Early improvement of psychotic symptoms with lithium monotherapy as a predictor of later response in mania

All studies are not created equal: A systematic narrative review of bipolar depression clinical trial inclusion/exclusion rules and baseline severity scores

BACKGROUND

Several bipolar depression treatment guidelines have been designed to assist clinicians with medication selection. When ranking medications, none explicitly considered the inclusion/exclusion criteria or baseline severity scores of the reviewed clinical trials. This article aimed to determine if sufficient differences exist in these variables to justify their consideration when designing treatment guidelines.

METHODS

Using Ovid and PubMed databases in May and September 2022, all published, short-term cross-over or parallel-group design studies comparing second generation antipsychotics (SGAs), mood stabilizers, or antidepressants versus placebo in bipolar depressed patients were identified. Included studies must have enrolled adult bipolar I/II depressed patients, randomized patients into two or more treatment groups, utilized a double-blind, prospective design written in English, and had primary outcome results that were statistically significant in favor of the investigational treatment.

RESULTS

Thirty studies met eligibility criteria, comprising a total of 8791 patients. Among those studies, there were seventeen antipsychotic trials, six lithium trials, one lamotrigine trial, three valproate trials, two carbamazepine trials, and two antidepressant trials. The analysis revealed substantial differences among the studies. Although this was seen among all the different drug classes, these differences are clearest when comparing the lithium trials to those of the SGAs.

LIMITATIONS

Limitations included the selection of severity scores from the treatment arm with the most severe score and the exclusive focus on mood stabilizers, antidepressants, and SGAs.

CONCLUSIONS

Severity of the enrolled patient sample and treatment-resistance should be considered in addition to other factors when ranking medications in bipolar depression treatment guidelines.

Psychotic symptoms in bipolar disorder and their impact on the illness: A systematic review

BACKGROUND

Lifetime psychotic symptoms are present in over half of the patients with bipolar disorder (BD) and can have an adverse effect on its course, outcome, and treatment. However, despite a considerable amount of research, the impact of psychotic symptoms on BD remains unclear, and there are very few systematic reviews on the subject.

AIM

To examine the extent of psychotic symptoms in BD and their impact on several aspects of the illness.

METHODS

The Preferred Reporting Items for Systematic Reviews and Meta-analyses guidelines were followed. An electronic literature search of six English-language databases and a manual search was undertaken to identify published articles on psychotic symptoms in BD from January 1940 to December 2021. Combinations of the relevant Medical Subject Headings terms were used to search for these studies. Articles were selected after a screening phase, followed by a review of the full texts of the articles. Assessment of the methodological quality of the studies and the risk of bias was conducted using standard tools.

RESULTS

This systematic review included 339 studies of patients with BD. Lifetime psychosis was found in more than a half to two-thirds of the patients, while current psychosis was found in a little less than half of them. Delusions were more common than hallucinations in all phases of BD. About a third of the patients reported first-rank symptoms or mood-incongruent psychotic symptoms, particularly during manic episodes. Psychotic symptoms were more frequent in bipolar type I compared to bipolar type II disorder and in mania or mixed episodes compared to bipolar depression. Although psychotic symptoms were not more severe in BD, the severity of the illness in psychotic BD was consistently greater. Psychosis was usually associated with poor insight and a higher frequency of agitation, anxiety, and hostility but not with psychiatric comorbidity. Psychosis was consistently linked with increased rates and the duration of hospitalizations, switching among patients with depression, and poorer outcomes with mood-incongruent symptoms. In contrast, psychosis was less likely to be accompanied by a rapid-cycling course, longer illness duration, and heightened suicidal risk. There was no significant impact of psychosis on the other parameters of course and outcome.

CONCLUSION

Though psychotic symptoms are very common in BD, they are not always associated with an adverse impact on BD and its course and outcome.

