AN ANALYSIS ON THE SEQUENTIAL CHANGES IN MOOD SYMPTOMS AMONG INPATIENTS WITH BIPOLAR SPECTRUM DISORDER USING PSYCHOMETRIC SCALE SCORES
Authors: Ozaki *Takashi , Narita Hisashi , Mito Shizuka , Udo Niki , Mitsui Nobuyuki , Hashimoto Naoki , Kusumi Ichiro 
Published: February 2025

Abstract

Background
The bipolar disorder spectrum describes a continuum of symptoms comprising a complex range of bipolar subtypes which includes from purely depressive to purely manic symptoms. Modern psychiatric classifications have categorized this spectrum as mood disorders, often leading clinicians to perceive depressive and manic symptoms as residing at opposite ends of the spectrum. Some researchers believe that rather than mood changes, changes in energy and motor activity are the vital symptoms in mania and depression. This multi-dimensionality and heterogeneity within the bipolar disorder spectrum pose significant challenges for understanding its illness course and making clinical decisions. Efforts to address this problem by finding an appropriate models and seeking promising prognostic factors such as symptoms profiles, biomarkers, and epidemiological information have ended in limited success. Given the intricate interplay between these symptoms, elucidating the antecedent factors and illness course variables for bipolar spectrum disorders becomes essential, as their associations are not always straightforward.

Aims & Objectives
In this study, we aimed to investigate factors associating with subsequent mood symptoms using data collected upon admission among patients with bipolar spectrum disorders including major depressive disorder, persistent depressive disorder, bipolar II disorder and bipolar I disorder. We hypothesized that baseline symptom profiles and demographic data may associate with the future course of manic/depressive symptoms respectively.

Methods
Data were collected from patients who were admitted to the psychiatry ward of Hokkaido University Hospital from 2010 to 2022 and were diagnosed with major depressive disorder, persistent depressive disorder, bipolar II disorder, bipolar I disorder, and organic mood disorders excluding any type of dementia (n=259). All the patients were evaluated by Young Mania Rating Scale (YMRS) and Hamilton Depression Rating Scale (HAM-D) at admission and 4 weeks after admission. Other psychometric scales such as Mood Disorder Questionnaire (MDQ), diagnostic criteria for bipolar spectrum disorder proposed by Ghaemi et al., and Patient Health Questionnaire-9 (PHQ-9) were also surveyed on admission. Several linear regression models were applied to the baseline data to predict the score change. This study protocol was approved by the Hokkaido University Institutional Review Board.

Results
Linear regression models revealed that subsequent HAM-D total score was associated with baseline demographic data and some of the core item of HAM-D. We found similar result with the association between baseline of each YMRS items and YMRS total score 4 weeks after. The models for YMRS and HAM-D had scarcely shared common risk variables for emotional dysregulation. We consequently analyzed association between each YMRS items and HAM-D items by using dimensionality reduction approach, which demonstrated significant correlations between these psychometric items. In addition, these associations may be well influenced by the sex differences.

Discussion & Conclusion
From the analysis, subsequent manic symptoms using YMRS may be well described by the baseline variables related with mania. On the other hand, deducting the factors associated with subsequent depressive symptoms using HAM-D was relatively challenging, suggesting that depressive and manic symptoms could not be opposite poles.