DSM-IV and beyond: what is generalized anxiety disorder?

Neuroimaging Insights: Kava's (Piper methysticum) Effect on Dorsal Anterior Cingulate Cortex GABA in Generalized Anxiety Disorder

Generalised Anxiety Disorder (GAD) is a prevalent, chronic mental health disorder. The measurement of regional brain gamma-aminobutyric acid (GABA) offers insight into its role in anxiety and is a potential biomarker for treatment response. Research literature suggests Piper methysticum (Kava) is efficacious as an anxiety treatment, but no study has assessed its effects on central GABA levels. This study investigated dorsal anterior cingulate (dACC) GABA levels in 37 adult participants with GAD. GABA was measured using proton magnetic resonance spectroscopy (1H-MRS) at baseline and following an eight-week administration of Kava (standardised to 120 mg kavalactones twice daily) (n = 20) or placebo (n = 17). This study was part of the Kava for the Treatment of GAD (KGAD; ClinicalTrials.gov: NCT02219880), a 16-week intervention study. Compared with the placebo group, the Kava group had a significant reduction in dACC GABA (p = 0.049) at eight weeks. Baseline anxiety scores on the HAM-A were positively correlated with GABA levels but were not significantly related to treatment. Central GABA reductions following Kava treatment may signal an inhibitory effect, which, if considered efficacious, suggests that GABA levels are modulated by Kava, independent of reported anxiety symptoms. dACC GABA patterns suggest a functional role of higher levels in clinical anxiety but warrants further research for symptom benefit. Findings suggest that dACC GABA levels previously un-examined in GAD could serve as a biomarker for diagnosis and treatment response.

The nosologic relationship between generalized anxiety disorder and major depression

Generalized anxiety disorder (GAD) has undergone a series of revisions in its diagnostic criteria that has moved it, nosologically, away from its original affiliation with panic disorder (PD) and closer to major depressive disorder (MDD). This, together with its high comorbidity and putative shared genetic risk with MDD, has brought into question its place in future psychiatric nosology, prompting the planners of Diagnostic and Statistical Manual-V (DSM-V) and International Classification of Diseases-11 (ICD-11) to set up a workgroup tasked to better understand the relationship between GAD and MDD. This review attempts to summarize the extant data to compare GAD and MDD on a series of research validators to explore this relationship. Although insufficient data currently exist for GAD in several key validator classes, tentative conclusions can be drawn on the diagnostic status of GAD in relation to MDD. Although GAD possesses substantial overlap with MDD in the areas of genetics, childhood environment, demographics, and personality traits, this tends to hold true for other anxiety disorders (ADs) as well, with the strongest evidence for PD. Data from life events, personality disorders, biology, comorbidity, and pharmacology are mixed, showing some areas of similarity between GAD and MDD but some clear differences, again with a moderate degree of nonspecificity. Thus, although the bulk of evidence supports a close underlying relationship between them, the relatively nonspecific nature of these findings provides little more reason to question the nosologic validity of GAD in relation to MDD than that of some other anxiety disorders.

Reliability and validity of DSM-IV generalized anxiety disorder features

The reliability of generalized anxiety disorder (GAD) features has been shown to be moderate, based on research utilizing the Anxiety Disorders Interview Schedule for DSM-IV (ADIS-IV), a semi-structured diagnostic interview. This may be a function of the criteria for the diagnosis of GAD, which have undergone much revision since its first inclusion in the Diagnostic and Statistical Manual of Mental Disorders. The reliability and validity of disorder feature ratings were examined in a diverse sample of patients who presented for assessment and treatment of excessive worry, generalized anxiety, or tension at an anxiety specialty clinic and who met criteria for a principal diagnosis of GAD (N=129). Internal consistency of the ratings of excessiveness of worry, uncontrollability of worry, and the associated symptom cluster was moderate to low and varied by disorder feature. Inter-rater reliability for all features of GAD and severity of the disorder varied between good and poor. Additional findings showed that the GAD features, as measured using the ADIS-IV module, have modest to strong convergent validity, varying by feature, and poor discriminant validity when tested against measures of social anxiety. Potential reasons for rater disagreement are discussed. Results are also considered in terms of how they may inform the evolving criteria for GAD in DSM-V.

