Respiratory sinus arrhythmia was significantly lower in patients with bipolar depression compared to healthy controls, serving as the primary variable distinguishing the groups.
Cross-Sectional (n=95)
Do autonomic measures (respiratory sinus arrhythmia, low-frequency heart rate variability, and systolic blood pressure) differentiate between bipolar depression, major depressive disorder, and healthy controls?
Assessment of respiratory sinus arrhythmia and systolic blood pressure may serve as useful physiological markers to aid in the differential diagnosis of bipolar depression versus major depressive disorder.
Effect estimate: Mean difference -1.10 (95% CI -1.73 to -0.47)
Absolute Event Rate: 4.27% vs 5.36%
p-value: p=<0.0005
OBJECTIVE: The present study aimed at exploring the potential utility of autonomic regulation as a useful marker in the diagnostic differentiation between unipolar and bipolar depression. METHOD: Respiratory sinus arrhythmia (RSA), low-frequency (LF) of heart rate variability, and systolic blood pressure (SBP) were assessed in patients with bipolar depression (31) and major depressive disorder (MDD=32), and in healthy controls (HCs=32). Since bipolar depressed subjects were maintained on specific medications to manage manic/hypomanic symptoms, we explored whether mood stabilizers (atypical antipsychotics and anticonvulsants or their combinations) could independently affect the physiological parameters. RESULTS: When the autonomic measures were analyzed by a multivariate analysis of variance (MANCOVA), after controlling for BMI, the combination of variables (RSA, LF, SBP) discriminated patients with bipolar depression and MDD from HC (F(()6(, 178))=3.036, p=0.007, Λ=0.823, partial η(2)=0.093). In any case, we cannot exclude that mood stabilizers might have affected SBP values in the bipolar group. To deconstruct this multivariate effect, pairwise ANOVAs and discriminant analyses contrasted groups and documented that RSA was the primary variable distinguishing the groups. Discriminant function analyses showed that RSA had a significant discriminating weight between bipolar depressed patients and HC subjects (p<0.0005). By contrast, RSA showed a trend towards the statistical significance in discriminating between bipolar depression and MDD patients (p=0.06). CONCLUSIONS: The assessment of RSA and SBP in outpatient settings might be helpful in the differential diagnosis of affective disorders.
Guccione et al. (Tue,) conducted a cross-sectional in Bipolar depression and Major Depressive Disorder (n=95). Autonomic measures assessment vs. Healthy controls was evaluated on Respiratory sinus arrhythmia (RSA) (Mean difference -1.10, 95% CI -1.73 to -0.47, p=<0.0005). Respiratory sinus arrhythmia was significantly lower in patients with bipolar depression compared to healthy controls, serving as the primary variable distinguishing the groups.