Generalized Anxiety Disorder Subjects Research Articles

A Community Epidemiological Survey of Generalized Anxiety Disorder in Hong Kong

Generalized anxiety disorder (GAD) is understudied in Asian communities. There were 3,304 Chinese subjects (aged 15-60 years) randomly drawn from the general population of Hong Kong and successfully interviewed. The participation rate was 65.8%. The six-month prevalence of DSM-IV GAD was 4.1%. Over half of the GAD subjects reported palpitations and bowel symptoms. Comorbid depressive mood (65%) and substance use (35%) were common. Forty-one percent of GAD subjects sought help, usually from general practitioners who prescribed tranquilizers after negative physical investigations. Telephone-based surveys have limitations but provide an affordable and destigmatizing alternative to face-to-face surveys for communities with limited mental health resources.

Superior temporal gyrus volumes in pediatric generalized anxiety disorder

Background: The essential symptoms of generalized anxiety disorder (GAD) are intrusive worry about everyday life circumstances and social competence, and associated autonomic hyperarousal. The amygdala, a brain region involved in fear and fear-related behaviors in animals, and its projections to the superior temporal gyrus (STG), thalamus, and to the prefrontal cortex are thought to comprise the neural basis of our abilities to interpret social behaviors. Larger amygdala volumes were previously reported in pediatric GAD; however, the brain regions involved in social intelligence were not examined in this pilot study. Methods: Magnetic resonance imaging (MRI) was used to measure the STG, thalamus, and prefrontal volumes in 13 medically healthy child and adolescent subjects with generalized anxiety disorder (GAD) and 98 comparison subjects, who were at low familial risk for mood and psychotic disorders. Groups were similar in age, gender, height, weight, handedness, socioeconomic status, and full-scale IQ. Results: The total, white matter, and gray matter STG volumes were significantly larger in GAD subjects compared with control subjects. Thalamus and prefrontal lobe volumes did not differ between groups. Findings of significant side-by-diagnosis interactions for STG and STG white matter volumes suggest that there is a more pronounced right > left asymmetry in total and STG white matter volumes in pediatric GAD subjects compared with control subjects. A significant correlation between the STG white matter percent asymmetry index with the child report of the Screen for Child Anxiety Related Emotional Disorders Scale was seen. Conclusions: These data agree with previous work implicating posterior right-hemispheric regions in anxiety disorders and may suggest developmental alterations in pediatric GAD.

Generalized anxiety disorder in a population aged 80 years and older

To describe the prevalence of generalized anxiety disorder (GAD) in a community-dwelling population aged 80 years and older. Also to compare sleep patterns, cognitive function and prevalence of other psychiatric conditions between healthy controls and GAD subjects. DSM-IV criteria were used to diagnose GAD. A representative random sample of 77 community-dwelling subjects (35%), aged 80 years or more from the rural southern county of Veranopolis, Brazil, was selected. Sleep patterns were assessed using the Pittsburgh Sleep Quality Index and a 2-week sleep/wake diary. Five neuropsychological tests (Buschke-Fuld Selective Reminding Test, CERAD word list, verbal fluency test and two sub-tests of the Wechsler memory scale) were used for cognitive evaluation. The estimated GAD prevalence was 10.6 percent. GAD was associated with major depression, with a significant greater number of depressive symptoms as measured by the Geriatric Depression Scale and with a significant more frequent occurrence of minor depression. Sleeping patterns and cognition function among GAD subjects were not compromised. The severity of physical diseases was similar in both GAD subjects and healthy controls. GAD was associated with a significantly lower health-related quality of life. In comparison with previous studies, the prevalence of GAD is higher in the studied population. This disorder is frequently associated with both depressive symptoms and a lower health-related quality of life.