Genetic and environmental influences on psychiatric comorbidity: a systematic review

BACKGROUND

The purpose of this review is to systematically appraise the peer-reviewed literature about the genetic and environmental determinants of psychiatric comorbidity, focusing on four of the most prevalent types of psychopathology: anxiety disorders, depression, conduct disorder and substance abuse.

METHODS

We summarize existing empirical research on the relative contribution that genetic, nonshared and shared environmental factors make to the covariance between disorders, and evidence about specific genes and environmental characteristics that are associated with comorbidity.

RESULTS

Ninety-four articles met the inclusion criteria and were assessed. Genetic factors play a particularly strong role in comorbidity between major depression and generalized anxiety disorder or posttraumatic stress disorder, while the non-shared environments make an important contribution to comorbidity in affective disorders. Genetic and non-shared environmental factors also make a moderate-to-strong contribution to the relationship between CD and SA. A range of candidate genes, such as 5HTTLPR, MAOA, and DRD1-DRD4, as well as others implicated in the central nervous system, has been implicated in psychiatric comorbidity. Pivotal social factors include childhood adversity/life events, family and peer social connections, and socioeconomic and academic difficulties.

LIMITATIONS

Methodological concerns include the use of clinical case-control samples, the focus on a restricted set of individual-level environmental risk factors, and restricted follow-up times.

CONCLUSIONS

Given the significant mental health burden associated with comorbid disorders, population-based research on modifiable risk factors for psychiatric comorbidity is vital for the design of effective preventive and clinical interventions.

Differential patterns of physical symptoms and subjective processes in generalized anxiety disorder and unipolar depression

Given the substantial comorbidity between generalized anxiety disorder (GAD) and unipolar depressive disorders (UDDs), some have suggested that these disorders be combined in future editions of the DSM. However, decisions regarding nosology should not only account for current manifestations of symptom profiles, but also the potential diagnostic utility of associated characteristics, which, given past research, may suggest greater distinctiveness between these disorder classes. In the present investigation, we examined the role of one-item indices of physical, emotional/motivational, and cognitive symptoms in differentiating GAD from UDDs. We assessed these symptoms with one-item measures in order to provide an initial examination of the viability of these constructs as diagnostic criteria. In Study 1, in an unselected college sample, muscle pains and aches, gastrointestinal symptoms, emotion intensity, and intolerance of uncertainty were associated with GAD symptoms; conversely, low positive affect was associated with UDDs symptoms. In Study 2, we extended these findings to a clinical population and found that muscle pains and aches, positive affect, goal motivation, emotion intensity, and intolerance of uncertainty were higher in GAD than in UDDs.

Generalized worry disorder: a review of DSM-IV generalized anxiety disorder and options for DSM-V

BACKGROUND

Generalized anxiety disorder (GAD) has undergone a series of substantial classificatory changes since its first inclusion in DSM-III. The majority of these revisions have been in response to its poor inter-rater reliability and concerns that it may lack diagnostic validity. This article provides options for the revision of the DSM-IV GAD criteria for DSM-V.

METHOD

First, searches were conducted to identify the evidence that previous DSM Work Groups relied upon when revising the DSM-III-R GAD and the overanxious disorder classifications. Second, the literature pertaining to the DSM-IV criteria for GAD was examined.

CONCLUSIONS

The review presents a number of options to be considered for DSM-V. One option is for GAD to be re-labeled in DSM-V as generalized worry disorder. This would reflect its hallmark feature. Proposed revisions would result in a disorder that is characterized by excessive anxiety and worry generalized to a number of events or activities for 3 months or more. Worry acts as a cognitive coping strategy that manifests in avoidant behaviors. The reliability and validity of the proposed changes could be investigated in DSM-V validity tests and field trials.

Anxiety: its role in the history of psychiatric epidemiology

BACKGROUND

The role played by anxiety in the history of psychiatric epidemiology has not been well recognized. Such lack of understanding retarded the incremental growth of psychiatric research in general populations. It seems useful to look back on this history while deliberations are being carried out about how anxiety will be presented in DSM-V.

METHOD

Drawing on the literature and our own research, we examined work that was carried out during and after the Second World War by a Research Branch of the United States War Department, by the Stirling County Study, and by the Midtown Manhattan Study. The differential influences of Meyerian psychobiology and Freudian psychoanalysis are noted.

