| dc.description.abstract | Objective: This study focused on the effects of manic episodes on total brain and grey matter
volumes and general intelligence (IQ) in patients with a bipolar type I disorder (BPI). Volumetric
reductions of the total brain and grey matter have been observed in patients with BPI. In
addition, cognitive impairments are found to persevere in a euthymic state, which implicates
enduring poorer cognitive functioning after mood episodes. The severity of the illness, including
the number of mood episodes, has been related to these structural and cognitive impairments.
The precise relation of manic episodes on neuroanatomical changes and change in cognitive
functioning remains inconclusive, and will therefore be examined in this study. Methods: A total
of 64 euthymic patients diagnosed with BPI and 45 healthy control subjects participated in this
study. The BPI diagnosis and the euthymic state were verified using the Structured Clinical
Interview for DSM-IV disorders (SCID-I). Participants completed a number of questionnaires, a
structured interview, and five neuropsychological tasks. Of the participants, 62 patients and 16
control subjects participated in the magnetic resonance imaging (MRI) follow-up appointment,
which included a number of structural scans. Results: Patients had smaller total brain volumes
than control participants, but similar grey matter volumes. No relation between grey matter
volumes and general IQ was found. However, patients had a lower general IQ compared to
controls participants, whilst the groups did not differ in premorbid IQ. Furthermore, patients
who experienced multiple manic episodes showed a larger decrease in general IQ compared to
patients who experienced a single manic episode. Conclusions: This study indicates that manic
episodes have a specific negative effect on total brain volumes and general IQ. Since the level of
general IQ has been related to the functional outcome of the disorder, a higher number of manic
episodes can have a negative effect on the psychosocial level of functioning and the quality of life
of patients. Future research should therefore continue to investigate the effects of manic
episodes on a structural as well as a functional level. | |
