Estudi de variables fenotípiques i genotípiques en el trastorn bipolar i la seva relació amb la resposta al tractament amb liti

Abstract

Introduction Bipolar disorder is a serious mental disorder characterized by mood changes with the presence of manic, depressive or mixed phases and significant functional impairment. The biological basis is multifactorial involving genetic and environmental factors. Treatment has evolved over time, but for more than 70 years lithium has remained the most effective drug in relapse prevention. The response to lithium treatment is a concept that has varied throughout the literature and even today does not have a unanimous consensus. Up to one-third of patients treated with lithium have an excellent response, another third have no response, and the rest have a partial response. The Alda scale is a validated tool to assess this response. Several clinical and genetic variables related to response to lithium treatment (the mania-depression sequence, the absence of rapid cycling or the absence of psychotic symptoms) have been described. The predominant polarity is a clinical variable present in 50% of those affected and has clinical implications in the age of onset of the disease, the polarity of the debut episode or the response to treatment. This is the first work in which the relationship between predominant polarity and the response to lithium treatment assessed with the Alda scale is studied. Methodology This is a multicentre observational study in which clinical data have been collected from 1058 people diagnosed with bipolar disorder treated with lithium and their response measured with the Alda scale. Degrees of association between clinical variables and response to lithium treatment were assessed using the odds ratio with a 95% confidence interval using univariate logistic regression models. Results Manic polarity predominance is associated with a better response to lithium treatment compared to depressive predominant polarity (OR: 1.95; 95% CI: 1.39 - 2.74; p<0.001) and no predominant polarity (OR: 1.39; CI 95%: 1.03 - 1.88; p=0.032). Patients diagnosed with bipolar II disorder have a better response to lithium treatment than those diagnosed with bipolar I disorder (OR: 1.78; 95% CI: 1.20 - 2.63; p=0.004 ). Patients with a first maniform episode have a better response to lithium treatment compared to those who debut with a depressive episode (OR: 1.51; CI 95%: 1.12 - 2.03; p=0.007). Patients without a history of autolytic attempts have a better response to lithium treatment than those with one (OR: 0.41; CI 95%: 0.29 - 0.57; p<0.001). No significant differences were found in the variables of gender, age of onset of the disorder, family history of bipolar disorder or family history of lithium treatment. Conclusion Maniac predominant polarity is a factor associated with good response to lithium treatment in bipolar disorder along with the diagnosis of bipolar II disorder, presenting with a first manic-type episode and not presenting autolytic attempts in evolution. The polarity of the debut episode and the diagnostic subtype are not independent variables of predominant polarity.

Date of Award	2 Jul 2024
Original language	Catalan
Supervisor	Francesc Colom Victoriano (Director) & Victor Perez Sola (Director)