RESULTS

The instruments developed in the early epidemiologic endeavors used questions about nervousness, palpitations, sweating, trembling, shortness of breath, upset stomach, etc. These symptoms are important features of what the clinical literature called 'manifest', 'free-floating' or 'chronic anxiety'. A useful descriptive name is 'autonomic anxiety'.

CONCLUSIONS

Although not focusing on specific circumstances as in Panic and Phobic disorders, a non-specific form of autonomic anxiety is a common, disabling and usually chronic disorder that received empirical verification in studies of several community populations. It is suggested that two types of general anxiety may need to be recognized, one dominated by excessive worry and feelings of stress, as in the current DSM-IV definition of Generalized Anxiety Disorder (GAD), and another emphasizing frequent unexplainable autonomic fearfulness, as in the early epidemiologic studies.

Appraisal of activating thoughts in generalized anxiety disorder

Worrying may be an avoidance behaviour preventing the discomfort of imagining future threats. To study the link between phasic physiological activation and thought contents, we recruited 32 generalized anxiety disorder (GAD) patients and 31 controls and asked them to report whatever was in their mind just prior to whenever they were prompted. Half of 20 prompts were triggered by non-specific skin conductance fluctuations (activating thoughts). Controls judged activating thoughts as being less pleasant. GAD participants judged activating thoughts as more anxiety provoking, less relaxing and less controllable. Not the level of activation but the appraisal of activating thoughts in a catastrophic fashion differentiates GAD patients from controls.

Development and validation of the Generalized Anxiety Disorder Inventory (GADI)

The psychometric tools used for the assessment of generalized anxiety disorder (GAD) either do not conform to the current concept of the condition or have important limitations. We aimed to develop and validate a new questionnaire for the assessment of symptom profile and severity of GAD. An original pool of potential scale items was subjected to a series of studies in non-clinical and clinical populations, in order to determine the final composition of the scale. The psychometric properties of the new scale, the Generalized Anxiety Disorder Inventory (GADI), were evaluated using a factor analytic model suitable for ordinal data and the Graded Response Model. The precision of measurement of the GADI was quantified through the item information functions.A total of 197 outpatients and 522 non-clinical subjects participated in four studies and completed the GADI. The final 18-item scale was derived from an original pool of 30 potential items. The GADI showed good reliability, convergent and divergent validity. The scale comprises three factors, relating to cognitive, somatic and sleep symptoms. It accurately distinguished GAD patients from non-patient controls. The cognitive factor also distinguished GAD from other anxiety disorders and depression. The GADI is a useful tool in the assessment of the breadth of symptoms and the severity of generalized anxiety disorder in clinical settings.

Cognitive-behavioral therapy for anxiety in the elderly

Anxiety is a significant problem among the elderly. Due to complexities in the medical management of elderly patients, researchers and clinicians have sought psychosocial alternatives to pharmacotherapy in order to treat anxiety in the elderly. Cognitive-behavioral therapy (CBT) in particular has been investigated as a promising treatment. Research conducted to date has established that CBT produces significant improvement in anxiety symptoms among the elderly. However, there is some concern that CBT does not benefit elderly anxiety patients as much as it does younger patients. Investigators are seeking methods of augmenting or supplementing CBT in order to develop more effective treatments for anxiety in the elderly.

Broadening the definition of generalized anxiety disorder: effects on prevalence and associations with other disorders in the National Comorbidity Survey Replication

Concerns have been raised that the DSM-IV requirements of 6-month duration, excessive worry, and three associated symptoms exclude a substantial number of people with clinically significant anxiety from a diagnosis of generalized anxiety disorder (GAD). We examined the implications of relaxing these three criteria for the estimated prevalence and predictive validity of GAD using nationally representative data from the US National Comorbidity Survey Replication. Relaxing all three criteria more than doubles the estimated prevalence of GAD. Broadly defined GAD significantly predicts the subsequent first onset of a wide range of temporally secondary disorders. The odds of secondary disorders are somewhat smaller for broadly defined than DSM-IV GAD, though few of these differences are statistically significant. Results suggest that subthreshold manifestations of GAD are significantly related to elevated risk of subsequent psychopathology. Further research is needed to determine whether broadening the current diagnostic criteria results in a more valid characterization of GAD.

Should excessive worry be required for a diagnosis of generalized anxiety disorder? Results from the US National Comorbidity Survey Replication

BACKGROUND

Excessive worry is required by DSM-IV, but not ICD-10, for a diagnosis of generalized anxiety disorder (GAD). No large-scale epidemiological study has ever examined the implications of this requirement for estimates of prevalence, severity, or correlates of GAD.

