Changes in Physiological Modulation of Arousal Following CBT Intervention in Women with Alcohol Use Problems

Introduction:The cardiovascular system (CVS) actively participates in emotional and behavioral regulation including alcohol use behaviors. The CVS through the baroreflex dampens stress reactions, strong emotions, and possibly, craving. As a protective mechanism, the baroreflex controls blood pressure (BP) and, more importantly, body-brain communication. Heart rate variability (HRV) actively participates in this mechanism as a modulator of inhibitory processes in the brain. This mechanism is relevant to alcohol problem prevention and intervention. Alcohol impairs baroreflex gain and HRV, thus creating risk for alcohol misuse aimed at emotional regulation. The aim of the study was to examine CVS changes that occurred over 3 months of cognitive behavioral therapy (CBT) for women with alcohol use disorders. We evaluated the potential utility of cardiovascular parameters in assessing intervention efficacy.

Method: Participants were 34 women between the ages of 25 and 61 years (M=48.29, SD=10.32) who took part in a study of 12 weekly sessions of outpatient CBT for alcohol use disorders. CVS parameters and amount and frequency of alcohol consumption, were collected pre- and post-treatment. CVS data were recorded in two five-minute tasks: baseline task and a slow paced breathing (6 times/min) task. Time and frequency domain analyses of the heart rate (HR), blood pressure (BP), stroke volume (SV), vascular tone (VT), total peripheral resistance (TPR), and variability of these functions, including the baroreflex gain, were completed for each participant. Repeated measures MANOVA was used to examine change in CVS functions and alcohol use.

Results:The amount and frequency of alcohol intake in CBT participants was significantly decreased, as was mean HR (F=14.45, p=.0003), SV (F=4.88, p=.0307), VT (F=8.04, p=.0061), and very low frequency variability of SV (F=24.54, p<.0001) and VT (F=8.43, p=.0050). Baroreflex gain (F=4.67, p=.0345) and total HRV (F=8.5, p=.0069) significantly increased. HRV parameters that reflect vagus activity (HF HRV and RMSSD) did not change significantly. Decreases in drinking frequency correlated (r=-0.39, p=0.022) with increases in baroreflex gain.

Conclusion: Women who completed 3 months of CBT not only reduced their alcohol consumption, but also experienced significant CVS improvement. CBT may help restore sympathetic–vagal balance through diminished sympathetic activity (mean HR, SV, and VT reduction). Increased baroreflex gain and HRV strengthen patients’ ability to cope with negative affect and craving. Assessment of CVS parameters may serve as an additional tool to objectively assess alcohol intervention outcome, and have implications for the prevention of alcohol misuse.

Supported by: R01AA017163, R21AA020367, HHSN275201000003C.