期刊名称：Proceedings of the National Academy of Sciences
印刷版ISSN：0027-8424
电子版ISSN：1091-6490
出版年度：2022
卷号：119
期号：28
DOI：10.1073/pnas.2202983119
语种：English
出版社：The National Academy of Sciences of the United States of America
摘要：Significance
Extreme mood variability causes significant difficulties in bipolar disorder (BD) and borderline personality disorder (BPD). It is not clear how to conceptualize or measure mood variability, which makes it challenging to assess how treatments for these conditions work. We developed and deployed a computational model, which estimates whether mood variation is persistent versus transient, in patients with BD and BPD, and in a randomized study of lithium. We found that the BD group displayed persistent changes in mood, whereas the BPD group experienced transient changes. Lithium increased persistent changes of positive mood. This work demonstrates that specific types of mood variability are associated with BD and BPD, and suggests a way of understanding how lithium prevents extreme mood states.
The affective variability of bipolar disorder (BD) is thought to qualitatively differ from that of borderline personality disorder (BPD), with changes in affect persisting longer in BD. However, quantitative studies have not been able to confirm this distinction. It has therefore not been possible to accurately quantify how treatments like lithium influence affective variability in BD. We assessed the affective variability associated with BD and BPD as well as the effect of lithium using a computational model that defines two subtypes of variability: affective changes that persist (volatility) and changes that do not (noise). We hypothesized that affective volatility would be raised in the BD group, noise would be raised in the BPD group, and that lithium would impact affective volatility. Daily affect ratings were prospectively collected for up to 3 y from patients with BD or BPD and nonclinical controls. In a separate experimental medicine study, patients with BD were randomized to receive lithium or placebo, with affect ratings collected from week −2 to +4. We found a diagnostically specific pattern of affective variability. Affective volatility was raised in patients with BD, whereas affective noise was raised in patients with BPD. Rather than suppressing affective variability, lithium increased the volatility of positive affect in both studies. These results provide a quantitative measure of the affective variability associated with BD and BPD. They suggest a mechanism of action for lithium, whereby periods of persistently low or high affect are avoided by increasing the volatility of affective responses.
