Anxiety disorder

Anxiety disorder is a blanket term covering several different forms of abnormal and pathological fears and anxieties which only came under the aegis of psychiatry at the very end of the 19th century.^[1] Current psychiatric diagnostic criteria recognize a wide variety of anxiety disorders. Recent surveys have found that as many as 18% of Americans may be affected by one or more of them.^[2]

Diagnosis

Anxiety disorders are often debilitating chronic conditions, which can be present from an early age or begin suddenly after a triggering event. They are prone to flare up at times of high stress and are frequently accompanied by physiological symptoms such as headache, sweating, muscle spasms, palpitations, and hypertension, which in some cases lead to fatigue or even exhaustion.

Although in casual discourse the words anxiety and fear are often used interchangeably, in clinical usage, they have distinct meanings; anxiety is defined as an unpleasant emotional state for which the cause is either not readily identified or perceived to be uncontrollable or unavoidable, whereas fear is an emotional and physiological response to a recognized external threat. The term anxiety disorder, however, includes fears as well as anxieties. Indeed, phobias (fears which are "persistent or irrational") constitute the majority of anxiety disorder cases.

Anxiety disorders are often comorbid with other mental disorders, particularly clinical depression, which may occur in as many as 60% of people with anxiety disorders. The fact that there is considerable overlap between symptoms of anxiety and depression, and that the same environmental triggers can provoke symptoms in either condition, may help to explain this high rate of comorbidity.^[3]

Studies have also indicated that anxiety disorders are more likely among those with family history of anxiety disorders, especially certain types.^[4]

Sexual dysfunction also often accompanies anxiety disorders, although it is difficult to determine whether anxiety causes the sexual dysfunction, or whether they arise from a common cause. The most common manifestations in individuals with anxiety disorder are avoidance of intercourse, premature ejaculation or erectile dysfunction among men and pain during intercourse among women. Sexual dysfunction is particularly common among people affected by panic disorder (who may fear that a panic attack will occur during sexual arousal) and posttraumatic stress disorder.^[5]

Causes and contributing factors

Clinical and animal studies suggest a correlation between anxiety disorders and difficulty in maintaining balance.^[6][7][8][9] A possible mechanism is malfunction in the parabrachial nucleus, a brain structure that, among other functions, coordinates signals from the amygdala with input concerning balance. The amygdala is involved in the emotion of fear.^[10]

Especially the basolateral amygdala has been implicated in anxiety generation. A relationship between anxiety and dendritic arborization of the amygdaloid neurons is well known. SK2 potassium channels mediate inhibitory influence on action potentials and reduce arborization. By overexpressing SK2 in the basolateral amygdala, anxiety was reduced and stress-induced corticosterone secretion at a systemic level decreased in an animal model.^[11] Mutations in related SK3 are suspected to be a possible underlying cause for several neurological disorders, including anxiety.^{[citation needed]}

Additionally, low levels of GABA, a neurotransmitter that reduces activity in the central nervous system, contribute to anxiety. A number of anxiolytics achieve their effect by modulating the GABA receptors.^[12][13][14]

Selective serotonin reuptake inhibitors, the drugs most commonly used to treat depression, are also frequently considered as a first line treatment for anxiety disorders.^[15] A recent study using functional brain imaging techniques suggests that the effects of SSRIs in alleviating anxiety may result from a direct action on GABA neurons rather than as a secondary consequence of mood improvement.^[16]

Severe anxiety and depression are commonly induced by sustained alcohol abuse which in most cases abates with prolonged abstinence. Even moderate, sustained alcohol use may increase anxiety and depression levels in some individuals.^[17] Caffeine, alcohol and benzodiazepines can worsen or cause anxiety and panic attacks.^[18] In one study in 1988–1990,^[19] illness in approximately half of patients attending mental health services at one British hospital psychiatric clinic, for conditions including anxiety disorders such as panic disorder or social phobia, was determined to be the result of alcohol or benzodiazepine dependence. In these patients, cessation of their anxiety symptoms corresponded with stopping the use of the benzodiazepine or alcohol.

