van Tol MJ, van der Wee NJA, Demenescu LR, Nielen MMA, Aleman A, Renken R, van Buchem MA, Zitman FG, Veltman DJ. Functional MRI correlates of visuospatial planning in out-patient depression and anxiety.
Objective: Major depressive disorder (MDD) has been associated with executive dysfunction and related abnormal prefrontal activity, whereas the status of executive function (EF) in frequently co-occurring anxiety disorders and in comorbid depression–anxiety is unclear. We aimed to study functional MRI correlates of (visuospatial) planning in MDD and anxiety disorders and to test for the effects of their comorbidity.
Method: Functional MRI was employed during performance of a parametric Tower of London task in out-patients with MDD (n = 65), MDD with comorbid anxiety (n = 82) or anxiety disorders without MDD (n = 64), and controls (n = 63).
Results: Moderately/severely depressed patients with MDD showed increased left dorsolateral prefrontal activity as a function of task load, together with subtle slowing during task execution. In mildly depressed and remitted MDD patients, in anxiety patients, and in patients with comorbid depression–anxiety, task performance was normal and no activation differences were observed. Medication use and regional brain volume were not associated with altered visuospatial planning.
Conclusion: Prefrontal hyperactivation during high planning demands is not a trait characteristic, but a state characteristic of MDD without comorbid anxiety, occurring independent of SSRI use. Disturbances in planning or the related activation are probably not a feature of anxiety disorders with or without comorbid MDD, supporting the current distinction between anxiety disorders and depression.