Carmilla M.M. Licht

Association between major depressive disorder and heart rate variability in the Netherlands Study of Depression and Anxiety (NESDA).

CONTEXT It has been hypothesized that depression is associated with lower heart rate variability and decreased cardiac vagal control. This may play an important role in the risk of cardiovascular disease among depressed individuals. OBJECTIVE To determine whether heart rate variability was lower in depressed individuals than in healthy controls in a large adult sample. DESIGN Cross-sectional analyses from a large depression cohort study. SETTING The Netherlands Study of Depression and Anxiety. PARTICIPANTS Two thousand three hundred seventy-three individuals (mean age, 41.8 years; 66.8% female) who participated in the Netherlands Study of Depression and Anxiety. Included were 524 controls, 774 individuals with a diagnosis of major depressive disorder (MDD) earlier in life (remitted MDD), and 1075 individuals with current MDD based on the Composite International Diagnostic Interview. This sample was sufficiently powered to examine the confounding effects of lifestyle, comorbid anxiety, and antidepressants. MAIN OUTCOME MEASURES The standard deviation of normal-to-normal beats (SDNN) and cardiac vagal control, as indexed by respiratory sinus arrhythmia (RSA), were measured during 1(1/2) hours of ambulatory recording of electrocardiograms and thorax impedance. Multivariate analyses were conducted to compare SDNN and RSA across depression groups after adjustment for demographics, health, lifestyle, comorbid anxiety, and psychoactive medication. RESULTS Individuals with remitted and current MDD had a lower mean SDNN and RSA compared with controls (SDNN, 3.1-5.7 milliseconds shorter, P < or = .02; RSA, 5.1-7.1 milliseconds shorter, P < .001; effect size, 0.125-0.269). Comorbid anxiety and lifestyle did not reduce these associations. However, accounting for psychoactive medication removed the association with SDNN and strongly attenuated the association with RSA. Depressed individuals who were using selective serotonin reuptake inhibitors, tricyclic antidepressants, or other antidepressants had significantly shorter SDNNs and RSAs (effect size, 0.207-0.862) compared with controls and depressed individuals not taking medication. CONCLUSIONS This study shows that depression is associated with significantly lowered heart rate variability. However, this association appears to be mainly driven by the effect of antidepressants.

Depression is associated with decreased blood pressure, but antidepressant use increases the risk for hypertension

The present study compared blood pressure levels between subjects with clinical anxiety and depressive disorders with healthy controls. Cross-sectional data were obtained in a large cohort study, the Netherlands Study of Depression and Anxiety (N=2981). Participants were classified as controls (N=590) or currently or remittedly depressed or anxious subjects (N=2028), of which 1384 were not and 644 were using antidepressants. Regression analyses calculated the contributions of anxiety and depressive disorders and antidepressant use to diastolic and systolic blood pressures, after controlling for multiple covariates. Heart rate and heart rate variability measures were subsequently added to test whether effects of anxiety/depression or medication were mediated by vagal control over the heart. Higher mean diastolic blood pressure was found among the current anxious subjects (β=0.932; P=0.03), although anxiety was not significantly related to hypertension risk. Remitted and current depressed subjects had a lower mean systolic blood pressure (β=−1.74, P=0.04 and β=−2.35, P=0.004, respectively) and were significantly less likely to have isolated systolic hypertension than controls. Users of tricyclic antidepressants had higher mean systolic and diastolic blood pressures and were more likely to have hypertension stage 1 (odds ratio: 1.90; 95% CI: 0.94 to 3.84; P=0.07) and stage 2 (odds ratio: 3.19; 95% CI: 1.35 to 7.59; P=0.008). Users of noradrenergic and serotonergic working antidepressants were more likely to have hypertension stage 1. This study shows that depressive disorder is associated with low systolic blood pressure and less hypertension, whereas the use of certain antidepressants is associated with both high diastolic and systolic blood pressures and hypertension.

Increased sympathetic and decreased parasympathetic activity rather than changes in hypothalamic-pituitary-adrenal axis activity is associated with metabolic abnormalities.

