Anxiety disorders are among the most prevalent of psychiatric disorders, yet they often go untreated or unrecognized. Anxiety disorders can be crippling, leading to under- or unemployment, inhibition in social relationships, and enormous morbidity. Anxiety in itself is clearly adaptive, but an excessive anxiety response, which clearly has a biological underpinning, impairs performance and functioning.
Anxiety disorders are heterogeneous, tend to respond to antidepressant medication, particularly those which are most serotonergic, such as selective serotonin reuptake inhibitors, and tend to be diagnosed much more often in women than in men.
Acute Stress Disorder
Selective Serotonin Reuptake Inhibitors (SSRI's)
Monoamine Oxidase Inhibitors (MAOI's)
Acute Stress Disorder:
Essentially a "traumatic event" in which the person witnessed or experienced actual or threatened "death or serious injury" and the "person's response involved intense fear, helplessness, or horror" leads to the following symptoms:
Course: minimum of 2 days, maximum of 4 weeks, all occurring within 4 weeks of the traumatic event.
Source: DSM-IV (summarized and condensed)
After 4 weeks, a diagnosis of Posttraumatic Stress Disorder should be given.
A panic attack is not merely a bout of anxiety. Rather it is an overwhelming discrete period of intense fear or discomfort with an abrupt onset peaking within 10 minutes in which the person usually has the sensation that they are going to die. Many patients with panic attacks do not realize they are having one; instead, they think they are suffocating or having a heart attack. To have a panic attack, someone must experience 4 or more of the following within a 10 minute period:
Recurrent, unexpected panic attacks followed by at least 1 month of persistent concern about having additional attacks or worry about the implications of having the attack (e.g., losing control, having a heart attack, or going crazy), with a significant change in behavior related to the attacks (e.g., avoiding the grocery store in which the person had the attack).
Panic disorder occurs with or without agoraphobia, which is essentially fear of going out in public.
Commonly mistaken for shyness, social phobia is a true disorder that consists of a crippling fear of being embarrassed in a public setting. It can present as severe "stage fright" but can be so severe that a person is unable to eat in public. Social phobia responds well to cognitive-behavioral therapy, benzodiazepines, and antidepressant medications, particularly SSRI's.
Although the results of controlled studies are disappointing, many practitioners will prescribe beta blockers for performing artists who have a mild variant of social phobia, namely a fear of public performance. The beta blockers can be sedating and inhibit the physiological stigmata of anxiety (e.g., tachycardia and tremor) but tend not to lyse the actual anxiety.
The treatment of anxiety disorders can include:
Selective serotonin reuptake inhibitors (SSRI's) work via blocking the serotonin transporter which normally transports serotonin from the synaptic cleft back into the neuron. By blocking this, the SSRI's lead to a buildup of serotonin (5-HT) in the synaptic cleft. However, although this effect is almost immediate after taking the medication, the therapeutic effects are not seen clinically until 2-6 weeks after beginning treatment, so the ultimate mechanism of action maybe more complicated than this. Stopping an SSRI suddenly may lead to a flu-like syndrome with tearfulness, anergia, and general malaise. Resumption of the former dose and a gradual tapering will avoid this.
The most notorious side effects of SSRI's are sexual, mainly anorgasmia and ejaculatory delay, but also blunted sexual desire and in some cases erectile dysfunction. They also can cause GI side effects, namely nausea and diarrhea. In anxious patients, this can be very problematic, since they will likely experience side effects before therapeutic benefits, and may become convinced that the medication is causing serious harm. It is a good idea to reassure them beforehand and guide them through the initial period. Other side effects include jitteriness or worsened anxiety, although this is less common than folklore holds. Sleep profiles actually improve about as rapidly as they do with older sedating agents such as tricyclics, so don't choose an older agent ONLY because a patient has insomnia.
Tricyclic antidepressants used to be the bane of every medical student's existence, since we had to memorize tables listing their side effect profiles. In general, tricyclics affect three major neurotransmitters:
Tricyclics are lethal in overdose (mechanism: complete heart block), so tend to be avoided in the actively suicidal patient, but are nevertheless very useful medication. None is more efficacious than the others, nor are they less efficacious than the newer agents such as fluoxetine, an SSRI, but because of their side effect profile and potential for lethality, they tend to be used less frequently.
Monoamine oxidase inhibitors are antidepressants that also maybe helpful in anxiety disorders. However, because of the severe dietary restrictions (patients must avoid any food containing tyramine, meaning many cheeses, wines, and other foods are off limits) as well as potentially lethal medication interactions (pseudophedrine can be lethal), MAOI's, as they are known, tend not to be prescribed much. They are excellent medications in some patients who respond to nothing else.
Benzodiazepines work via the GABA (gamma-aminobutyric acid) receptor. Benzodiazepines, although excellent medications acutely for the anxious patient, may cause tolerance, sedation, and memory impairment. After chronic use, abrupt cessation may lead to a severe withdrawal. Benzodiazepines increase the sedation and motor impairment of alcohol, and are the most common prescribed medication to cause motor vehicle accidents. For these reasons, in most cases, antidepressants are preferable as first line anxiolytics (anti-anxiety agents).