Frontopolar cortex activation associated with pessimistic future-thinking in adults with major depressive disorder.

BACKGROUND:Pessimistic thinking about the future is one of the cardinal symptoms of major depressive disorder (MDD) and is an important domain of cognitive functioning associated with hopelessness. Neuroimaging studies have shown that the frontopolar cortex (Brodmann area [BA] 10) is involved in thinking about the future and demonstrated that patients with MDD have dysfunctions in BA10. However, the relationship between pessimistic thinking about the future and brain activity is unclear. Hence, we aimed to compare brain activity during future-thinking between patients with MDD and healthy individuals. METHODS:We assessed 23 patients with current MDD and 23 healthy individuals. Participants were instructed to imagine the future or to recall the past using the future-thinking paradigm with four distinct temporal conditions (distant future, near future, distant past, and near past) during functional MRI. Resting-state functional MRI was also performed to explore the functional connectivity of BA10. RESULTS:Compared with healthy individuals, patients with MDD had greater negative thinking about the distant future and exhibited increased activation in the medial BA10 when imagining the distant future, following small-volume correction focusing on the frontopolar a priori region of interest (family-wise error correction p < 0.05). Increased positive functional correlation between the right BA10 seed region and the posterior cingulate cortex was also observed. CONCLUSION:Patients with MDD who show greater pessimistic thinking about the distant future demonstrate increased activation in the frontopolar cortex. These findings are consistent with the hypothesis that frontopolar cortical dysfunction plays a key role in the hopelessness that manifests in patients with MDD.