CONTEXT Stress is suggested to lead to metabolic dysregulations as clustered in the metabolic syndrome, but the underlying biological mechanisms are not yet well understood. OBJECTIVE We examined the relationship between two main str systems, the autonomic nervous system and the hypothalamic-pituitary-adrenal (HPA) axis, with the metabolic syndrome and its components. DESIGN The design was baseline data (yr 2004-2007) of a prospective cohort: the Netherlands Study of Depression and Anxiety (NESDA). SETTING The study comprised general community, primary care, and specialized mental health care. PARTICIPANTS This study included 1883 participants aged 18-65 yr. MAIN OUTCOME MEASURES Autonomic nervous system measures included heart rate, respiratory sinus arrhythmia (RSA; high RSA reflecting high parasympathetic activity), and preejection period (PEP; high PEP reflecting low sympathetic activity). HPA axis measures included the cortisol awakening response, evening cortisol, and a 0.5 mg dexamethasone suppression test as measured in saliva. Metabolic syndrome was based on the updated Adult Treatment Panel III criteria and included high waist circumference, serum triglycerides, blood pressure, serum glucose, and low high-density lipoprotein cholesterol. RESULTS RSA and PEP were both independently negatively associated with the presence of the metabolic syndrome, the number of metabolic dysregulations as well as all individual components except high-density lipoprotein cholesterol (all P < 0.02). Heart rate was positively related to the metabolic syndrome, the number of metabolic dysregulations, and all individual components (all P < 0.001). HPA axis measures were not related to metabolic syndrome or its components. CONCLUSION Our findings suggest that increased sympathetic and decreased parasympathetic nervous system activity is associated with metabolic syndrome, whereas HPA axis activity is not.

Longitudinal Evidence for Unfavorable Effects of Antidepressants on Heart Rate Variability

BACKGROUND It was previously shown that antidepressants are associated with diminished vagal control over the heart. Longitudinal studies are needed to test the causality of this association further. METHODS Longitudinal data were obtained in the Netherlands Study of Depression and Anxiety. At baseline and at 2-year follow-up, heart rate and cardiac vagal control as indexed by respiratory sinus arrhythmia were measured in 2114 subjects (mean age = 42.0 years; 66.2% female), who either used antidepressants at one or two time points (n = 603) or did not use antidepressants at any time point (n = 1511). Linear mixed-model analyses were conducted to compare changes in respiratory sinus arrhythmia and heart rate over time across antidepressant-naive subjects, subjects who started using an antidepressant during follow-up, subjects who stopped using an antidepressant, and persistent antidepressant users. Analyses were adjusted for demographics, health, and lifestyle factors. RESULTS Compared with continuous nonusers, subjects who started the use of a tricyclic antidepressant or a serotonergic and noradrenergic antidepressant showed a significantly greater increase in heart rate and a decrease of respiratory sinus arrhythmia at 2 years. Subjects who started the use of selective serotonin reuptake inhibitors also showed a decrease in respiratory sinus arrhythmia, but their heart rate did not increase. Discontinuing antidepressants systematically caused opposite effects; levels returned in the direction of those observed among nonusers. CONCLUSIONS These 2-year longitudinal results indicate that all antidepressants cause a decrease in cardiac vagal control. After discontinuing antidepressants, autonomic function recovers, suggesting that the unfavorable effects are (partly) reversible.

Association between anxiety disorders and heart rate variability in The Netherlands Study of Depression and Anxiety (NESDA)

Objective: To determine whether patients with different types of anxiety disorder (panic disorder, social phobia, generalized anxiety disorder) have higher heart rate and lower heart rate variability compared with healthy controls in a sample that was sufficiently powered to examine the confounding effects of lifestyle and antidepressants. Methods: The standard deviation of the normal-to-normal intervals (SDNN), heart rate (HR), and respiratory sinus arrhythmia (RSA) were measured in 2059 subjects (mean age = 41.7 years, 66.8% female) participating in The Netherlands Study of Depression and Anxiety (NESDA). Based on the Diagnostic and Statistical Manual of Mental Disorders, 4th Edition (DSM-IV) and Composite International Diagnostic Interview (CIDI), NESDA participants were classified as healthy controls (n = 616), subjects with an anxiety diagnosis earlier in life (n = 420), and subjects with current anxiety diagnosis (n = 1059). Results: Current anxious subjects had a significantly lower SDNN and RSA compared with controls. RSA was also significantly lower in remitted anxious subjects compared with controls. These associations were similar across the three different types of anxiety disorders. Adjustment for lifestyle had little impact. However, additional adjustment for antidepressant use reduced all significant associations between anxiety and HRV to nonsignificant. Anxious subjects who used a tricyclic antidepressant, a selective serotonin reuptake inhibitor, or another antidepressant showed significantly lower mean SDNN and RSA compared with controls (effect sizes = 0.20–0.80 for SDNN and 0.42–0.79 for RSA). Nonmedicated anxious subjects did not differ from controls in mean SDNN and RSA. Conclusion: This study shows that anxiety disorders are associated with significantly lower HR variability, but the association seems to be driven by the effects of antidepressants. ANOVA = analysis of variance; ANS = autonomic nervous system; ATC = anatomical therapeutic chemical; BAI = Beck Anxiety Inventory; BMI = body mass index; CIDI = Composite International Diagnostic Interview; CVD = cardiovascular disease; dZ = changes in thorax impedance; ECG = electrocardiogram; GAD = generalized anxiety disorder; HR = heart rate; HRV = heart rate variability; IBI = inter-beat-interval; MDD = major depressive disorder; MET = multiple of ones resting metabolic rate times minutes of physical activity; NESDA = The Netherlands Study of Depression and Anxiety; PD = panic disorder; pv = peak-valley; PNS = parasympathetic nervous system; RR = respiratory rate; RSA = respiratory sinus arrhythmia; SDNN = standard deviation of the normal-to-normal interval; SNS = sympathetic nervous system; SP = social phobia; VU-AMS = Vrije Universiteit Ambulatory Monitoring System; SSRI = selective serotonin reuptake inhibitor; TCA = tricyclic antidepressant.

