Regional brain volume in depression and anxiety disorders.

CONTEXT: Major depressive disorder (MDD), panic disorder, and social anxiety disorder are among the most prevalent and frequently co-occurring psychiatric disorders in adults and may have, at least in part, a common etiology.
OBJECTIVE: To identify the unique and shared neuroanatomical profile of depression and anxiety, controlling for illness severity, medication use, sex, age of onset, and recurrence.
DESIGN: Cross-sectional study.
SETTING: Netherlands Study of Depression and Anxiety. PARTICIPANTS: Outpatients with MDD (n = 68), comorbid MDD and anxiety (n = 88), panic disorder, and/or social anxiety disorder without comorbid MDD (n = 68) and healthy controls (n = 65). MAIN OUTCOME MEASURES: Volumetric magnetic resonance imaging was conducted for voxel-based morphometry analyses. We tested voxelwise for the effects of diagnosis, age at onset, and recurrence on gray matter density. Post hoc, we studied the effects of use of medication, illness severity, and sex.
RESULTS: We demonstrated lower gray matter volumes of the rostral anterior cingulate gyrus extending into the dorsal anterior cingulate gyrus in MDD, comorbid MDD and anxiety, and anxiety disorders without comorbid MDD, independent of illness severity, sex, and medication use. Furthermore, we demonstrated reduced right lateral inferior frontal volumes in MDD and reduced left middle/superior temporal volume in anxiety disorders without comorbid MDD. Also, patients with onset of depression before 18 years of age showed lower volumes of the subgenual prefrontal cortex.
CONCLUSIONS: Our findings indicate that reduced volume of the rostral-dorsal anterior cingulate gyrus is a generic effect in depression and anxiety disorders, independent of illness severity, medication use, and sex. This generic effect supports the notion of a shared etiology and may reflect a common symptom dimension related to altered emotion processing. Specific involvement of the inferior frontal cortex in MDD and lateral temporal cortex in anxiety disorders without comorbid MDD, on the other hand, may reflect disorder-specific symptom clusters. Early onset of depression is associated with a distinct neuroanatomical profile that may represent a vulnerability marker of depressive disorder.