A pilot study of amygdala volumes in pediatric generalized anxiety disorder

Background: The neurodevelopment of childhood anxiety disorders is not well understood. Basic research has implicated the amygdala and circuits related to these nuclei as being central to several aspects of fear and fear-related behaviors in animals. Methods: Magnetic resonance imaging was used to measure amygdala volumes and comparison brain regions in 12 child and adolescent subjects with generalized anxiety disorder and 24 comparison subjects. Groups were matched on age, sex, height, and handedness and were also similar on measures of weight, socioeconomic status, and full scale IQ. Results: Right and total amygdala volumes were significantly larger in generalized anxiety disorder subjects. Intracranial, cerebral, cerebral gray and white matter, temporal lobe, hippocampal, and basal ganglia volumes and measures of the midsagittal area of the corpus callosum did not differ between groups. Conclusions: Although these data are preliminary and from a small sample, the results are consistent with a line of thinking that alterations in the structure and function of the amygdala may be associated with pediatric generalized anxiety disorder.

Comparing primary and secondary generalized anxiety disorder in a long‐term naturalistic study of anxiety disorders

This study explores the potential differences in comorbidity and course between primary generalized anxiety disorder (GAD), which develops before other anxiety disorders, and secondary GAD. As part of the Harvard/Brown Anxiety Research Project (HARP), a naturalistic, long-term, longitudinal study of 711 subjects from a variety of clinic settings with DSM III-R defined anxiety disorders, 210 subjects with GAD were identified. Of these, 78 (37%) had primary GAD, and 84 (40%) had secondary GAD; of the remainder, 28 (13%) had no other anxiety disorder and 20 (10%) developed GAD within a month of another anxiety disorder and were excluded from the analysis. All subjects were comorbid for at least one other anxiety disorder. Primary GAD subjects were more likely to be in episode at intake (90% vs. 77%, P=.04) and less likely than secondary GAD subjects to have current or past agoraphobia without panic disorder (3% vs. 11%, P=.04), social phobia (19% v. 52%, P=.001), simple phobia (14% v. 30%, P=.02), or post traumatic stress disorder (5% vs. 20%, P=.01). Subjects with primary GAD were also less likely to have current or past alcohol use disorders (17% vs. 37%, P=.004) or major depressive disorder (60% vs. 76%, P=.03). There were no significant differences in either treatment approaches or remission rates for primary compared to secondary GAD. Whether GAD first occurs before or after another anxiety disorder, it is similar in terms of prevalence, treatment, and course. The only significant differences between primary and secondary GAD lie in the rates of comorbidity of both other anxiety disorders and non-anxiety disorders, including major depression and substance abuse. These results support the concept of GAD as a valid, separate and distinct entity, whether it occurs primarily or secondarily. Depression and Anxiety 10:1–7, 1999. © 1999 Wiley-Liss, Inc.

Comparing primary and secondary generalized anxiety disorder in a long-term naturalistic study of anxiety disorders

This study explores the potential differences in comorbidity and course between primary generalized anxiety disorder (GAD), which develops before other anxiety disorders, and secondary GAD. As part of the Harvard/Brown Anxiety Research Project (HARP), a naturalistic, long-term, longitudinal study of 711 subjects from a variety of clinic settings with DSM III-R defined anxiety disorders, 210 subjects with GAD were identified. Of these, 78 (37%) had primary GAD, and 84 (40%) had secondary GAD; of the remainder, 28 (13%) had no other anxiety disorder and 20 (10%) developed GAD within a month of another anxiety disorder and were excluded from the analysis. All subjects were comorbid for at least one other anxiety disorder. Primary GAD subjects were more likely to be in episode at intake (90% vs. 77%, P = .04) and less likely than secondary GAD subjects to have current or past agoraphobia without panic disorder (3% vs. 11%, P = .04), social phobia (19% v. 52%, P = .001), simple phobia (14% v. 30%, P = .02), or post traumatic stress disorder (5% vs. 20%, P = .01). Subjects with primary GAD were also less likely to have current or past alcohol use disorders (17% vs. 37%, P = .004) or major depressive disorder (60% vs. 76%, P = .03). There were no significant differences in either treatment approaches or remission rates for primary compared to secondary GAD. Whether GAD first occurs before or after another anxiety disorder, it is similar in terms of prevalence, treatment, and course. The only significant differences between primary and secondary GAD lie in the rates of comorbidity of both other anxiety disorders and non-anxiety disorders, including major depression and substance abuse. These results support the concept of GAD as a valid, separate and distinct entity, whether it occurs primarily or secondarily.