The impact of stress systems and lifestyle on dyslipidemia and obesity in anxiety and depression

BACKGROUND Dyslipidemia and obesity have been observed in persons with severe anxiety or depression, and in tricyclic antidepressant (TCA) users. This likely contributes to the higher risk of cardiovascular disease (CVD) in anxiety and depressive disorders. We aimed to elucidate whether biological stress systems or lifestyle factors underlie these associations. If so, they may be useful targets for CVD prevention and intervention. METHODS Within 2850 Netherlands Study of Depression and Anxiety (NESDA) participants, we evaluated the explaining impact of biological stress systems (i.e., the hypothalamic-pituitary-adrenal [HPA] axis, autonomic nervous system [ANS] and inflammation) and lifestyle factors (i.e., tobacco and alcohol use, and physical activity) on adverse associations of anxiety and depression severity and TCA use with high and low-density lipoprotein cholesterol, triglycerides, body mass index and waist circumference. Through linear regression analyses, percentual change (%Δ) in β was determined and considered significant when %Δ>10. RESULTS The inflammatory marker C-reactive protein had the most consistent impact (explaining 14-53% of the associations of anxiety and depression severity and TCA use with lipid and obesity levels), followed by tobacco use (explaining 34-43% of the associations with lipids). The ANS mediated all associations with TCA use (explaining 32-61%). The HPA axis measures did not explain any of the associations. CONCLUSIONS Increased dyslipidemia and (abdominal) obesity risk in patients with more severe anxiety disorders and depression may be partly explained by chronic low-grade inflammation and smoking. TCAs may increase metabolic risk through enhanced sympathetic and decreased parasympathetic ANS activity. That the HPA axis had no impact in our sample may reflect the possibility that the HPA axis only plays a role in acute stress situations rather than under basal conditions.

Effects of antidepressants, but not psychopathology, on cardiac sympathetic control: a longitudinal study

Increased sympathetic activity has been hypothesized to have a role in the elevated somatic disease risk in persons with depressive or anxiety disorders. However, it remains unclear whether increased sympathetic activity reflects a direct effect of anxiety or depression or an indirect effect of antidepressant medication. The aim of this study was to test longitudinally whether cardiac sympathetic control, measured by pre-ejection period (PEP), was increased by depression/anxiety status and by antidepressant use. Cross-sectional and longitudinal data were from a depression and anxiety cohort: the Netherlands Study of Depression and Anxiety (NESDA). Baseline data of 2838 NESDA subjects (mean age 41.7 years, 66.7% female) and 2-year follow-up data of 2226 subjects were available for analyses. Included were subjects with and without depressive/anxiety disorders, using or not using different antidepressants at baseline or follow-up. The PEP was measured non-invasively by 1.5 h of ambulatory impedance cardiography. Cross-sectional analyses compared PEP across psychopathology and antidepressant groups. Longitudinal analyses compared 2-year changes in PEP in relation to changes in psychopathology and antidepressant use. Cross-sectional analyses showed that antidepressant-naïve depressive/anxious subjects had comparable PEP as controls, whereas subjects using tricyclic (TCA) or combined serotonergic/noradrenergic antidepressants (SNRI) had significantly shorter PEP compared with controls. In contrast, subjects using selective serotonin re-uptake inhibitors (SSRIs) had longer PEP than controls. Longitudinal results confirmed these findings: compared with 2-year change in PEP in continuous non-users (+2 ms), subjects who started TCA or SNRI treatment showed significantly shortened PEP (−11 ms, p=0.005 and p<0.001), whereas subjects who started SSRI treatment showed significant prolongation of PEP (+9 ms, p=0.002). Reversed findings were observed among those who stopped antidepressant use. These findings suggest that depressive and anxiety disorders are not associated with increased cardiac sympathetic control. However, results pose that TCA and SNRI use increases sympathetic control, whereas SSRI use decreases sympathetic control.

