Cardiac autonomic tone, plasma BDNF levels and paroxetine response in newly diagnosed patients of generalised anxiety disorder

Abstract

Objective: The study examined the effect on cardiac autonomic tone via heart rate variability (HRV), brain derived neurotrophic factor (BDNF) in newly diagnosed generalised anxiety disorder (GAD) cases with paroxetine-controlled release (PX) CR intervention.

Methods: Fifty GAD cases using DSM-5 criteria, matched with healthy controls (HC) were assessed with clinical measures (Hamilton Anxiety Scale (HAM-A), Clinical Global Impression- Severity Scale (CGI-Severity), General Health Questionnaire -12 (GHQ-12), HRV, plasma BDNF levels initially and 6 weeks postintervention with paroxetine CR.

Results: HRV parameters were significantly lower in GAD vs HC at baseline for standard deviation of normal to normal intervals (SDNN) and proportion of differences in consecutive NN intervals that are longer than 50 ms (pNN50). Significantly higher plasma BDNF levels were noted between HC versus GAD at baseline. Postintervention HAM-A, CGI scores, GHQ-12 item scores showed significant reduction. Significant differences also noted in square root of mean squared difference of successive NN intervals (RMSSD), (SDNN), pNN50 and in plasma BDNF levels after intervention within GAD group. Significant negative correlation observed between HAM-A scores and SDNN parameter after taking PX CR in GAD.

Conclusion: GAD showed cardiac autonomic dysfunction, lowered plasma BDNF levels and their improvement with paroxetine CR.

Key message

• GAD is associated with significantly lower HRV, suggestive of cardiac autonomic dysfunction and lowered plasma BDNF levels, an indicator of stress.

• Therapeutic intervention with Paroxetine in GAD patients showed clinically significant improvement reflecting restoration of the cardiac autonomic tone and BDNF levels, thus implying their role as potential biomarkers.

Keywords:

• Generalised anxiety disorder
• pNN50
• SDNN
• cardiac autonomic tone
• BDNF
• paroxetine

Disclosure statement

All authors declare that they are in agreement with the content of the manuscript and they don’t have any conflict of interest. The infrastructure for the study was provided internally by the University College of Medical Sciences, Delhi.

Author contributions

All authors have materially participated in this research and manuscript preparation. All authors have approved the final version of this manuscript to be submitted. RD, NS, SS, AY conceptualised and designed the study, RD and SS recruited the patients. NS, SS, AY and RA helped RD for the acquisition and analysis of the data. All authors contributed in the drafting of the manuscript, revising it for important intellectual content, gave final approval of the version to be published and agreed to be accountable for all aspects of the work.