Anxiety, Generalized Anxiety Disorder (GAD)

Article Author:
Sadaf Munir
Article Editor:
James Hughes
Updated:
10/27/2018 12:31:36 PM
PubMed Link:
Anxiety, Generalized Anxiety Disorder (GAD)

Introduction

Generalized anxiety disorder is one of the most common mental disorders. Up to 20% of adults are affected by anxiety disorders each year. Generalized anxiety disorder produces fear, worry, and a constant feeling of being overwhelmed. Generalized anxiety disorder is characterized by persistent, excessive, and unrealistic worry about everyday things. This worry could be multifocal such as finance, family, health, and the future. It is excessive, difficult to control, and is often accompanied by many non-specific psychological and physical symptoms. The excessive worry is the central feature of generalized anxiety disorder.

Diagnostic criteria in the Diagnostic and Statistical Manual of Mental Disorders, fourth edition (DSM-IV) include the following:

  • Excessive anxiety and worry for at least six months
  • Difficulty controlling the worrying.

Anxiety and worry associated with at least three of the following:

  • Restlessness or feeling keyed up or on edge
  • Being easily fatigued, difficulty in concentrating or mind going blank, irritability
  • Muscle tension
  • Sleep disturbance.

Etiology

The etiology may include:

  • Stress
  • Physical condition such as diabetes or other comorbidities such as depression
  • Genetic, first-degree relatives with generalized anxiety disorder (25%)
  • Environmental factors such as child abuse
  • Substance abuse.

Epidemiology

Childhood anxiety occurs in about one-in-four children at some time between the ages of 13 and 18 years. The median age at onset is 11 years.  However, the lifetime prevalence of a severe anxiety disorder in children 13 to 18 is approximately 6%. General prevalence in children younger than 18 years is between 5.7% and 12.8%. The prevalence is approximately twice as high among women as among men.

The American Psychiatric Association first introduced the diagnosis of generalized anxiety disorder two decades ago in the DSM-III. Before that time, generalized anxiety disorder was conceptualized as one of the two core components of anxiety neurosis, the other being panic. A recognition that generalized anxiety disorder and panic, although often occurring together, are sufficiently distinct to be considered independent disorders led to their separation in the DSM-III.

The DSM-III definition of generalized anxiety disorder required uncontrollable and diffuse (i.e., not focused on a single major life problem) anxiety or worry that is excessive or unrealistic in relation to objective life circumstances and that persists for one month or longer. Several related psychophysiological symptoms also were required to occur with the anxiety or worry for a diagnosis of generalized anxiety disorder. Early clinical studies evaluating DSM-III according to this definition in clinical samples found that the disorder seldom occurred in the absence of some other comorbid anxiety or mood disorder. Comorbidity of generalized anxiety disorder and major depression was especially strong and led some commentators to suggest that generalized anxiety disorder might better be conceptualized as a prodrome, residual, or severity marker than as an independent disorder. The rate of comorbidity of generalized anxiety disorder with other disorders decreases as the duration of generalized anxiety disorder increases. Based on this finding, the DSM-III-R committee on generalized anxiety disorder recommended that the duration requirement for the disorder be increased to six months. This change was implemented in the final version of the DSM-III-R. Additional changes in the definition of excessive worry and the required number of associated psychophysiological symptoms were made in the DSM-IV.

These changes in diagnostic criteria led to delays in cumulating data on the epidemiology of generalized anxiety disorder. Nonetheless, such data became available over the past decade. As described in more detail later, these new data challenged the view that generalized anxiety disorder should be conceptualized as a prodrome, residual, or severity marker of other disorders. Instead, the data suggest that generalized anxiety disorder is a common disorder that, although often comorbid with other mental disorders, does not have a rate of comorbidity that is higher than those found in most other anxiety or mood disorders. The new data also challenge the validity of the threshold decisions embodied in the DSM-IV.

Pathophysiology

The exact mechanism is not entirely known. Noradrenergic, serotonergic, and other neurotransmitter systems are believed to play a role in the body's response to stress. The serotonin system and the noradrenergic systems are common pathways involved in anxiety. Many believe that low serotonin system activity and elevated noradrenergic system activity are responsible for its development. It is, therefore, selective serotonin reuptake inhibitors (SSRI) and serotonin-norepinephrine reuptake inhibitors (SNRI) that are the first-line agent for its treatment. Anxiety can be a normal phenomenon in children. Stranger anxiety begins at seven to nine months of life.

History and Physical

Patients with anxiety can pose a diagnostic challenge. Somatic symptoms are more common than psychologic symptoms. Most patients present with vague or nonspecific somatic complaints. Somatic symptoms include shortness of breath, palpitations, fatigability, headache, dizziness, and restlessness. Most patients present with vague or nonspecific somatic complaints. Psychologic symptoms such as excessive, nonspecific anxiety and worry, feeling on edge, difficulty concentrating irritability, and sleeping difficulty.

Evaluation

Assessment begins by initially addressing behavior or somatic symptoms. Evaluate for psychosocial stress, psychosocial difficulties, and developmental issues. Review past medical history such as trauma, psychiatric conditions, and substance abuse.

Generalized Anxiety Disorder 7-Item (GAD-7) Questionnaire. This tool can be used to screen as well as to monitor outcome in patients with generalized anxiety disorder.

The following evaluation may be obtained to exclude organic causes:

  • Thyroid function tests
  • Blood glucose level 
  • Echocardiography
  • Toxicology screen

Multidimensional Anxiety Scale for Children

Child Anxiety Related Emotional Disorders (SCARED)

Treatment / Management

The two main treatments for generalized anxiety disorder are cognitive behavior therapy and medications. Patients may benefit most from a combination of the two. It may take some trial and error to discover which treatments work best.

Cognitive Behavioral Therapy

This includes psychoeducation, changing maladaptive thoughts patterns, and gradual exposure to anxiety-provoking situations.

Pharmacotherapy

Several types of medications are used to treat generalized anxiety disorder.

Antidepressants

Selective serotonin reuptake inhibitor (SSRI) and serotonin-norepinephrine reuptake inhibitor (SNRI) classes are the first-line agents with a response rate of 30% to 50%. This class of drugs includes escitalopram (Lexapro), duloxetine (Cymbalta), venlafaxine (Effexor XR) and paroxetine (Paxil, Pexeva). In a study, 81% of children with anxiety disorders who received a combined sertraline hydrochloride and CBT were responded to the treatment.

Benzodiazepines

Examples diazepam and clonazepam are long-acting agents. These agents are used when an immediate reduction of symptoms is desired, or a short-term treatment is needed. Generally, cooperative and compliant patients who are aware that their symptoms have a psychological basis are more likely to respond to benzodiazepines. Since there is a concern for misuse and dependence, patients with a history of alcoholism or drug abuse are not appropriate candidates for this treatment.

Buspirone (BuSpar)

Buspirone is a non-benzodiazepine which does not cause dependency. It is also less sedating than benzodiazepines, and tolerance does not occur at therapeutic doses. This agent has a therapeutic lag in the efficacy of two to three weeks which limits its use.

Pearls and Other Issues

Consider further evaluation for anxiety disorder if an adult is excessively anxious or an infant or child is excessively clingy and difficult to console during the pediatric visit. Many medical conditions may mimic anxiety disorders. One should distinguish between the anxiety and the illness and should evaluate for organic diseases before making this diagnosis.