Background: Frontostriatal disconnectivity plays a crucial role in the pathophysiology of major depressive disorder. However, whether the baseline functional connectivity of the frontostriatal network could predict the treatment outcome of low-dose ketamine infusion remains unknown.
Methods: In total, 48 patients with treatment-resistant depression were randomly divided into 3 treatment groups (a single-dose 40-minute i.v. infusion) as follows: 0.5 mg/kg ketamine, 0.2 mg/kg ketamine, and saline placebo infusion. Patients were subsequently followed-up for 2 weeks. Resting-state functional magnetic resonance imaging was performed for each patient before infusion administration. In addition, the baseline frontostriatal functional connectivity of patients with treatment-resistant depression was also compared with that of healthy controls.
Results: Compared with the healthy controls, patients with treatment-resistant depression had a decreased functional connectivity in the frontostriatal circuits, especially between the right superior frontal cortex and executive region of the striatum and between the right paracingulate cortex and rostral-motor region of the striatum. The baseline hypoconnectivity of the bilateral superior frontal cortex to the executive region of the striatum was associated with a greater reduction of depression symptoms after a single 0.2-mg/kg ketamine infusion.
Conclusion: Reduced connectivity of the superior frontal cortex to the striatum predicted the response to ketamine infusion among patients with treatment-resistant depression.
Keywords: frontostriatal network; low-dose ketamine infusion; treatment response; treatment-resistant depression.
© The Author(s) 2020. Published by Oxford University Press on behalf of CINP.