Identifying Genetic Variants for Heart Rate Variability in the Acetylcholine Pathway

Heart rate variability is an important risk factor for cardiovascular disease and all-cause mortality. The acetylcholine pathway plays a key role in explaining heart rate variability in humans. We assessed whether 443 genotyped and imputed common genetic variants in eight key genes (CHAT, SLC18A3, SLC5A7, CHRNB4, CHRNA3, CHRNA, CHRM2 and ACHE) of the acetylcholine pathway were associated with variation in an established measure of heart rate variability reflecting parasympathetic control of the heart rhythm, the root mean square of successive differences (RMSSD) of normal RR intervals. The association was studied in a two stage design in individuals of European descent. First, analyses were performed in a discovery sample of four cohorts (n = 3429, discovery stage). Second, findings were replicated in three independent cohorts (n = 3311, replication stage), and finally the two stages were combined in a meta-analysis (n = 6740). RMSSD data were obtained under resting conditions. After correction for multiple testing, none of the SNPs showed an association with RMSSD. In conclusion, no common genetic variants for heart rate variability were identified in the largest and most comprehensive candidate gene study on the acetylcholine pathway to date. Future gene finding efforts for RMSSD may want to focus on hypothesis free approaches such as the genome-wide association study.

Heavy alcohol use, rather than alcohol dependence, is associated with dysregulation of the hypothalamic-pituitary-adrenal axis and the autonomic nervous system.

BACKGROUND Heavy alcohol use as well as alcohol dependence (AD) have been associated with dysregulation of the hypothalamic-pituitary-adrenal (HPA)-axis and the autonomic nervous system (ANS). However, the relative contribution of alcohol use and AD is unclear. METHODS Baseline data were derived from 2947 persons of the Netherlands Study of Depression and Anxiety (NESDA), including non-drinkers (n=498), moderate drinkers (n=2112) and heavy drinkers (n=337). We also distinguished between persons with no lifetime DSM-IV AD (n=2496), remitted AD (> 1 year; n = 243), and current AD (≤ 1 year; n=208). ANS measures included ECG-based heart rate (HR), respiratory sinus arrhythmia (RSA, high RSA reflecting high cardiac parasympathetic control) and pre-ejection period (PEP, high PEP reflecting low cardiac sympathetic control). HPA-axis measures included the cortisol awakening response (area under the curve with respect to the ground [AUCg] and increase [AUCi]), evening cortisol and a 0.5mg dexamethasone suppression test, all measured in saliva. RESULTS Heavy drinkers showed higher basal cortisol levels (AUCg: p=.02; evening cortisol: p=.006) and increased cardiac sympathetic control (higher HR: p=.04; lower PEP: p=.04) compared to moderate drinkers. Persons with current or remitted AD did not differ from persons without lifetime AD on any of the HPA-axis or ANS indicators (all p>.33). Similar patterns of HPA-axis and ANS activity across alcohol use groups were found in persons with and without lifetime AD. CONCLUSIONS Our findings suggest that current heavy alcohol use, rather than current or remitted AD, is associated with hyperactivity of the HPA-axis and increased cardiac sympathetic control.

Increased cortisol awakening response was associated with time to recurrence of major depressive disorder

INTRODUCTION Although HPA-axis activity has been studied extensively in relation to depression, there is no consensus whether HPA-axis parameters predicts major depressive disorder (MDD) recurrence. We investigated whether HPA-axis parameters (cortisol awakening response (CAR), the dexamethasone suppression test (DST) and evening cortisol) predict time to recurrence in remitted subjects with a history of MDD and whether childhood trauma and life events interact with HPA-axis parameters in increasing the risk for recurrence. METHOD Data were derived from 549 subjects with a lifetime diagnosis of MDD in remission for at least six months preceding the baseline assessment of the Netherlands Study of Depression and Anxiety (NESDA). Subjects were followed up with two interviews over the course of four years to assess recurrence. DSM-IV based diagnostic interviews were used to assess time to recurrence of MDD. Seven salivary cortisol samples collected at baseline with information on CAR, evening cortisol and the DST. Hazard ratios were calculated using Cox regression analysis, adjusted for covariates. RESULTS A higher CAR was associated with time to recurrence of MDD (HR=1.03, 95%CI 1.003-1.060, p=0.03) whereas evening cortisol and DST were not. No interactions between HPA-axis parameters and stress-related factors were found. CONCLUSIONS Our data support previous studies reporting that subjects with a higher CAR are more vulnerable to recurrence of MDD.