Is generalized anxiety disorder an anxiety or mood disorder? Considering multiple factors as we ponder the fate of GAD

The diagnostic threshold of generalized anxiety disorder in the community: a developmental perspective

Discussion surrounds the question as to whether criteria for generalized anxiety disorder (GAD) should change, particularly in youth. This study examines the effects of possible criteria changes on GAD prevalence and clinical correlates. DSM-IV GAD was assessed using the M-CIDI in a community sample of adolescents and young adults. Diagnostic thresholds were modified in two age spans (9-20 and 21-34 years) using a person-by-year data file (N = 38,534 cases). Relaxing the duration or excessiveness criteria led to the most pronounced changes in GAD prevalence, while relaxing frequency, uncontrollability, or associated-symptom criteria had smaller effects. A lower duration requirement increased rates more in older than younger age spans. Opposite effects occurred for changes in associated-symptoms or clinical-significance criteria. Broader GAD definitions identified cases in both age spans that appeared mostly milder than DSM-IV cases but that still differed from non-GAD cases in various clinical factors and validators. Developmental aspects require stronger consideration in future diagnostic systems.

Generalized anxiety disorder: clinical presentation, diagnostic features, and guidelines for clinical practice

Generalized anxiety disorder (GAD) is a prevalent and disabling disorder characterised by persistent worrying, anxiety symptoms, and tension. General practitioners and mental healthcare professionals frequently misdiagnose the presenting symptoms. This article addresses the clinical presentation of GAD and provides guidelines for discriminating GAD from other disorders, based on theoretical considerations and clinical experience. Debate relating to the validity of the definition of GAD is discussed, and suggestions are made for improving the criteria for GAD, which may guide future versions of classification systems such as the Diagnostic and Statistical Manual.

Altered cerebral blood flow patterns associated with pathologic worry in the elderly

BACKGROUND

Generalized anxiety disorder (GAD) is the most prevalent anxiety disorder among the elderly and has high functional and cognitive morbidity. However, late-life GAD is relatively understudied and its functional neuroanatomy is uncharted. Several imaging studies have suggested abnormalities in the cognitive control systems of emotion regulation in anxiety disorders in young adults. The aim of this study was to examine the neural correlates of emotion regulation in late-life GAD.

METHOD

We compared 7 elderly GAD subjects and 10 elderly nonanxious comparison subjects using functional MRI. Regional cerebral blood flow (rCBF) was measured using pulsed arterial spin labeling perfusion MRI at rest and during an emotion regulation paradigm.

RESULTS

Relative to the rest condition, elderly nonanxious comparison subjects had increased rCBF during worry induction (WI) in the right insula, bilateral amygdala, and associative temporooccipital areas. Elderly GAD subjects had increased rCBF during WI in the associative temporooccipital areas, but not in the insula or the amygdala. During worry suppression (WS), elderly nonanxious comparison subjects had increased rCBF in the prefrontal cortex (PFC) and dorsal ACC. Elderly GAD subjects had no changes in rCBF during WS in the PFC.

CONCLUSIONS

When attempting to regulate their emotional responses, elderly anxious subjects failed to activate prefrontal regions involved in the downregulation of negative emotions. These results, showing that elderly anxious subjects are not effectively engaging the PFC in suppressing worry, may be clinically relevant for developing personalized therapeutic strategies for the treatment of late-life GAD.

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.

Effects of acute tryptophan depletion in serotonin reuptake inhibitor-remitted patients with generalized anxiety disorder

BACKGROUND

Serotonergic antidepressants [selective serotonin reuptake inhibitor (SSRI)] are first-line treatments for generalised anxiety disorder (GAD); however, it is not known if synaptic serotonin (5-HT) availability is important for SSRI efficacy. The present study tested the hypothesis that temporary reduction in central 5-HT transmission, through acute tryptophan depletion (ATD), would reverse the therapeutic effect of the SSRIs in GAD patients.

METHODS

Twelve patients (six males) with GAD, who showed sustained clinical improvement with SSRI treatment, underwent ATD in a double-blind, placebo-controlled, within-subjects design over 2 days, 1 week apart. At the peak time of depletion, the participants inhaled 7.5% CO2 and air in random order for at least 12 min each. Psychological responses were measured using the Spielberger State Anxiety Inventory (STAI-S) and GAD-symptom visual analogue scales (VASs; e.g., worry and tense) and Profile of Mood States.