Comorbidity as a fundamental feature of generalized anxiety disorders: results from the National Comorbidity Study (NCS).

Generalized anxiety disorder (GAD) is a relatively common mental disorder in the general population, afflicting approximately 3% of community residents during their lifetime. It is not a benign condition, since significantly increased disability and dysfunction are found in GAD subjects compared to non-GAD subjects. For decades GAD has frequently been observed in the context of other mental and substance abuse disorders. Initially the weight of clinical opinion indicated that GAD was a residual disease which should only be diagnosed when other mental disorders are not present. More recently there has been a growing recognition that comorbidity is a fundamental characteristic of the course and nature of GAD. In a series of secondary analyses conducted in subjects in the National Comorbidity Study database, we found that 8 out of 10 subjects with lifetime GAD also had a comorbid mood disorder during their lifetime. We found unipolar disorders to be four times more common in GAD than bipolar disorders (67% vs. 17%), providing indirect support for the previously reported observation that GAD and major depression may share a common genetic diathesis. In addition, our analyses support the conclusion that when comorbid mood disorders are present in GAD, a significant increase in associated disability and dysfunction is also found. Thus this comorbid relationship has important implications for clinical course and outcome.

Utilization of Medical Specialists by Anxiety Disorder Patients

The purpose of this study was to determine the utilization of medical specialists by anxiety disorder patients. The setting was a university's clinical outpatient drug trails for anxiety disorders. The participants were subjects identified by advertisement and diagnosed by psychiatric interviews and, in some instances, also by structured interviews. The main outcome measures were the subject responses on a questionnaire listing medical specialists. A total of 94 subjects were surveyed. Primary care physicians (family medicine and internal medicine) were seen more often by panic disorder (PD) subjects than by obsessive-compulsive disorder (OCD) or generalized anxiety disorder (GAD) subjects. Gastroenterologists were seen most frequently by the GAD subjects; dermatologists and cardiologists by the OCD subjects; and otolaryngologists, obstetricians-gynecologists, neurologists, and urologists by the PD subjects. The PD subjects saw more specialists than the subjects with the other disorders. Medical specialists need to increase identification of patients with various anxiety disorders to relieve suffering, improve health care practices, and obtain favorable cost:benefit ratios.

Platelet I 1-imidazoline binding sites are elevated in depression but not generalized anxiety disorder

Depressed patients have been reported to have a higher than normal density of platelet binding sites for 3H-clonidine, an alpha 2-adrenoceptor agonist. Paradoxically, other studies using 3H-alpha 2, antagonists have found no differences from controls. Because 3H-clonidine interacts with platelet alpha 2-adrenoceptors to form G-protein complexes, whereas 3H-alpha 2-antagonists bind with uncoupled receptors, an elevation in G-protein coupling might explain this paradox. Another possibility is that depression might be associated with increased non-adrenergic I1-imidazoline binding sites, which are also clonidine sensitive. To distinguish these possibilities, we utilized p125I-clonidine to measure density (Bmax) and affinity (KD) of platelet G-protein coupled alpha 2-adrenoceptors as well as platelet I1 binding sites, and compared diagnostic groups of major depressive disorder (MDD), generalized anxiety disorder (GAD) and healthy subjects. Specific inhibition of binding by norepinephrine (NE = 10 microM) was used to selectively quantify alpha 2-adrenoceptors, whereas inhibition by 10 microM moxonidine (a > 100-fold selective I1 ligand) quantified I1 binding sites under a NE mask. I1 sites were found to be markedly elevated by, on average, +136% in MDD patients (p = .0007), whereas there was only a marginal increase in alpha 2-adrenoceptor Bmax values in MDD patients (p = .08; GAD and healthy subjects did not differ). Treatment of MDD patients for 6-8 weeks with desipramine downregulated I1 sites as well as alpha 2-adrenoceptors. Positive correlations were also noted for both sites: (a) between Bmax values and the severity of depression (using the Hamilton Depression Rating Scale); and (b) between end-of-treatment plasma desipramine concentrations and the extent of downregulation in Bmax values when subject groups were pooled. None of the binding parameters was associated with plasma catecholamine concentrations. The results suggest that an increased density of platelet I1 binding sites may partially explain the utility of radiolabeled clonidine as a potential biological marker for depressive illness, although an additional increase in G-protein coupling cannot be excluded.

