OBJECTIVE: Alterations in neuroelectrical activities coincide with major depressive disorder (MDD). This study examines the pattern of cerebral activity and cardiac autonomic parameters of euthymic women with recurrent MDD. METHODS: Resting electroencephalograms and electrocardiograms were recorded from 20 women with MDD receiving escitalopram and 40 matched and healthy women. We computed frontal alpha asymmetry to evaluate the interhemispheric balance. Parameters of heart rate variability were extracted to assess cardiac autonomic control. Sample entropy was used to assess the complexity of neurocardiac dynamics. The relationship between cardiovagal activity and alpha electroencephalogram was examined with a coherence analysis. RESULTS: Multivariable analysis of variance revealed a differential pattern of psychophysiologic variables between MDD patients and controls (p = .03). MDD was associated with a tendency toward lower left frontal activity (-0.06 [standard deviation = 0.14] versus 0.04 [0.17] lnμV(2), p = .04). Discriminant analysis demonstrated more right frontal activation, a lower high-frequency heart rate power spectrum, and a higher ratio of the low- to high-frequency heart rate power spectrum in patients with MDD compared with controls. Residual depressive symptoms (r = -0.09 to 0.11, p = .63-.99) and escitalopram dosage (r = -0.09 to 0.28, p = .22-.84) were not correlated with autonomic measures. Coherence between normalized high-frequency component of the heart rate power spectrum and alpha power was not significant (F3, p = .27; F4, p = .16). CONCLUSIONS: Euthymic women with recurrent MDD have a distinctive psychophysiologic profile. This profile may reflect altered frontal activation and a reduced cardiovagal tone in depression.
OBJECTIVE: Alterations in neuroelectrical activities coincide with major depressive disorder (MDD). This study examines the pattern of cerebral activity and cardiac autonomic parameters of euthymic women with recurrent MDD. METHODS: Resting electroencephalograms and electrocardiograms were recorded from 20 women with MDD receiving escitalopram and 40 matched and healthy women. We computed frontal alpha asymmetry to evaluate the interhemispheric balance. Parameters of heart rate variability were extracted to assess cardiac autonomic control. Sample entropy was used to assess the complexity of neurocardiac dynamics. The relationship between cardiovagal activity and alpha electroencephalogram was examined with a coherence analysis. RESULTS: Multivariable analysis of variance revealed a differential pattern of psychophysiologic variables between MDDpatients and controls (p = .03). MDD was associated with a tendency toward lower left frontal activity (-0.06 [standard deviation = 0.14] versus 0.04 [0.17] lnμV(2), p = .04). Discriminant analysis demonstrated more right frontal activation, a lower high-frequency heart rate power spectrum, and a higher ratio of the low- to high-frequency heart rate power spectrum in patients with MDD compared with controls. Residual depressive symptoms (r = -0.09 to 0.11, p = .63-.99) and escitalopram dosage (r = -0.09 to 0.28, p = .22-.84) were not correlated with autonomic measures. Coherence between normalized high-frequency component of the heart rate power spectrum and alpha power was not significant (F3, p = .27; F4, p = .16). CONCLUSIONS: Euthymic women with recurrent MDD have a distinctive psychophysiologic profile. This profile may reflect altered frontal activation and a reduced cardiovagal tone in depression.