An examination of the quality and performance of the Alda scale for classifying lithium response phenotypes

OBJECTIVES

The Retrospective Assessment of the Lithium Response Phenotype Scale (Alda scale) is the most widely used clinical measure of lithium response phenotypes. We assess its performance against recommended psychometric and clinimetric standards.

METHODS

We used data from the Consortium for Lithium Genetics and a French study of lithium response phenotypes (combined sample >2500) to assess reproducibility, responsiveness, validity, and interpretability of the A scale (assessing change in illness activity), the B scale, and its items (assessing confounders of response) and the previously established response categories derived from the Total Score for the Alda scale.

RESULTS

The key findings are that the B scale is vulnerable to error measurement. For example, some items contribute little to overall performance of the Alda scale (eg, B2) and that the B scale does not reliably assess a single construct (uncertainty in response). Machine learning models indicate that it may be more useful to employ an algorithm for combining the ratings of individual B items in a sequence that clarifies the noise to signal ratio instead of using a composite score.

CONCLUSIONS

This study highlights three important topics. First, empirical approaches can help determine which aspects of the performance of any scale can be improved. Second, the B scale of the Alda is best applied as a multidimensional index (identifying several independent confounders of the assessment of response). Third, an integrated science approach to precision psychiatry is vital, otherwise phenotypic misclassifications will undermine the reliability and validity of findings from genetics and biomarker studies.

Long-term response to mood stabilizer treatment and its clinical correlates in patients with bipolar disorders: a retrospective observational study

BACKGROUND

The efficacy and utility of long-term prophylactic treatment in patients with bipolar disorders (BDs) have not been fully explored. This study aims to estimate the long-term clinical response of patients with BDs to mood stabilizer treatment and to identify the clinical factors associated with that response.

METHODS

The study subjects consisted of 80 patients with bipolar I or bipolar II disorder who had been receiving treatment with lithium and/or valproate for more than 2 years at a single bipolar disorder clinic. The long-term response to the best treatment option based on treatment algorithms was evaluated using the Alda scale. Clinical characteristics were evaluated on a lifetime basis. Patients were classified into two response groups based on frequentist mixture analysis using the total Alda scale score.

RESULTS

Thirty-four percent of the patients were good responders, with a total Alda score of 5 or higher. The treatment response rate did not differ between the lithium and valproate groups, but lithium and valproate combination therapy was associated with poorer response. The number of previous mixed episodes was associated with a worse response (p = 0.026). Of individual symptoms, delusions during manic episodes (p = 0.008) and increased appetite (p = 0.035) during depressive episodes were more common in moderate/poor responders than in good responders. Co-morbid anxiety disorders were more frequently observed in the moderate/poor response group (p = 0.008).

CONCLUSIONS

Psychotic, mixed, and atypical features of BDs were found to be correlated with long-term treatment outcomes. Lithium and valproate showed similar efficacy but moderate/poor responders preferred to use polypharmacy.

Cross-validation of clinical characteristics and treatment patterns associated with phenotypes for lithium response defined by the Alda scale

BACKGROUND

It is increasingly recognised that reliable and valid assessments of lithium response are needed in order to target more efficiently the use of this medication in bipolar disorders (BD) and to identify genotypes, endophenotypes and biomarkers of response.

METHODS

In a large, multi-centre, clinically representative sample of 300 cases of BD, we assess external clinical validators of lithium response phenotypes as defined using three different recommended approaches to scoring the Alda lithium response scale. The scale comprises an A scale (rating lithium response) and a B scale (assessing confounders).

RESULTS

Analysis of the two continuous scoring methods (A scale score minus the B scale score, or A scale score in those with a low B scale score) demonstrated that 21-23% of the explained variance in lithium response was accounted for by a positive family history of BD I and the early introduction of lithium. Categorical definitions of response suggest poor response is also associated with a positive history of alcohol and/or substance use comorbidities. High B scale scores were significantly associated with longer duration of illness prior to receiving lithium and the presence of psychotic symptoms.

LIMITATIONS

The original sample was not recruited specifically to study lithium response. The Alda scale is designed to assess response retrospectively.

CONCLUSIONS

This cross-validation study identifies different clinical phenotypes of lithium response when defined by continuous or categorical measures. Future clinical, genetic and biomarker studies should report both the findings and the method employed to assess lithium response according to the Alda scale.

Defining phenotypes of long-term lithium and valproate response, including combination therapy: a modified application of the Alda scale in patients with bipolar disorders

BACKGROUND

When evaluating the long-term treatment response to mood stabilizers using the Alda scale, mood stabilizer combination therapy is typically considered a confounding factor, and patients receiving combination therapy are excluded from the analysis. However, this may result in bias if those under combination therapy are worse treatment responders. This study aims to explore whether the Alda scale is applicable to patients taking lithium and valproate combination therapy. We compared long-term treatment response in patients receiving monotherapy and combination therapy of the two drugs, and investigated clinical correlates of the responses to each drug.

METHODS

The study subjects consisted of 102 patients with bipolar I (BD-I) or bipolar II (BD-II) disorder who had been undergoing maintenance treatment with lithium and/or valproate for more than 2 years at a single specialized bipolar disorder clinic. Long-term treatment response was measured using the Alda scale and compared among the lithium monotherapy group, the valproate monotherapy group, and the mood stabilizer combination group. Clinical correlates of long-term treatment response were evaluated in lithium users and valproate users separately.

