DOI: 10.1111/bdi.70166 ISSN: 1398-5647
Cortical Thickness in Middle and Older Aged Adults With Bipolar Disorder Across Six International Sites
Rebecca Marks, Anjali Sankar, Lejla Colic, Jair Soares, Joaquim Radua, Eduard Vieta, Benson Mwangi, Mon‐Ju Wu, Enric Vilajosana, Edith Pomarol‐Clotet, Erick Canales‐Rodríguez, Raymond Salvador, Brian Pittman, Annemieke Dols, Martha Sajatovic, Lisa T. Eyler, Hilary P. Blumberg ABSTRACT
Background
Older adults with bipolar disorder (
BD
) are at high risk for severe mood symptoms, cognitive difficulties, and early mortality; however, underlying brain alterations have received little study. Gray matter decreases in ventral prefrontal cortex (
VPFC
) seen in younger persons with
BD
, and additionally in dorsal
PFC
(
DPFC
), are implicated. Here, cortical thickness was examined in an international sample.
Methods
Cortical thickness in 34 regions was measured from structural magnetic resonance imaging data using enhancing
neuroImaging
genetics through meta‐analysis pipelines for individuals with
BD
(
n
= 308) and non‐psychiatric comparison participants (
n
= 287), ages 40–70y, from six Global Aging and Geriatric Experiments in
BD
(
GAGE
‐
BD
) consortium sites. Group differences were assessed for
VPFC
,
DPFC
and remaining cortical regions, covarying for scanner, age and sex. Results were considered significant corrected for false discovery fate (
FDR
) at
p
FDR
<
0.05. Relationships with demographic and clinical factors were explored.
Results
Cortical thickness was significantly lower among
BD
in
VPFC
and
DPFC
, and additional distributed regions (
p
FDR
<
0.05) and negatively associated with age (
p
< 0.05); group and age did not interact significantly. Relationships with
BD
subtype and medications were observed; lithium was associated with higher frontal pole and anterior cingulate thickness (
p
FDR
<
0.05).
Conclusions
In this international middle and older aged adult
BD
sample, lower
VPFC
cortical thickness was observed, suggesting these deficits persist from younger age.
DPFC
and additional regions of reduced cortical thickness could contribute to the older adult
BD
phenotype. Cortical thinning was more pronounced among older individuals regardless of diagnosis. Lithium may lessen cortical thinning.