title: Hippocampal volume and verbal memory performance in late-stage bipolar disorder.
abstract: Studies about changes in hippocampal volumes in subjects with bipolar disorder (BD) have been contradictory. Since the number of manic episodes and hospitalization has been associated with brain changes and poor cognitive outcomes among BD patients, we have hypothesized that these variables could clarify this issue. We stratified subjects with BD in early (BD-Early), intermediate (BD-intermediate) and late (BD-Late) stages as a function of number of manic episodes and prior hospitalization. Then, we compared their hippocampal volumes and California Verbal Learning Test-II (CVLT-II) scores with healthy controls (HC) using the general linear model. A total of 173 subjects were included in the study (112 HC, 15 BD-Early, 30 BD-Intermediate, and 16 BD-Late). We found a significant group effect on hippocampus volume (F(3,167) = 3.227, p = 0.024). Post-hoc analysis showed that BD-Late subjects had smaller hippocampus than HC (p = 0.017). BD-Early and BD-Intermediate subjects showed no significant difference in hippocampus volume compared to HC and BD-Late subjects. The CVLT trial 1 to 5 scores were significantly different across the groups (F(3,167) = 6.371, p < 0.001). Post-hoc analysis showed that BD-Intermediate (p = 0.006) and BD-Late (p = 0.017) subjects had worse memory performance during immediate recall than HC, while the performance difference between BD-Early subjects and HC was not significant (p = 0.208). These findings add to the notion that BD is a neuroprogressive disorder with brain changes and cognitive impairment according to prior morbidity (number of manic episodes and hospitalization). Also, they suggest that hippocampus is a brain marker and a potential therapeutic target for patients at late stage.
authors.affiliation: UT Center of Excellence on Mood Disorder, Department of Psychiatry and Behavioral Sciences, The University of Texas Science Center at Houston, Houston, TX, USA.
authors.forename: Bo
authors.initials: B
authors.lastname: Cao
authors.affiliation: UT Center of Excellence on Mood Disorder, Department of Psychiatry and Behavioral Sciences, The University of Texas Science Center at Houston, Houston, TX, USA.|Bipolar Disorder Program and Laboratory of Molecular Psychiatry, Federal University of Rio Grande do Sul, Porto Alegre, RS, Brazil.
authors.forename: Ives Cavalcante
authors.initials: IC
authors.lastname: Passos
authors.affiliation: UT Center of Excellence on Mood Disorder, Department of Psychiatry and Behavioral Sciences, The University of Texas Science Center at Houston, Houston, TX, USA.
authors.forename: Benson
authors.initials: B
authors.lastname: Mwangi
authors.affiliation: UT Center of Excellence on Mood Disorder, Department of Psychiatry and Behavioral Sciences, The University of Texas Science Center at Houston, Houston, TX, USA.
authors.forename: Isabelle E
authors.initials: IE
authors.lastname: Bauer
authors.affiliation: UT Center of Excellence on Mood Disorder, Department of Psychiatry and Behavioral Sciences, The University of Texas Science Center at Houston, Houston, TX, USA.
authors.forename: Giovana B
authors.initials: GB
authors.lastname: Zunta-Soares
authors.affiliation: UT Center of Excellence on Mood Disorder, Department of Psychiatry and Behavioral Sciences, The University of Texas Science Center at Houston, Houston, TX, USA.|Bipolar Disorder Program and Laboratory of Molecular Psychiatry, Federal University of Rio Grande do Sul, Porto Alegre, RS, Brazil.
authors.forename: Flávio
authors.initials: F
authors.lastname: Kapczinski
authors.affiliation: UT Center of Excellence on Mood Disorder, Department of Psychiatry and Behavioral Sciences, The University of Texas Science Center at Houston, Houston, TX, USA.
authors.forename: Jair C
authors.initials: JC
authors.lastname: Soares
mesh_terms: D000328:Adult; D000704:Analysis of Variance; D001714:Bipolar Disorder / Q000150:complications* / Q000473:pathology*; D003430:Cross-Sectional Studies; D018450:Disease Progression; D005260:Female; D006624:Hippocampus / Q000473:pathology*; D006801:Humans; D007091:Image Processing, Computer-Assisted; D008279:Magnetic Resonance Imaging; D008297:Male; D008569:Memory Disorders / Q000209:etiology*; D008875:Middle Aged; D009483:Neuropsychological Tests; D011569:Psychiatric Status Rating Scales; D014706:Verbal Learning / Q000502:physiology*; D055815:Young Adult
keywords: Bipolar disorder; Hippocampus; Neuroprogression; Staging; Verbal memory