Intoxication from stimulants is likely to be associated with repetitive panic attacks.^{[citation needed]}

There is evidence that chronic exposure to organic solvents in the work environment can be associated with anxiety disorders. Painting, varnishing and carpet laying are some of the jobs in which significant exposure to organic solvents may occur.^[20]

Later in life, anxiety disorder can arise in response to life stresses such as financial worries or chronic physical illness. Somewhere between 4% and 10% of older adults are diagnosed with anxiety disorder, a figure which is probably an underestimate due to the tendency of adults to minimize psychiatric problems or to focus on their physical manifestations. Anxiety is also common among older people who have dementia. On the other hand, anxiety disorder is sometimes misdiagnosed among older adults when doctors misinterpret symptoms of a physical ailment (for instance, racing heartbeat due to cardiac arrhythmia) as signs of anxiety.^[21]

Types

Generalized anxiety disorder

Generalized anxiety disorder is a common chronic disorder characterized by long-lasting anxiety that is not focused on any one object or situation. Those suffering from generalized anxiety experience non-specific persistent fear and worry and become overly concerned with everyday matters.^[22] Generalized anxiety disorder is the most common anxiety disorder to affect older adults.^[21]

Panic disorder

In panic disorder, a person suffers from brief attacks of intense terror and apprehension, often marked by trembling, shaking, confusion, dizziness, nausea, difficulty breathing. These panic attacks, defined by the APA as fear or discomfort that abruptly arises and peaks in less than ten minutes, can last for several hours and can be triggered by stress, fear, or even exercise; although the specific cause is not always apparent.

In addition to recurrent unexpected panic attacks, a diagnosis of panic disorder also requires that said attacks have chronic consequences: either worry over the attacks' potential implications, persistent fear of future attacks, or significant changes in behavior related to the attacks. Accordingly, those suffering from panic disorder experience symptoms even outside of specific panic episodes. Often, normal changes in heartbeat are noticed by a panic sufferer, leading them to think something is wrong with their heart or they are about to have another panic attack. In some cases, a heightened awareness (hypervigilance) of body functioning occurs during panic attacks, wherein any perceived physiological change is interpreted as a possible life threatening illness (i.e. extreme hypochondriasis) .

Phobias

The single largest category of anxiety disorders is that of Phobia, which includes all cases in which fear and anxiety is triggered by a specific stimulus or situation. Sufferers typically anticipate terrifying consequences from encountering the object of their fear, which can be anything from an animal to a location to a bodily fluid.

Agoraphobia

Agoraphobia is the specific anxiety about being in a place or situation where escape is difficult or embarrassing.^[23] Agoraphobia is strongly linked with panic disorder and is often precipitated by the fear of having a panic attack. A common manifestation involves needing to be in constant view of a door or other escape route. In addition to the fears themselves, the term agoraphobia is often used to refer to avoidance behaviors that sufferers often develop. For example, following a panic attack while driving, someone suffering from agoraphobia may develop anxiety over driving and will therefore avoid driving in the future. These avoidance behaviors can often have serious consequences; in severe cases, one can even be confined to one's home.

Social anxiety disorder

Social anxiety disorder (also known as social phobia) describes an intense fear of negative public scrutiny or of public embarrassment or humiliation. This fear can be specific to particular social situations (such as public speaking) or, more typically, is experienced in most (or all) social interactions. Social anxiety often manifests specific physical symptoms, including blushing, sweating, and difficulty speaking. Like with all phobic disorders, those suffering from social anxiety will attempt to avoid the source of their anxiety; in the case of social anxiety this is particularly problematic, and in severe cases can lead to complete social isolation.

Obsessive-compulsive disorder

Obsessive compulsive disorder is a type of anxiety disorder primarily characterized by repetitive obsessions (distressing, persistent, and intrusive thoughts or images) and compulsions (urges to perform specific acts or rituals). The OCD thought pattern may be likened to superstitions insofar as it involves a belief in a causative relationship where, in reality, one does not exist. Often the process is entirely illogical; for example, the compulsion of walking in a certain pattern may be employed to alleviate the obsession of impending harm. And in many cases, the compulsion is entirely inexplicable, simply an urge to complete a ritual triggered by nervousness.

