Generalized Anxiety Disorder: A Review of Recent Findings

Generalized Anxiety Disorder in Canadian Adults: to what Extent Might Social Support Subdomains and Negative Social Interactions Predict Psychological Distress?

Generalized anxiety disorder (GAD) may involve persistent and unwarranted anxiety, fear, and rumination, combined with various somatic symptoms (e.g., fatigue, dizziness, muscle tension, and nausea) which may compel many to withdraw socially. While studies report an inverse relationship between social support and psychological distress among adults with GAD, those that assess the distinct influence of negative social relations, particularly by sex are limited. The primary aims of this study were to (a) assess and compare respondents with a lifetime of GAD in terms of levels of perceived social support (using the Social Provisions Scale - 10 Items (SPS-10) Scale), negative social interactions (using the Negative Social Interaction (NSI) Scale) and psychological distress (using the Kessler Psychological Distress Scale (K10)), and (b) determine whether SPS-10 subdomains and NSIs predict psychological distress. Compared with a matched sample without GAD, respondents with GAD were more likely to be single, divorced, and have lower incomes. Respondents with GAD also had lower overall SPS-10 scores, and lower scores for each subdomain (i.e., 'guidance', 'reliable alliance', 'reassurance of worth', 'attachment', and 'social integration'), and higher NSI and K10 scores. Although no difference in psychological distress was observed between men and women with GAD, men had lower SPS-10 scores (overall and for each subdomain), while women had higher NSIs scores. A subsequent hierarchical regression for respondents with GAD revealed that 'social integration' and 'reassurance of worth' predicted lower psychological distress, while higher NSI scores predicted higher psychological distress. Finding implications and future research are discussed.

Risk Factors, Clinical Presentations, and Functional Impairments for Generalized Anxiety Disorder in Military Personnel and the General Population in Canada

OBJECTIVE

This study sought to examine differences in sociodemographic risk factors, comorbid mental conditions, clinical presentations, and functional impairments associated with past-year generalized anxiety disorder (GAD) between Canadian Armed Forces (CAF) Regular Force personnel and the Canadian general population (CGP).

METHOD

Data were from 2 nationally representative surveys collected by Statistics Canada: 1) the Canadian Community Health Survey on Mental Health, collected in 2012 ( N = 25,113; response rate = 68.9%); and 2) the Canadian Forces Mental Health Survey, collected in 2013 ( N = 8,161; response rate = 79.8%).

RESULTS

The prevalence of lifetime and past-year GAD was significantly higher in the CAF (12.1% and 4.7%) than in the CGP (9.5% and 3.0%). Comorbid mental disorders were strongly associated with GAD in both populations. Although the content area of worry and the GAD symptoms endorsed were similar, CAF personnel were significantly more likely to endorse specific types of worries (i.e., success at school/work, social life, mental health, being away from home or loved ones, and war or revolution) and specific symptoms of GAD (i.e., restless, keyed up, or on edge and more irritable than usual) than civilians, after adjusting for sociodemographic covariates and comorbid mental disorders. CAF personnel with past-year GAD reported significantly higher functional impairment at home than civilians with past-year GAD.

CONCLUSION

GAD is a substantial public health concern associated with significant impairment and disability in both military and civilian populations. GAD in military and civilian populations shows similarities and differences: Key similarities include its extensive comorbidity and significant functional impairment, whereas key differences include the focus of worries and symptom profile.

Vilazodone in patients with generalized anxiety disorder: a double-blind, randomized, placebo-controlled, flexible-dose study

Vilazodone is a selective serotonin reuptake inhibitor and a 5-HT1A receptor partial agonist that is approved for treatment of major depressive disorder in adults in the USA and Mexico. The efficacy, safety, and tolerability of vilazodone for generalized anxiety disorder (GAD) were investigated in a clinical trial (NCT01766401 ClinicalTrials.gov). Participants (18-70 years, inclusive) who met Diagnostic and Statistical Manual of Mental Disorders, 4th ed., text revision, criteria for GAD were randomized (1:1) to placebo or flexible-dose vilazodone (20-40 mg/day) for 8 weeks of double-blind treatment. Primary and secondary efficacy parameters were changes from baseline to week 8 in Hamilton Rating Scale for Anxiety and Sheehan Disability Scale total scores, respectively. Analysis was based on a mixed-effects model for repeated measures approach on the intent-to-treat population. The intent-to-treat population comprised 395 patients (placebo=197, vilazodone=198); 77% completed the study. The least squares mean difference in change from baseline to week 8 in the Hamilton Rating Scale for Anxiety total score was statistically significant for vilazodone versus placebo [-1.50 (-2.96, -0.04), P=0.0438]. The mean change from baseline to week 8 in the Sheehan Disability Scale total score for vilazodone versus placebo was not statistically significant. Adverse events were reported in 60% of placebo-treated and 83% of vilazodone-treated patients. This was a positive clinical trial of 20-40 mg/day vilazodone versus placebo in the treatment of GAD.

A double-blind, randomized, placebo-controlled, fixed-dose phase III study of vilazodone in patients with generalized anxiety disorder

BACKGROUND

Vilazodone, a selective serotonin reuptake inhibitor and 5-HT1A receptor partial agonist, is approved for treating major depressive disorder in adults. This study (NCT01629966 ClinicalTrials.gov) evaluated the efficacy and safety of vilazodone in adults with generalized anxiety disorder (GAD).

METHODS

A multicenter, double-blind, parallel-group, placebo-controlled, fixed-dose study in patients with GAD randomized (1:1:1) to placebo (n = 223), or vilazodone 20 mg/day (n = 230) or 40 mg/day (n = 227). Primary and secondary efficacy parameters were total score change from baseline to week 8 on the Hamilton Rating Scale for Anxiety (HAMA) and Sheehan Disability Scale (SDS), respectively, analyzed using a predefined mixed-effect model for repeated measures (MMRM). Safety outcomes were presented by descriptive statistics.

RESULTS

The least squares mean difference (95% confidence interval) in HAMA total score change from baseline (MMRM) was statistically significant for vilazodone 40 mg/day versus placebo (-1.80 [-3.26, -0.34]; P = .0312 [adjusted for multiple comparisons]), but not for vilazodone 20 mg/day versus placebo. Mean change from baseline in SDS total score was not significantly different for either dose of vilazodone versus placebo when adjusted for multiplicity; significant improvement versus placebo was noted for vilazodone 40 mg/day without adjustment for multiplicity (P = .0349). The incidence of adverse events was similar for vilazodone 20 and 40 mg/day (∼71%) and slightly lower for placebo (62%). Nausea, diarrhea, dizziness, vomiting, and fatigue were reported in ≥5% of patients in either vilazodone group and at least twice the rate of placebo.

CONCLUSIONS

Vilazodone was effective in treating anxiety symptoms of GAD. No new safety concerns were identified.

From the stressed adolescent to the anxious and depressed adult: investigations in rodent models

Anxiety and depression are the most prevalent of the psychiatric disorders. The average age of onset of these disorders is in adolescence, and stressful experiences are recognized as an important pathway to such dysfunction. Until recently, however, most animal models of these disorders involved adult males. We provide a brief overview of anxiety and depression and the extent to which adolescent rodents are a valid model for their investigation, and briefly review the main measures of anxiety-like and depressive behaviour in rodents. The focus of the review is investigations in which adolescent rodents were exposed to chronic stressors, describing our research using social instability stress and that of other researchers using various social and non-social stressors. The evidence to date suggests stress in adolescence alters the trajectory of brain development, and particularly that of the hippocampus, increasing anxiety and depressive behaviour in adulthood.