Guidelines for the management of psychosis in the context of mood disorders

Psychotic episodes occur in a substantial proportion of patients suffering from major mood disorders (both unipolar and bipolar) at some point in their lives. The nature of these episodes is less well understood than the more common, non-psychotic periods of illness and hence their management is also less sophisticated. This is a concern because the risk of suicide is particularly high in this subtype of mood disorder and comorbidity is far more common. In some cases psychotic symptoms may be signs of a comorbid illness but the relationship of psychotic mood to other forms of psychosis and in particular its interactions with schizophrenia is poorly understood. Therefore, our targeted review draws upon extant research and our combined experience to provide clinical context and a framework for the management of these disorders in real-world practice - taking into consideration both biological and psychological interventions.

Psychotic Depression: Diagnosis, Differential Diagnosis, and Treatment

Psychotic depression was initially considered to be at one end of a continuum of severity of major depression. Subsequent experience demonstrated that psychosis is an independent trait that may accompany mood disorders of varying severity. While much has been learned about the impact of severe mood congruent delusions and hallucinations on the course and treatment response of depression, less is known about fleeting or mild psychosis, mood incongruent features, or psychotic symptoms that reflect traumatic experiences. Acute treatment of psychotic unipolar depression generally involves the combination of an antidepressant and an antipsychotic drug or electroconvulsive therapy. There is inadequate information about maintenance treatment of unipolar psychotic depression and acute and chronic treatment of psychotic bipolar disorder. Decision-making therefore still must rely in part on clinical experience.

Pharmacogenomics of Lithium Response in Bipolar Disorder

Despite being the most widely studied mood stabilizer, researchers have not confirmed a mechanism for lithium’s therapeutic efficacy in Bipolar Disorder (BD). Pharmacogenomic applications may be clinically useful in the future for identifying lithium-responsive patients and facilitating personalized treatment. Six genome-wide association studies (GWAS) reviewed here present evidence of genetic variations related to lithium responsivity and side effect expression. Variants were found on genes regulating the glutamate system, including GAD-like gene 1 (GADL1) and GRIA2 gene, a mutually-regulated target of lithium. In addition, single nucleotide polymorphisms (SNPs) discovered on SESTD1 may account for lithium’s exceptional ability to permeate cell membranes and mediate autoimmune and renal effects. Studies also corroborated the importance of epigenetics and stress regulation on lithium response, finding variants on long, non-coding RNA genes and associations between response and genetic loading for psychiatric comorbidities. Overall, the precision medicine model of stratifying patients based on phenotype seems to derive genotypic support of a separate clinical subtype of lithium-responsive BD. Results have yet to be expounded upon and should therefore be interpreted with caution.

Factors predicting re-hospitalization for inpatients with bipolar mania--A naturalistic cohort

Patients with bipolar mania often require re-hospitalization, which can be a social-economic burden. This study aimed to investigate the factors affecting time to re-hospitalization for inpatients with acute bipolar mania. In this 6-year naturalistic study we reviewed the charts of inpatients with acute bipolar mania. Potential dichotomous factors including sex, family history of affective disorder, suicide history, and discharge against medical advice, involuntary admission, psychotic features, substance use disorder, and remission at discharge were recorded. Continuous variables including age, age at onset of affective episodes, and number of previous hospitalizations were also recorded. We used survival analysis with a univariate Cox proportional hazard regression model, along with forward multivariate model, to identify the potential factors. Of the 165 patients, 23% achieved symptomatic remission at discharge. In the forward Cox model, psychotic features, discharge against medical advice and higher number of previous hospitalizations were significant risk factors for re-admission. Remission at discharge was significantly associated with preventing re-hospitalization. We identified several predictors for re-hospitalization among inpatients with bipolar mania. Further studies are needed in other real-world settings to validate our results.

Lithium levels in tap water and psychotic experiences in a general population of adolescents

Recently, several epidemiologic studies have reported that lithium in drinking water may be associated with lower rates of suicide mortality, lower incidence of dementia, and lower levels of adolescents' depression and aggression at the population level. However, to our knowledge, no study has investigated lithium level in tap water in relation to psychotic experiences in a general population of adolescents. This is the first study to investigate this using a large dataset. Information on psychotic experiences, distress associated with these experiences, and depressive symptoms were collected in 24 public junior high schools in Kochi Prefecture in Japan. Samples were collected from sources that supplied drinking water to schools, and lithium levels were measured using atomic absorption spectrophotometry. The association of lithium levels with psychotic experiences, considering distress as a degree of severity, was examined using an ordinal logistic regression model with schools and depressive symptoms as random effects. In total, 3040 students responded to the self-reporting questionnaire (response rate: 91.8%). Lithium levels in tap water were inversely associated with psychotic experiences (p = 0.021). We concluded that lithium level in tap water was inversely associated with psychotic experiences among a general population of adolescents and may have a preventive effect for such experiences and distress.