METHOD

Data were analyzed from the US National Comorbidity Survey Replication, a nationally representative, face-to-face survey of adults in the USA household population that was fielded in 2001-2003. DSM-IV GAD was assessed with Version 3.0 of the WHO Composite International Diagnostic Interview. Non-excessive worriers meeting all other DSM-IV criteria for GAD were compared with respondents who met full GAD criteria as well as with other survey respondents to consider the implications of removing the excessiveness requirement.

RESULTS

The estimated lifetime prevalence of GAD increases by approximately 40% when the excessiveness requirement is removed. Excessive GAD begins earlier in life, has a more chronic course, and is associated with greater symptom severity and psychiatric co-morbidity than non-excessive GAD. However, non-excessive cases nonetheless evidence substantial persistence and impairment of GAD, high rates of treatment-seeking, and significantly elevated co-morbidity compared with respondents without GAD. Non-excessive cases also have sociodemographic characteristics and familial aggregation of GAD comparable to excessive cases.

CONCLUSIONS

Individuals who meet all criteria for GAD other than excessiveness have a somewhat milder presentation than those with excessive worry, yet resemble excessive worriers in a number of important ways. These findings challenge the validity of the excessiveness requirement and highlight the need for further research into the optimal definition of GAD.

Toward a validation of a tripartite concept of a putative anxious temperament: psychometric data from a French national general medical practice study

BACKGROUND

Although generalized anxiety disorder (GAD) is currently described as a time-limited state mental disorder, emerging evidence suggests that it is best considered as an exaggeration of a putative "anxious temperament" (AT). It is presently unknown whether it is a distinct or unitary construct of a melange of anxious traits related to Cluster-C personality disorders.

METHODS

As part of a Franco-American collaborative study, we developed the 15-item Operational Criteria for Anxious Personality (OCAP), expanding criteria sets developed earlier by one of us (H.S.A.). The study, which was conducted in the French primary care medical sector, included 1112 young adults (18-40 years), seeking help for isolated anxious complaints, never treated before-and without any diagnosable disorder on the axis I of DSM-IV. As previous papers have reported the preliminary validity of OCAP, especially concurrent validity with the State-Trait Anxiety Inventory (STAI) (Speilberger), in this report, we focus on its full psychometric properties.

RESULTS

The present data indicate a normal distribution of AT items, a satisfactory Chronbach's coefficient (0.64), and the presence at intake of three different subtypes of AT: "anxious-avoidant," "anxious-phobic," and "anxious-sensitive." After a prospective 6-month follow-up, the major criteria of AT were stable in 80% of cases, and for specific AT items, the stability rate varied between 65% and 80%; much of the unstable items were accounted by improvement during naturalistic treatment. The latter could explain the different factor structure obtained at follow-up, which tended to be less heterogeneous, and represented by one global factor.

LIMITATION

We used a categorical (yes/no) rather than a Likert-type gradation of frequency and intensity of anxiousness items and relatively low number of items, especially for those involving worrying about one's own health or that of one's loved ones.

CONCLUSIONS

Anxiousness as a temperamental dimension appears to involve putative subtypes along "worrying," "phobic," "sensitive" (and "avoidant") dimensions.

Generalized Anxiety Disorder and major depressive disorder comorbidity in the National Survey of Mental Health and Well-Being

We report population data on DSM-IV Generalized Anxiety Disorder (GAD) from the Australian National Survey of Mental Health and Well-Being, obtained from a nationwide household survey of adults using a stratified multistage sampling process. A response rate of 78.1% resulted in 10,641 persons being interviewed. Diagnoses were made using the Composite International Diagnostic Interview. The interview was computerised and conducted by trained lay interviewers. We investigated comorbidity between GAD and major depressive disorder (MDD). The results indicate that sociodemographic correlates of GAD, and associated disablement and service use, are influenced by the presence of a comorbid depressive disorder but cannot be fully explained by the presence of that disorder. In addition, GAD was confirmed as significantly disabling, even as a single disorder. We conclude that the results are consistent with the view that GAD has a significant and independent impact on the burden of mental disorders.

