Generalized Anxiety Disorder
last authored: Feb 2012, David LaPierre
last reviewed:
Introduction
Generalized Anxiety Disorder (GAD) is one of the most common anxiety disorders (Kessler et al, 2005), representing significant, long-term anxiety or worry that occurs in a number of settings and is difficult to control. It appears to be associated with a genetic vulnerability shaped by developmental experience, influenced by the environment, and maintained by maladaptive cognitions and behaviours including avoidance responses.
Julia Gibson, 2010
Anxiety is physiological tension and arousal, leading to cognitive interpretation of threats and avoidance. It can be good in novel situations by heightening awareness and helping prepare for upcoming situations. However, when anxiety occurs in excess, it can have significant impact on social and occupational functioning.
People with GAD are frequent users of the health care system, in part due to many medical symptoms such as chest pain, shortness of breath, dizziness, abdominal pain, palpitations, headache, and others. This can create much cost and inefficiency in the health system.
Generalized Anxiety Disorder (GAD) usually begins during later childhood and early adolescent years, though usually presents in early adulthood. Females have a higher prevalence (2-9%) than males (1-4%).
Causes and Risk Factors
As most people with GAD report having been anxious all their lives, early factors - behavioural inhibition, attachment pattern, parents with anxiety disorder, and parental style/control - appear important.
Risk factors include:
- past history of anxiety or depression
- family history
- stressful life events,
- social isolation
- femal gender (twice the rate as men)
- co-morbid psychiatric conditions:
- panic disorder
- major depression
- alcohol abuse
- personality disorders
Genetics
Genetics appear to account for about 1/3 of GAD, though anxiety disorders as a whole tend to be predisposed
High levels of arousability and emotional reactivity (negative affectivity) appear early
People with GAD tend to overestimate probability of danger
Studies have failed to link worry with specific conditioning events; averse life events are not necessary for the devlopment of GAD.
Signs, Symptoms, and Diagnosis
The DSM-IV TR Criteria for diagnosing GAD include:
A) excessive anxiety and worry occuring most days for at least 6 months, affecting a number of events or activities (e.g., work, school, home life)
B) worry is difficult to control
C) anxiety and worry includes at least three of the following symptoms, whuch are present most days for at least 6 months
- restlessness
- fatigue
- difficulty concentrating
- irritability
- muscle tension
- sleep disturbance
D) there is no more specific focus for worry (such as occurs in panic disorder or phobia)
E) symptoms cause significant distress and poor functioning
F) symptoms are not due to substance abuse, a general medical condition, mood disorder, psychotic disorder, or pervasive developmental disorder
Always assess possibility of substance abuse, co-morbid depression, and suicidal ideation.
Screening for Anxiety
A seven-item questionnaire, the GAD-7, has been used and validated in the primary care setting. It can be used by the patient as a self-assessment tool, but needs to be followed up by a clinician for an effective diagnosis to be made.
An even simpler screening questionnaire, the GAD-2 has a high sensitivity and specificity for detecting GAD, as well as panic disorder, social anxiety disorder, and PTSD (Kroenke et al, 2007). The two questions asked are:
- are you feeling nervous, anxious, or on edge?
- are you able to stop or control worrying?
However, as anxiety disorders are complex diseases that require considerable expertise in their treatment, screening should only be considered in the context of a collaborative or a stepped care approach to management in primary care (Skapinakis, 2007).
Pathophysiology
GAD has been described as a deregulated amplifier in regards to the amygdala, which senses danger, and physical symptoms, as noxious.
People become terrified of uncertainty, leading to coping strategies such as perfectionism or superstition.
Worry also creates the illusion of certainty.
Neurotransmitters thought to be involved include norepinephrine, serotonin, and GABA.