Lithium, Stress, and Resilience in Bipolar Disorder: Deciphering this key homeostatic synaptic plasticity regulator

BACKGROUND

Lithium is the lightest metal and the only mood stabilizer that has been used for over half a century for the treatment of bipolar disorder (BD). As a small ion, lithium is omnipresent, and consequently, its molecular mechanisms and targets are widespread. Currently, lithium is a crucial pharmacotherapy for the treatment of acute mood episodes, prophylactic therapy, and suicide prevention in BD. Besides, lithium blood level is the most widely used biomarker in clinical psychiatry. The concept of stress in BD characterizes short- and long-term deleterious effects at multiple levels (from genes to behaviors) and the ability to establish homeostatic regulatory mechanisms to either prevent or reverse these effects. Within this concept, lithium has consistently shown anti-stress effects, by normalizing components across several levels associated with BD-induced impairments in cellular resilience and plasticity.

METHODS

A literature search for biomarkers associated with lithium effects at multiple targets, with a particular focus on those related to clinical outcomes was performed. An extensive search of the published literature using PubMed, Medline and Google Scholar was performed. Example search terms included lithium, plasticity, stress, efficacy, and neuroimaging. Articles determined by the author to focus on lithium's impact on neural plasticity markers (central and periphery) and clinical outcomes were examined in greater depth. Relevant papers were evaluated, selected and included in this review.

RESULTS

Lithium induces neurotrophic and neuroprotective effects in a wide range of preclinical and translational models. Lithium's neurotrophic effects are related to the enhancement of cellular proliferation, differentiation, growth, and regeneration, whereas its neuroprotective effects limit the progression of neuronal atrophy or cell death following the onset of BD. Lithium's neurotrophic and neuroprotective effects seem most pronounced in the presence of pathology, which again supports its pivotal role as an active homeostatic regulator.

LIMITATIONS

Few studies associated with clinical outcomes. Due to space limitations, the author was unable to detail all findings, in special those originated from preclinical studies.

CONCLUSIONS

These results support a potential role for biomarkers involved in neuroprotection and activation of plasticity pathways in lithium's clinical response. Evidence supporting this model comes from results evaluating macroscopic and microscopic brain structure as well neurochemical findings in vivo from cellular to sub-synaptic (molecules and intracellular signaling) compartments using central and peripheral biomarkers. Challenges to precisely decipher lithium's biological mechanisms involved in its therapeutic profile include the complex nature of the illness and clinical subtypes, family history and comorbid conditions. In the context of personalized medicine, it is necessary to validate predictive biomarkers of response to lithium by designing longitudinal clinical studies during mood episodes and associated clinical dimensions in BD.

Association of Polygenic Score for Schizophrenia and HLA Antigen and Inflammation Genes With Response to Lithium in Bipolar Affective Disorder: A Genome-Wide Association Study

IMPORTANCE

Lithium is a first-line mood stabilizer for the treatment of bipolar affective disorder (BPAD). However, the efficacy of lithium varies widely, with a nonresponse rate of up to 30%. Biological response markers are lacking. Genetic factors are thought to mediate treatment response to lithium, and there is a previously reported genetic overlap between BPAD and schizophrenia (SCZ).

OBJECTIVES

To test whether a polygenic score for SCZ is associated with treatment response to lithium in BPAD and to explore the potential molecular underpinnings of this association.

