pattern of bipolar disorder; b) describe preliminary attempts at validation; c) make recommendations for the direction of further studies; and d) provide a distillation of the potential clinical implications of staging in bipolar disorder within a broader transdiagnostic framework.

Longitudinal investigation of the parietal lobe anatomy in bipolar disorder and its association with general functioning

The parietal lobe (PL) supports cognitive domains, including attention and memory, which are impaired in bipolar disorder (BD). Although cross-sectional voxel-based morphometry studies found reduced PL grey matter (GM) in BD, none has longitudinally focused on PL anatomy in BD, relating it to patients' functioning. Thirty-eight right-handed BD patients and 42 matched healthy subjects (HS) underwent a Magnetic Resonance Imaging (MRI) scan at baseline. Seventeen BD patients and 16 matched HS underwent a follow-up MRI. PL white matter (WM) and GM volumes were measured. The trajectory of parietal volumes over time and the possible relation with the global functioning were investigated in both BD patients and HS. At baseline, BD patients showed significant reduced PL WM and GM and different WM laterality compared with HS. Furthermore, smaller PL WM volumes predicted lower global functioning in BD, but not in HS. At follow-up, although BD patients reported reduced PL WM compared with HS, no different pattern of volume changes over time was detected between groups. This study suggests the involvement of the PL in the pathophysiology of BD. In particular, PL WM reductions seem to predict an impairment in general functioning in BD and might represent a marker of functional outcome.