Autonomic characteristics of generalized anxiety disorder and worry

Autonomic characteristics of generalized anxiety disorder (GAD) and worry were examined using measures of heart period variability. The cardiorespiratory responses of 34 GAD clients and 32 nonanxious control subjects were recorded during resting baseline, relaxation, and worry periods. Results indicated differences between GAD subjects and controls as well as among baseline, relaxation, and worry periods. GAD clients exhibited shorter cardiac interbeat intervals (IBIs) and lower high frequency spectral power across all task conditions. Relative to baseline and relaxation conditions, worry was associated with (1) shorter IBIs, (2) smaller mean successive differences (MSD) of the cardiac IBIs, and (3) lower high frequency spectral power. These findings suggest that GAD and its cardinal feature (worry), are associated with lower cardiac vagal control. The findings of the present study provide evidence for the utility of further exploration of the role of autonomic nervous system activity in GAD.

Perceived functions of worry among generalized anxiety disorder subjects: Distraction from more emotionally distressing topics?

Theories regarding worry have discussed both adaptive and maladaptive functions. The present study used rating scales of the six reasons for worry commonly reported by generalized anxiety disorder (GAD) clients to explore subjective perceptions of the functions of worry held by college student worriers meeting self-reported criteria for GAD and by control subjects. Subjects rated motivation, preparation for the worst, and avoidance/prevention of negative outcomes as the most typical reasons for their worry. However, the GAD group was discriminated from other comparison groups particularly by high ratings of “distraction from more emotional topics” as a reason for their worry.

Generalized anxiety disorder vs. panic disorder. Distinguishing characteristics and patterns of comorbidity.

In order to examine the validity of the distinction between generalized anxiety disorder (GAD) and panic disorder (PD) we compared 41 subjects with GAD and 71 subjects with PD. The GAD subjects had never had panic attacks. In contrast to the symptom profile in PD subjects suggestive of autonomic hyperactivity, GAD subjects had a symptom pattern indicative of central nervous system hyperarousal. Also, subjects with GAD had an earlier, more gradual onset of illness. In terms of coexisting syndromes, GAD subjects more often had simple phobias, whereas PD subjects more commonly reported depersonalization and agoraphobia. GAD subjects more frequently had first-degree relatives with GAD, whereas PD subjects more frequently had relatives with PD. A variety of measures indicated that our GAD subjects had a milder illness than those with PD. Also, fewer GAD subjects gave histories of major depression than did PD subjects. Among GAD subjects, coexisting major depression was associated with simple phobia and thyroid disorders and among PD subjects, comorbid depression was associated with social phobia and hypertension. Our findings indicate that the separation of GAD from PD is a valid one. They also indicate that, within disorders, unique patterns of comorbidity may exist that are important both clinically and theoretically.

Qualitative dimensions of worry in DSM-III-R generalized anxiety disorder subjects and nonanxious controls

Revisions to DSM-III cite apprehensive expectation or ‘worry’ as a defining feature of generalized anxiety disorder (GAD). The quality and focus of worry reported by groups of GAD patients ( n = 19), and nonanxious ‘controls’ ( n = 26) were examined using self-monitored data. Content categorizations by independent raters showed that GAD patients worried more about illness, health and injury issues and displayed a tendency to worry more about miscellaneous ‘minor’ issues. These descriptor ratings differentiated the worries of GAD patients from those of non-anxious controls: perceived control over worrying, the extent to which the worry was considered realistic, and perceived success with which worry was alleviated using corrective/preventative actions. The data are related to the DSM-III-R criteria for GAD and to conceptualizations of the nature of excessive worry.