Comparison of parietal cortex volume and functions in major depression and bipolar disorder using a cloud based brain magnetic resonance image segmentation-parcellation system and a neuropsychological test

Objective: In this study, it was aimed to evaluate the PL volume and functions in a holistic manner by comparing the Parietal Lobe (PL) volumes of Bipolar Disorder (BD) and Major Depressive Disorder patients among themselves and with healthy controls. Material and Method: This study was conducted in 3 groups and 63 participants, including patients in remission who were diagnosed with BD and MDD according to DSM-V, and healthy controls. Sociodemographic Information Form was filled out by the participants and a Cancellation Test (CT) was performed. Beck Depression Inventory (BDI) was filled by patient groups. Hamilton Depression Rating Scale (HDRS) was applied by the patient group with BD and MDD and the Young Mania Rating Scale (YMRS) was applied by the patient group with BD. Based on the scores obtained from the scales and clinical evaluation, the patients were diagnosed with remission. PL volumes of the participants were measured using MRIcloud System. By comparing the results of the CT with the MRI findings, it was evaluated whether PL functions were impaired in diseases. Results: When three groups were compared in terms of both right and left PL volumes, it was observed that both BD and MDD patients had lower PL volumes than the control group, and there was no significant difference between patient groups in terms of PL volumes. PL volume was lower in those who were hospitalized, women, had an illness longer than 5 years, and had a manic or depressive episode at least once. Likewise, in these cases, low performance was detected in CT. Discussion: Our study showed that there is lower PL volume and worse PL functions in patients with BD and MDD, even in the remission period, compared to healthy people. The results of our research emphasize the importance of PL in understanding the pathophysiology of BD and MDD and developing neuroanatomical and functional markers for these diseases. Keywords: parietal lobe volume, bipolar disorder, deppression, neuropsychological test