Differential Diagnosis
The differential to consider when making a diagnosis of GAD includes:
- depression
- substance abuse
- panic disorder
- specific phobia
- obsessive-compulsive disorder
- adjustment disorder (symptoms of less than three months)
- hypo- or hyperthyroidism
Investigations
It is always prudent to rule out medical causes of anxiety symptoms. Tests to consider include:
- complete blood count
- electrolytes
- creatinine
- TSH
- urinalysis
- electrocardiogram (if symptoms are related to the chest)
- screen for drugs of abuse
Prevention
Treatments
Approaching the subject
Many patients will not like the idea of the health care provider telling them they have an anxiety disorder. It can be helpful to use phrases such as:
- you have a loud alarm system (ie amygdala)
- we've done multiple tests, and we can find nothing wrong
- there may indeed be something else happening (ie cancer), but let's get the GAD out of the way with treatment as we keep going with the appropriate investigations
Counselling and Social supports
One of the most effective treatments for anxiety is cognitive behavioural therapy, in which the association between stimuli, throughts, and emotions are discussed to bring more insight to the patient. According to an Australian study, CBT is extremely cost-effective although widespread use would require policy change sufficient to increase the number of trained therapists (Heuzenroeder et al, 2004).
Educate patients on the commonness of anxiety. Stress-management sessions, either for individuals or in a group, can help people learn to cope while destigmatizing anxiety. Self-help materials can be useful in reinforcing these messages. Community support groups provide education and social interactions.
Encourage lifestyle advice:
- limit caffeine and alcohol intake
- exercise more
- practice good sleep hygeine
- explore relaxation techniques
Medications
Pharmacotherapy for GAD includes the following:
- SSRIs: citalpram, escitalopram, paroxetine, sertraline, fluvoxamine, fluoxetine,
- SNRIs: venlafaxine
- NDRIs: buproprion, mirtazepine
Benzodiazepines such as lorazepam, clonazepam, or diazepam may be used for a short while, (eg for a few weeks) as the above medication is increased and attains it's effect. Patients should clearly be told that this is the case. Benzodiazepines have significiant adverse effects, including side effects, dependence, and withdrawal issues.
Introduce the possibility of side effects carefully, becuase worried patients may be at increased risk of experiencing them and stopping the medication. Minimize this risk by starting at a low dose and gradually titrating upwards.
Consequences and Course
GAD symptoms tend to lessen with age, but it remains a difficult condition to treat. Success depends a great deal on personal ability to cope and on stressors at home, work, etc.
Buist-Bouwman (2005) identified the consequences of GAD, estimating that on average patients lost one month per year in productivity.
People diagnosed with anxiety disorders have important gaps in the mental health care that they receive, including poor adherence to psychoactive medications, poor follow-up by primary care physicians, and "marked underuse" of CBT (Stein et al, 2004).
People with anxiety or depresssion are associated with unhealthy lifestyle choices, such as smoking and lack of exercise, which may contribute to high levels of comorbidity (Bonnet et al, 2005).
Resources and References
Bonnet F, Irving K, Terra JL, Nony P, Berthezene F, Moulin P. 2005. Anxiety and depression are associated with unhealthy lifestyle in patients at risk of cardiovascular disease. Atherosclerosis. 178:339-44.
Heuzenroeder L et al. 2004. Cost-effectiveness of psychological and pharmacological interventions for generalized anxiety disorder and panic disorder. Aust N Z J Psychiatry. 38(8):602-12.
John U, Meyer C, Rumpf HJ, Hapke U. 2004. Smoking, nicotine dependence and psychiatric comorbidity—a population-based study including smoking cessation after three years. Drug Alcohol Depend. 76:287-95.
Kessler et al. 2005. Prevalence, severity, and comorbidity of 12-month DSM-IV disorders in the National Comorbidity Survey Replication. Arch Gen Psychiatry. 62(6):617-27.
Kroenke K, Spitzer RL, Williams JB, Monahan PO, Löwe B. (2007). Anxiety disorders in primary care: prevalence, impairment, comorbidity, and detection. Annals of Internal Medicine 146(5):317-25.
Rollman BL et al. 2005. A randomized trial to improve the quality of treatment for panic and generalized
anxiety disorders in primary care. Arch Gen Psychiatry. 62:1332-41.
Skapinakis P. 2007. The 2-item Generalized Anxiety Disorder scale had high sensitivity and specificity for detecting GAD in primary care. Evid. Based Med. 2007;12;149.
Stein MB, Sherbourne CD, Craske MG, Means-Christensen A, Bystritsky A, Katon W, et al. 2004. Quality of care for primary care patients with anxiety disorders. Am J Psychiatry. 161:2230-7.
 |