In a minority of cases, sufferers of OCD may only experience obsessions, with no overt compulsions; a much smaller number of sufferers experience only compulsions.^[24]

Post-traumatic stress disorder

Post-traumatic stress disorder or PTSD is an anxiety disorder which results from a traumatic experience. Post-traumatic stress can result from an extreme situation, such as combat, rape, hostage situations, or even serious accident. It can also result from long term (chronic) exposure to a severe stressor,^[25] for example soldiers who endure individual battles but cannot cope with continuous combat. Common symptoms include flashbacks, avoidant behaviors, and depression.^[24]

Separation anxiety

Separation anxiety disorder is the feeling of excessive and inappropriate levels of anxiety over being separated from a person or place. Separation anxiety itself is a normal part of development in babies or children, and it is only when this feeling is excessive or inappropriate that it can be considered a disorder.^[26] Separation anxiety disorder affects roughly 7% of adults and 4% of children, but the childhood cases tend to be more severe, in some instances even a brief separation can produce panic.^[27][28]

Treatment

Treatment options available include lifestyle changes; psychotherapy, especially cognitive behavioral therapy; and pharmaceutical therapy. Education, reassurance and some form of cognitive-behavioral therapy should almost always be used in treatment.^{[citation needed]}

When medication is indicated SSRIs, such as fluoxetine (Prozac), sertraline (Zoloft), paroxetine (Paxil) and escitalopram (Lexapro) are generally recommended as first line agents. SNRIs such as venlafaxine (Effexor) are also effective. Benzodiazepines, such as alprazolam (Xanax), clonazepam (Klonopin) and diazepam (Valium) are also sometimes indicated for short-term or PRN use. They are usually considered as a second line treatment due to disadvantages such as cognitive impairment and due to their risks of dependence and withdrawal problems.^[29] Other medications commonly prescribed for anxiety disorders include GABA analogues such as gabapentin (Neurontin) or pregabalin (Lyrica), MAOIs such as phenelzine (Nardil) or tranylcypromine (Parnate), as well as the novel antidepressant mirtazapine (Remeron). TCAs such as imipramine, as well as atypical antipsychotics such as quetiapine, and piperazines such as hydroxyzine are also occasionally prescribed.^[30]

These medications need to be used with extreme care among older adults, who are more likely to suffer side effects because of coexisting physical disorders. Adherence problems are more likely among elderly patients, who may have difficulty understanding, seeing, or remembering instructions.^[21]

Treatment controversy arises because while some studies indicate that a combination of medication and psychotherapy can be more effective than either one alone; others suggest pharmacological interventions are largely palliative, and can actually interfere with the mechanisms of successful therapy.^[31] Meta-analysis indicates that psychotherapeutic interventions have superior long-term efficacy when compared to pharmacotherapy.^[32] However, the right treatment may very much depend on the individual patient's genetics and environmental factors.

Regular aerobic exercise, improving sleep hygiene and reducing caffeine are often useful in treating anxiety.

See also

• Antidepressant
• Anxiolytic
• Benzodiazepine
• Cognitive behavioral therapy
• Somatosensory amplification
• Psychologist
• Psychotherapy

Further reading

• Khouzam, HR (March 2009). "Anxiety Disorders: Guidelines for Effective Primary Care. Part 1: Diagnosis". Consultant 49 (3). http://www.consultantlive.com/display/article/10162/1387611. 
• Khouzam, HR (April 2009). "Anxiety Disorders: Guidelines for Effective Primary Care. Part 2: Treatment". Consultant 49 (4). http://www.consultantlive.com/display/article/10162/1399819. 
• Vanin, John; Helsley, James (2007). Anxiety Disorders: A Pocket Guide For Primary Care. Humana Press. ISBN 978-1-58829-923-9. 
• Michelle G. Craske (2003), Origins of Phobias and Anxiety Disorders: Why More Women than Men?, Pergamon Publisher, ISBN 978-0080440323 [1]
• Schutz, Samantha (2006). I Don't Want to Be Crazy: A Memoir of Anxiety Disorder. PUSH. ISBN 978-0-4398-0518-6. 

References

External links

• Anxiety Disorders Association of America Information for families, clinicians and researchers