RESULTS

There were no significant differences in terms of baseline illness characteristics among groups. The combination group showed the worst treatment response for all the response measurements applied. This group also had the higher rate of 'poor responder' with a statistically significant difference compared to valproate group. Older age at onset and (hypo)manic episode at onset showed significant positive associations with total Alda score in lithium users, while comorbid anxiety disorders, obsessive-compulsive disorder and mixed episode showed significant negative associations in valproate users.

CONCLUSIONS

The combination group had poorer long-term treatment response but did not show distinct clinical characteristics compared to the monotherapy groups. When exploring the long-term effects of mood stabilizers, excluding patients undergoing combination treatment could result in bias because they may represent a poor response group. The long-term treatment responses of lithium and valproate had different clinical correlates.

Cognitive function, treatment response to lithium, and social functioning in Japanese patients with bipolar disorder

OBJECTIVES

Patients with bipolar disorder often suffer from cognitive impairment that significantly influences their functional outcome. However, it remains unknown whether lithium has a central role in cognition and functional outcome. We examined whether cognition and functional outcome were predicted by demographic and clinical variables, including the response to lithium, in lithium-treated patients with bipolar disorder.

METHODS

We evaluated 96 lithium-treated euthymic patients with bipolar disorder and 196 age- and-gender-matched healthy controls, using the Brief Assessment of Cognition in Schizophrenia (BACS). The patients were also assessed using the Social Functioning Scale (SFS) and "The Retrospective Criteria of Long-Term Treatment Response in Research Subjects with Bipolar Disorder" (Alda) scale, which was evaluated as either a continuous measure of the total scale or a dichotomous criterion.

RESULTS

Multiple regression analysis revealed two key findings: first, that the premorbid intelligence quotient, age, and number of mood episodes were predictors of the BACS composite score; and, second, that the BACS composite score, negative symptoms, and continuous measure on the total Alda scale (but not its dichotomy) predicted the total SFS score. Structural equation modeling (SEM) was used to confirm these findings, and additionally revealed that the Alda scale was significantly associated with negative symptoms and also the number of mood episodes, regardless of how it was evaluated.

CONCLUSIONS

SEM delineated how demographic and clinical variables, cognitive performance, and response to lithium treatment were causally associated with, and converged on, social function. The putative role of the Alda scale for social function warrants further study.

Impact of sex and complex PTSD comorbidity on pharmacological treatment response in bipolar disorder patients

BACKGROUND

The prevalence of bipolar disorder (BD) is similar in men and women. However, factors such as sex and comorbid psychiatric conditions can influence its clinical presentation and treatment outcomes, including complex PTSD (cPTSD), a newly categorized trauma-related condition. Little is known about how sex and cPTSD comorbidity affect the response to mood stabilizers, a cornerstone treatment for BD. This observational, cross-sectional study examines the impact of sex and cPTSD comorbidity on clinical and behavioral BD features as well as their interplay in influencing pharmacological treatment response.

METHODS

A cohort of BD patients (females = 177, males = 166, age range: 19-76; BD-I = 253, BD-II = 90) was recruited over three years. Clinical assessments were conducted, and patients were administered the International Trauma Questionnaire to evaluate cPTSD comorbidity and the Alda Scale to assess response to mood stabilizers.

RESULTS

Our results show distinct clinical profiles based on sex and cPTSD. Female BD patients exhibit more hypomanic episodes, antidepressant-induced mania, and longer periods of untreated illness than males. Comorbid cPTSD was diagnosed in 154 patients (44.8 %), among which 69 were females. Patients with cPTSD display more severe BD symptoms, including earlier onset, more frequent episodes, and a higher prevalence of psychosis and suicidality. Importantly, comorbid cPTSD was associated with poorer mood stabilizer response, particularly in males, who otherwise responded better to treatment than females.

CONCLUSIONS

These findings underscore the importance of addressing trauma symptoms in BD treatment and highlight the need for individualized approaches considering both sex and comorbid trauma, as standard mood stabilizers may be insufficient for certain subgroups.

The Potential of Using Screening Tools for Bipolar Disorder to Predict Lithium Response

Background/Objectives: Lithium is the gold standard for treating Bipolar Disorder (BD), but its effectiveness varies widely. While clinical and environmental factors may influence response, it remains unclear if screening tools can reliably predict lithium response outcomes. This study explores this potential using two widely used screening instruments for BD. Methods: A total of 146 patients with BD were evaluated. Lithium response was assessed using the Alda Scale, while hypomanic and manic symptoms were characterized through the Hypomania Checklist-32 (HCL-32) and the Mood Disorder Questionnaire (MDQ). Group differences in HCL-32 and MDQ scores were analyzed using ANOVA, and a multivariate model was employed to identify predictors of lithium response. Results: Of the total sample, 46 (31.5%) patients were identified as lithium responders based on the Alda Scale. Responders exhibited significantly higher HCL-32 scores compared to non-responders (p = 0.023), while no differences were observed in MDQ scores or other sociodemographic characteristics. Linear regression analysis revealed that HCL-32 scores were a significant predictor of Alda Scale scores, with no associations found for age, gender, or MDQ scores. Conclusions: Our study underscores the importance of considering hypomanic symptoms when estimating lithium response in BD, particularly by utilizing the HCL-32 during screening.