Anxiety and depression: a 40-year perspective on relationships regarding prevalence, distribution, and comorbidity

OBJECTIVE

Building on a report about the prevalence of depression over time, this paper examines historical trends regarding anxiety in terms of its prevalence, its distribution by age and gender, and its comorbidity with depression. Methods for conducting such time trend analysis are reviewed.

METHOD

Representative samples of adults were selected and interviewed in 1952, 1970, and 1992. Logistic regressions were used for statistical analysis.

RESULTS

Although twice as common as depression, the prevalence of anxiety was equally stable. Anxiety was consistently and significantly more characteristic of women than men. A re-distribution of rates in 1992 indicated that depression but not anxiety had significantly increased among younger women (P = 0.03). Throughout the study, approximately half of the cases of anxiety also suffered depression.

CONCLUSION

The relationships between anxiety and depression remained similar over time with the exception that depression came to resemble anxiety as a disorder to which women were significantly more vulnerable than men. Social and historical factors should be investigated to assess their relevance to this change.

Pathological worry in depressed and anxious patients

Anxious apprehension is present in all anxiety disorders and concerns have been raised that worry is not confined to Generalized Anxiety Disorder (GAD). The aims of the present project were three-fold. First, we reexamined whether the level of pathological worry is higher in patients with GAD than other anxiety disorders. Second, we compared worry scores of patients with "pure" GAD, "pure" MDD, and MDD with comorbid GAD. And third, to examine whether worry is specific to psychopathology in general rather than anxiety or depression, we included a control group (psychiatric outpatients without an affective or anxiety disorder). Twelve hundred outpatients were interviewed and completed the Penn State Worry Questionnaire (PSWQ) upon presentation for treatment. Patients with "pure" GAD had the highest scores. Depressed patients were similar to those with anxiety disorders other than GAD, and the control group showed worrying similar to that in general population and nonanxious samples.

Vocalizations during withdrawal from opiates and cocaine: possible expressions of affective distress

Intense anxiety has been postulated to trigger relapse to abuse of opiates and psychomotor stimulants. Preclinical research methodologies need to be developed to adequately characterize the affective or emotional component of withdrawal. Classically, withdrawal from psychomotor stimulants and opiates focuses on somatic and autonomic indices, foremost based on observational assessments and, additionally, on measures of disrupted conditioned behavior. These measures depict the intensity and time course of withdrawal from specific doses of opiates and psychomotor stimulants, but require large numbers of subjects due to single use of each individual. Behavioral disruptions have been attributed to anhedonia, a core symptom of drug withdrawal, as well as major depressive and psychotic disorders. In spite of some pharmacological validation, inferences about anxiety-like disturbances, based on observed somatic and autonomic signs or on changes in conditioned responses, have to remain tentative. High-pitched vocalizations may communicate affective expressions and, in rodents, different kinds of ultrasonic vocalizations communicate maternal separation distress in infants, accompany the intensely arousing phases of agonistic confrontations, signal submission and distress in defensive responses to threats and painful events, and are part of the excitatory and inhibitory phases of sexual behavior. While acute treatment with opiates, psychomotor stimulants, alcohol and benzodiazepines suppresses ultrasonic vocalizations in the 22-25-kHz range, rats emit high rates of ultrasonic vocalizations upon withdrawal from prolonged exposure to these drugs, particularly if they have been startled. Peak rates of ultrasonic distress calls occur ca. 1-3 days after cessation of cocaine or opiate treatment and decline within 5-7 days. Ultrasonic vocalizations during withdrawal from cocaine, alcohol or benzodiazepines can be attenuated by renewed access to the drug. It will be informative to learn how the neural circuit mediating vocalizations interacts with the ones subserving self-administration of alcohol, opiates and psychomotor stimulants.

Sleep disturbance in generalized anxiety disorder and its treatment

Sleep laboratory and epidemiological studies indicate that insomnia is a frequent finding in patients with psychiatric disorders. In this respect, insomnia associated with a major depression or an anxiety disorder, mainly generalized anxiety disorder (GAD), is the most prevalent diagnosis. According to available evidence, the sleep disturbance associated with mild-to-moderate GAD is a sleep-maintenance insomnia, and to a lesser extent a sleep-onset insomnia. Insomnia associated with mild-to-moderate GAD generally responds to psychological treatments and anxiolytic benzodiazepines. Moreover, concomitant administration of hypnotic medication can be contemplated in patients with severe GAD.