DESIGN, SETTING, AND PARTICIPANTS

A total of 2586 patients with BPAD who had undergone lithium treatment were genotyped and assessed for long-term response to treatment between 2008 and 2013. Weighted SCZ polygenic scores were computed at different P value thresholds using summary statistics from an international multicenter genome-wide association study (GWAS) of 36 989 individuals with SCZ and genotype data from patients with BPAD from the Consortium on Lithium Genetics. For functional exploration, a cross-trait meta-GWAS and pathway analysis was performed, combining GWAS summary statistics on SCZ and response to treatment with lithium. Data analysis was performed from September 2016 to February 2017.

MAIN OUTCOMES AND MEASURES

Treatment response to lithium was defined on both the categorical and continuous scales using the Retrospective Criteria of Long-Term Treatment Response in Research Subjects with Bipolar Disorder score. The effect measures include odds ratios and the proportion of variance explained.

RESULTS

Of the 2586 patients in the study (mean [SD] age, 47.2 [13.9] years), 1478 were women and 1108 were men. The polygenic score for SCZ was inversely associated with lithium treatment response in the categorical outcome, at a threshold P < 5 × 10-2. Patients with BPAD who had a low polygenic load for SCZ responded better to lithium, with odds ratios for lithium response ranging from 3.46 (95% CI, 1.42-8.41) at the first decile to 2.03 (95% CI, 0.86-4.81) at the ninth decile, compared with the patients in the 10th decile of SCZ risk. In the cross-trait meta-GWAS, 15 genetic loci that may have overlapping effects on lithium treatment response and susceptibility to SCZ were identified. Functional pathway and network analysis of these loci point to the HLA antigen complex and inflammatory cytokines.

CONCLUSIONS AND RELEVANCE

This study provides evidence for a negative association between high genetic loading for SCZ and poor response to lithium in patients with BPAD. These results suggest the potential for translational research aimed at personalized prescribing of lithium.

An Oldie but Goodie: Lithium in the Treatment of Bipolar Disorder through Neuroprotective and Neurotrophic Mechanisms

Lithium has been used for the treatment of bipolar disorder (BD) for the last sixty or more years, and recent studies with more reliable designs and updated guidelines have recommended lithium to be the treatment of choice for acute manic, mixed and depressive episodes of BD, along with long-term prophylaxis. Lithium’s specific mechanism of action in mood regulation is progressively being clarified, such as the direct inhibition on glycogen synthase kinase 3β, and its various effects on neurotrophic factors, neurotransmitters, oxidative metabolism, apoptosis, second messenger systems, and biological systems are also being revealed. Furthermore, lithium has been proposed to exert its treatment effects through mechanisms associated with neuronal plasticity. In this review, we have overviewed the clinical aspects of lithium use for BD, and have focused on the neuroprotective and neurotrophic effects of lithium.

Early Improvement Predicts Treatment Outcomes for Patients With Acute Mania: A Naturalistic Study in Taiwan

BACKGROUND

Bipolar disorder is a serious mental disorder. This study investigated whether early improvement at week 1 or 2 could predict treatment outcomes at week 4 in clinical populations with acute mania.

METHODS

We conducted a naturalistic study, recruiting inpatients with bipolar mania for acute treatment. Symptom severity was assessed using the Young Mania Rating Scale (YMRS) at weeks 0, 1, 2, 3, and 4. Early improvement was defined as a reduction in the YMRS score of at least 20% or 25%, assessed at weeks 1 and 2. Response was defined as a reduction of 50% or more in the YMRS score, and remission was defined as an end-point YMRS score of 12 or less. Receiver operating characteristic curves were used to determine whether week 1 or week 2 had better discriminative capacity. Sensitivity, specificity, and predictive values were calculated for the different definitions of early improvement.

RESULTS

Of the 350 patients, 32.9% (n = 115) and 16.6% (n = 58) of the subjects were classified as responders and remitters at week 4, respectively. Early improvement at week 2 showed better discriminative capacity, with areas under the receiver operating characteristic curve greater than 0.8. It had high sensitivity and high negative predictive value for 2 cutoffs in predicting response and remission.

CONCLUSIONS

Relatively lower response and remission rates were observed. Response and remission could be predicted by early improvement at week 2, whereas patients without early improvement were unlikely to reach response and remission at week 4.