Basics
Description
Anxiety disorders are a cluster of diagnoses sharing anxiety as common theme.
- Panic disorder is characterized by recurrent, unexpected panic attacks with at least a month or more of worry or avoidant behavior. Panic disorder can occur with or without agoraphobia.
- Agoraphobia involves anxiety about being in a situation from which escape would be difficult.
- Specific phobia is characterized by an excessive fear of a particular object or situation that is avoided or endured with marked distress.
- Social phobia (Social anxiety disorder) is an irrational fear of negative social evaluation, such as scrutiny by unfamiliar people or performance in unfamiliar situations.
- Obsessive compulsive disorder (OCD) is characterized by obsessions (intrusive, uncontrollable, anxiety-provoking thoughts) that are alleviated by the performance of compulsions.
- Posttraumatic stress disorder (PTSD) is a reaction to a traumatic experience that involves re-experiencing of the trauma through nightmares or flashbacks. The reaction includes increased arousal, emotional numbing, and efforts to avoid reminders of the event.
- Generalized anxiety disorder (GAD) involves persistent and excessive worry pertaining to multiple events or domains that continues for 6 months or more. Physical symptoms of GAD include feelings of restlessness, tiring easily, muscle tension, and sleep disturbance.
Epidemiology
- Anxiety disorders are the most common cluster of mental disorders.
- Anxiety disorders are more common in women.
- Phobic disorders are the most common mental disorder among women in the US.
Prevalence
- Lifetime prevalence of any anxiety disorder in the US is estimated at 30 million individuals.
- Lifetime prevalence of individual anxiety disorders range from 2% to 3% (OCD) to estimates as high as 25% for specific phobia.
Risk Factors
- Family history of anxiety disorders
- Temperamental factors such as behavioral inhibition
- Environmental stressors including emotional, physical, and sexual abuse
Genetics
- Genes involved in serotonin neurotransmission and function of hypothalamic-pituitary-adrenal (HPA) axis may play role in development of anxiety.
- However, genes with large and consistent effects on risk for anxiety disorders have not yet been identified.
Etiology
- Implicated neurotransmitters include norepinephrine, serotonin, dopamine, gamma-aminobutyric acid, and glutamate
- Dysregulation of the HPA axis in PTSD
- Misinterpretation of somatic sensations in panic disorder
Associated Conditions
- In a primary care setting, anxiety and depressive disorders present more commonly together than in isolation.
- Panic disorder and GAD are the anxiety disorders most commonly associated with depression.
Individuals diagnosed with an anxiety disorder have a suicide risk that is significantly greater than the general population (1)[A].
Diagnosis
- See "Description"
- Specific criteria are listed in The Diagnostic and Statistical Manual of Mental Disorders, 4th Edition, Text Revision
- Rule out substance use disorders
- Rule out general medical conditions that cause anxiety
History
- A thorough psychiatric evaluation and family history will inform treatment decisions.
- Specifically evaluate for history of substance use disorders.
- Signs and symptoms:
- Hypervigilance
- Frequent worry
- Panic attacks
- Discrete periods of intense physical symptoms that peak and resolve within a short time.
- Patients will often present to emergency care settings during or following panic attacks.
- Social withdrawal
- Physical symptoms of anxiety and panic include increased heart rate, muscle tension, difficulty sleeping, nausea, chest pain, and difficulty breathing.
- Common obsessions include cleanliness, order, completeness, and fear of aggression.
- Common compulsions include handwashing, ordering, and checking, particularly for safety.
- Examples include door locks and stoves.
Tests
- Screen for drugs of abuse
- Check thyroid-stimulating hormone
Imaging
There is evidence for abnormal activity and connectivity between brain regions involved in fear and worry, including amygdala, hippocampus, and prefrontal cortex.
Differential Diagnosis
- Medical conditions associated with anxiety include disorders of the following systems:
- Cardiovascular
- Pulmonary
- Neurologic
- Endocrine
- Gastrointestinal
- Other psychiatric disorders associated with anxiety:
- Substance intoxication and withdrawal
- Tourette's disorder
- Up to 2/3 of individuals with Tourettes have comorbid OCD
- Other mental disorders including mood disorders, body dysmorphic disorder, hypochondriasis, and personality disorders
Treatment
Benzodiazepines and psychotherapeutic techniques can be used to decrease anxiety while awaiting the full effects of treatment with antidepressant medications or psychotherapy.