RESULTS

Free plasma tryptophan to large neutral amino acid (LNAA) ratio decreased by 92% on the depletion day and decreased by 2% on the control day. Irrespective of depletion condition, 7.5% CO(2) inhalation significantly increased STAI-S and GAD-related VAS scores (all p < 0.05) compared with air inhalation. ATD had no effect on any of these measures despite the substantial reduction in free tryptophan/LNAA ratio.

CONCLUSIONS

Although SSRIs treat GAD effectively, the present results suggest that the mechanism of action is different to that seen in panic, social anxiety, and post-traumatic stress disorders. Successful SSRI treatment of GAD may involve long-term receptor changes or alterations in other neurotransmitter systems downstream of serotonin.

Generalized anxiety disorder: between now and DSM-V

This article presents the current evidence base for pharmacotherapy of generalized anxiety disorder (GAD) and an update on the phenomenology of GAD and its association with other psychiatric and somatic conditions. It discusses nosological issues and suggests ways to improve recognition, treatment, and care for patients who have GAD.

Association between generalized anxiety levels and pain in a community sample: evidence for diagnostic specificity

BACKGROUND

It is unclear whether generalized anxiety disorder (GAD) has a specific relationship to pain syndromes, going beyond the established association of pain with anxiety syndromes in general.

METHODS

Mental disorders were assessed in a community sample (N=4181; 18-65 years) using the DSM-IV/M-CIDI. Several threshold definitions were used to define GAD and medically unexplained pain.

RESULTS

The association between pain and GAD (odds ratio, OR=5.8 pain symptoms; OR=16.0 pain disorder) is stronger than the association between pain and other anxiety disorders (OR=2.4 pain symptoms; OR=4.0 pain disorder). This association extends to subthreshold level definitions of GAD with some indication for a non-linear dose-response relationship. The GAD-pain link cannot sufficiently be explained by demographic factors, comorbid mental or physical disorders.

CONCLUSIONS

The association of pain and generalized anxiety is not artifactual. Compared to other anxiety syndromes, it appears to be stronger and more specific suggesting the need to explore clinical and public health implications.

Anticipatory activation in the amygdala and anterior cingulate in generalized anxiety disorder and prediction of treatment response

OBJECTIVE

The anticipation of adverse outcomes, or worry, is a cardinal symptom of generalized anxiety disorder. Prior work with healthy subjects has shown that anticipating aversive events recruits a network of brain regions, including the amygdala and anterior cingulate cortex. This study tested whether patients with generalized anxiety disorder have alterations in anticipatory amygdala function and whether anticipatory activity in the anterior cingulate cortex predicts treatment response.

METHOD

Functional magnetic resonance imaging (fMRI) was employed with 14 generalized anxiety disorder patients and 12 healthy comparison subjects matched for age, sex, and education. The event-related fMRI paradigm was composed of one warning cue that preceded aversive pictures and a second cue that preceded neutral pictures. Following the fMRI session, patients received 8 weeks of treatment with extended-release venlafaxine.

RESULTS

Patients with generalized anxiety disorder showed greater anticipatory activity than healthy comparison subjects in the bilateral dorsal amygdala preceding both aversive and neutral pictures. Building on prior reports of pretreatment anterior cingulate cortex activity predicting treatment response, anticipatory activity in that area was associated with clinical outcome 8 weeks later following treatment with venlafaxine. Higher levels of pretreatment anterior cingulate cortex activity in anticipation of both aversive and neutral pictures were associated with greater reductions in anxiety and worry symptoms.

CONCLUSIONS

These findings of heightened and indiscriminate amygdala responses to anticipatory signals in generalized anxiety disorder and of anterior cingulate cortex associations with treatment response provide neurobiological support for the role of anticipatory processes in the pathophysiology of generalized anxiety disorder.

Core symptoms of major depressive disorder: relevance to diagnosis and treatment

The construct of major depressive disorder makes no etiological assumptions about populations with diverse symptom clusters. "Depressed mood" and "loss of interest or pleasure in nearly all activities" are core features of major depressive episode, though a strong case can be made to pay increasing attention to symptoms of fatigue, sleep disturbance, anxiety, and neurocognitive and sexual dysfunction in the diagnosis and evaluation of treatment outcome. Mood, guilt, work, and interest, as well as psychic anxiety, are consistently identified across validated subscales of the Hamilton Depression Rating Scale as prevalent and sensitive to change with existing treatments. A major limitation of these antidepressant therapies is their narrow spectrum of action. While the core "mood and interest" symptoms have been the main focus of attention, the associated symptoms listed above are often unaffected or exacerbated by current treatments. Careful clinical evaluation should address all of these dimensions, recognizing that improvement may occur sooner in some symptoms (eg, mood) compared with others (eg, sleep disturbance).