Medication
- Antidepressants treat anxiety disorders even in the absence of depressive symptoms.
- Medication generally does not play a role in the treatment of specific phobia.
- Higher doses are generally required for OCD compared to other anxiety disorders.
First Line
- Cognitive behavioral therapy (CBT) is a first-line treatment for all anxiety disorders. OCD generally requires a specialized form called Exposure/Response Prevention (ERP).
- SSRIs and SNRIs are first-line treatments for anxiety disorders (2)[A]. For each disorder, some of the following drugs but not others have an FDA indication. Indications for each drug are listed in parentheses, but note that off-label prescribing is common, and differential efficacy between these medications has not been demonstrated.
- To avoid discontinuation syndromes (headache, dizziness, nausea, etc.), medication should be tapered when discontinued.
- Short-term side effects include headache, anxiety or agitation, GI distress, and fatigue; sexual dysfunction is a common and persisting side effect of SSRIs and SNRIs.
- Fluoxetine (OCD, Panic; start 20 mg PO q.a.m., usual dose range 20-80 mg/day)
- Paroxetine (GAD, OCD, Panic, PTSD, Social phobia; start 20 mg PO q.a.m., usual dose range 20-50 mg/day. Paroxetine ER start 12.5 mg PO q.a.m., usual dose range 12.5-50 mg/day)
- Sertraline (OCD, Panic, PTSD, Social phobia; start 50 mg PO daily, usual dose range 50-200 mg/day)
- Citalopram (start 20 mg PO daily, usual dose range 20-40 mg/day)
- Escitalopram (GAD; start 10 mg PO daily, usual dose range 10-20 mg/day)
- Fluvoxamine (OCD; start 50 mg PO q.h.s., usual dose range 100-300 mg/day divided b.i.d. Fluvoxamine ER start 100 mg PO q.h.s., usual range 100-300 mg/day)
- Venlafaxine XR (GAD, Social phobia, Panic; start 37.5-75 mg PO daily; usual dose range 75-150 mg/day); in addition to side effects associated with SSRIs, venlafaxine has a small dose-related risk of inducing hypertension; desvenlafaxine 50 mg PO daily
- Duloxetine (GAD; start 30 mg PO daily 1 week, increase dose in 30 mg increments, max 120 mg/day)
Second Line
- Buspirone (GAD; initial dose 5-10 mg PO b.i.d., usual dose range 15-40 mg in divided doses)
- Tricyclic antidepressants and monoamine oxidase inhibitors (MAOIs) are generally considered second- or third-line drugs due to a greater side-effect burden and concerns regarding toxicity.
- Other drugs, including mirtazapine, anticonvulsants, and atypical antipsychotics, have some initial evidence of efficacy for some of the anxiety disorders.
- Benzodiazepines are effective for most anxiety disorders but long-term treatment is usually restricted to cases that are resistant to other treatments due to concerns regarding tolerance, withdrawal, abuse, and dependence (3)[A].
Pregnancy and the postpartum period are particularly vulnerable times for the development and worsening of anxiety symptoms (4)[A].
- Pregnancy concerns
- Panic symptoms often improve during pregnancy.
- In vulnerable women, OCD can develop or worsen during pregnancy.
- Pharmacotherapy during pregnancy:
- See "Depression" and "Postpartum Depression" chapters for detailed discussion on antidepressant medications in pregnancy and breastfeeding, because depression and anxiety have significant overlap in pharmacology.
- It is critical to consider the risks of not treating or discontinuing treatment along with the possible risks of treatment.
- Consider avoiding medication during the first 12weeks of gestation and near delivery if possible.
- Smallest effective doses should be used.
- Benzodiazepines should be avoided in the first trimester due to risk of malformations (5)[C].
- MAOIs should not be used during pregnancy.
- Postpartum concerns
- GAD more common in postpartum women.
- Subclinical symptoms of generalized and social anxiety frequently occur during the postpartum period.
- Postpartum women are vulnerable to the development of OCD.
- One particularly common type of obsession centers on fear of harming the baby.
Additional Treatment
General Measures
- CBT
- Relaxation techniques
- Desensitization
- Exposure and response prevention
- Cognitive restructuring
- Patient education
- Group or individual psychodynamic therapy
- Particularly useful with PTSD
Issues for Referral
- Refer to psychotherapist (psychologist, psychiatrist, social worker, or other licensed psychotherapist) according to patient preference and ability to participate in therapy.
- Refer to a psychiatrist for complex, comorbid, severe, or treatment-refractory cases.
- Consider hospitalization for patients with suicidality or extreme difficulty functioning.
Ongoing Care
Prognosis
- With the exception of specific childhood phobias which often remit spontaneously with age, untreated anxiety disorders are chronic and often worsen with time.
- Treatment of OCD complicated both by potential relapse and incomplete response.
- PTSD is often chronic. Up to 1/3 of patients are still symptomatic 10 years after diagnosis.
- Despite this, prognosis for most anxiety disorders with appropriate treatment and follow-up care is good.
- A combination of psychotherapy and pharmacotherapy may be more effective than either treatment alone.
- Supportive psychotherapy may prevent relapse. This is particularly important given the chronic course associated with most anxiety disorders.
- Length of treatment
- Treatment response is comparable for both psychotherapy and pharmacotherapy and may take 6-12 weeks.
- Maintenance therapy recommended for 12-18 months, in some cases longer.
Complications
- Frequent comorbidity with other psychiatric disorders, especially with other anxiety disorders
- Comorbid depressive symptoms are particularly common in postpartum period.
- Insomnia
- Suicidality
- Suicidality must be carefully assessed and is more common when there is a comorbid depressive disorder.
References
1Nepon J, Belik SL, Bolton J. The relationship between anxiety disorders and suicide attempts: Findings from the national epidemiologic survey on alcohol and related conditions. Depress Anxiety. 2010;27(9):791-798. [View Abstract]2Baldwin DS, Anderson IM, Nutt DJ. Evidence-based guidelines for the pharmacological treatment of anxiety disorders: Recommendations from the British Association for Psychopharma-cology. J Psychopharmacol. 2005;19(6):567-596. [View Abstract]3Davidson JR, Feltner DE, Dugar A Management of generalized anxiety disorder in primary care: Identifying the challenges and unmet needs. Prim Care Companion J Clin Psychiatry. 2010;12(2). [View Abstract]4Wenzel A, Haugen EN, Jackson LC. Anxiety symptoms and disorders at eight weeks postpartum. Anxiety Disorders. 2005;19:295-311. [View Abstract]5Wikner BN, Stiller CO, Bergman U. Use of benzodiazepines and benzodiazepine receptor agonists during pregnancy: Neonatal outcome and congenital malformations. Pharmacoepidemiol Drug Saf. 2007;16(11):1203-1210. [View Abstract]
Codes
ICD9
- 300.00 Anxiety state, unspecified
- 300.01 Panic disorder without agoraphobia
- 300.21 Agoraphobia with panic disorder
- 300.29 Specific phobia
- 300.23 Social anxiety disorder or social phobia
- 300.3 Obsessive compulsive disorder (OCD)
- 309.81 Posttraumatic stress disorder (PTSD)
- 300.02 Generalized anxiety disorder (GAD)
- 300.23 Social phobia
- 300.20 Phobia, unspecified
ICD10
- F40.01 Agoraphobia with panic disorder
- F41.0 Panic disorder without agoraphobia
- F41.9 Anxiety disorder, unspecified
- F40.9 Phobic anxiety disorder, unspecified
- F40.298 Other specified phobia
- F40.8 Other phobic anxiety disorders
- F42 Obsessive-compulsive disorder
- F43.10 Post-traumatic stress disorder, unspecified
- F41.1 Generalized anxiety disorder
SNOMED
- 197480006 anxiety disorder (disorder)
- 371631005 panic disorder (disorder)
- 35607004 panic disorder with agoraphobia (disorder)
- 386808001 phobia (finding)
- 25501002 social phobia (disorder)
- 191736004 obsessive-compulsive disorder (disorder)
- 47505003 posttraumatic stress disorder (disorder)
- 21897009 generalized anxiety disorder (disorder)
Clinical Pearls
- Individuals diagnosed with an anxiety disorder have a suicide risk that is significantly greater than the general population.
- The natural response is to avoid anxiety-provoking stimuli but this worsens anxiety disorders.
- Treatment options include antidepressants or anxiolytics and psychotherapy, especially cognitive behavioral therapy.