Substance-induced anxiety disorder
Prominent anxiety symptoms (i.e., generalized anxiety, panic attacks, obsessive-compulsive symptoms, or phobia symptoms) determined to be caused by the effects of a psychoactive substance is the primary feature of a substance-induced psychotic disorder . A substance may induce psychotic symptoms during intoxication (i.e., while the individual is under the influence of the drug) or during withdrawal (i.e., after an individual stops using the drug).
A substance-induced anxiety disorder is subtyped or categorized based on whether the prominent feature is generalized anxiety, panic attacks, obsessive-compulsive symptoms, or phobia symptoms. In addition, the disorder is subtyped based on whether it began during intoxication on a substance or during withdrawal from a substance. A substance-induced anxiety disorder that begins during substance use can last as long as the drug is used. A substance-induced anxiety disorder that begins during withdrawal may first manifest up to four weeks after an individual stops using the substance.
Causes and symptoms
A substance-induced anxiety disorder, by definition, is directly caused by the effects of drugs—including alcohol, medications, and toxins. Anxiety symptoms can result from intoxication on alcohol, amphetamines (and related substances), caffeine, cannabis (marijuana), cocaine, hallucinogens, inhalants, phencyclidine (PCP) and related substances, and other or unknown substances. Anxiety symptoms can also result from withdrawal from alcohol, sedatives, hypnotics, and anxiolytics, cocaine, and other or unknown substances. Some of the medications which may induce anxiety symptoms include anesthetics and analgesics, sympathomimetics (epinephrine or norepinephrine, for example) or other bronchodilators, anticholinergic agents, anticonvulsants, antihistamines, insulin, thyroid preparations, oral contraceptives, antihypertensive and cardiovascular medications, antiparkinsonian medications, corticosteroids, antidepressant medications, lithium carbonate , and antipsychotic medications. Heavy metals and toxins, such as volatile substances like fuel and paint, organophosphate insecticides, nerve gases, carbon monoxide, and carbon dioxide may also induce anxiety.
The Diagnostic and Statistical Manual of Mental Disorders , ( DSM-IV-TR )—produced by the American Psychiatric Association and used by most mental health professionals in North America and Europe to diagnose mental disorders—notes that a diagnosis is made only when the anxiety symptoms are above and beyond what would be expected during intoxication or withdrawal and when severe. The following list is the criteria necessary for the diagnosis of a substance-induced anxiety disorder as listed in the DSM-IV-TR :
- Prominent anxiety, panic attacks, or obsessions or compulsions.
- Symptoms develop during, or within one month, of intoxication or withdrawal from a substance or medication known to cause anxiety symptoms.
- Symptoms are not actually part of another anxiety disorder (such as generalized anxiety disorder , phobias, panic disorder , or obsessive-compulsive personality disorder ) that is not substance induced. For instance, if the anxiety symptoms began prior to substance or medication use, then another anxiety disorder is likely.
- Symptoms do not occur only during delirium .
- Symptoms cause significant distress or impairment in functioning.
Little is known regarding the demographics of substance-induced anxiety disorders. However, it is clear that they occur more commonly in individuals who abuse alcohol or other drugs.
Diagnosis of a substance-induced anxiety disorder must be differentiated from an anxiety disorder due to a general medical condition. There are some medical conditions (such as hyperthyroidism, hypothyroidism, or hypoglycemia) that can produce anxiety symptoms, and since individuals are likely to be taking medications for these conditions, it can be difficult to determine the cause of the anxiety symptoms. If the symptoms are determined to be due to the medical condition, then a diagnosis of an anxiety disorder due to a general medical condition is warranted. Substance-induced anxiety disorders also need to be distinguished from delirium, dementia , primary psychotic disorders, and substance intoxication and withdrawal.
Clinical history and physical examination are the best methods to help diagnose anxiety disorders in general; however, appropriate laboratory testing will most likely be necessary to specifically identify substance-induced anxiety disorder. Lab tests may include:
- complete blood count (CBC)
- chemistry panels
- serum and/or urine screens for drugs
The underlying cause of the anxiety symptoms, as well as the specific type of symptoms, determine course of treatment and is often similar to treatment for a primary anxiety disorder such as generalized anxiety disorder, phobias, panic disorder, or obsessive-compulsive disorder . Appropriate treatment usually includes medication (antianxiety or antidepressant medication, for example).
Anxiety symptoms induced by substance intoxication usually subside once the substance responsible is eliminated. Symptoms persist depending on the half-life of the substances (i.e., how long it takes the before the substance is no longer present in an individual's system). Symptoms, therefore, can persist for hours, days, or weeks after a substance is last used. Obsessive-compulsive symptoms induced by substances sometimes do not disappear, even although the substance inducing them has been eliminated. More intensive treatment for the obsessive-compulsive symptoms would be necessary and should include a combination of medication and behavioral therapy.
Little is documented regarding the prevention of substance-induced anxiety disorder. However, abstaining from drugs and alcohol, or using these substances only in moderation, would clearly reduce the risk of developing this disorder. In addition, taking medication under the supervision of an appropriately trained physician should reduce the likelihood of a medication-induced anxiety disorder. Finally, reducing one's exposure to toxins and heavy metals would reduce the risk of toxin-induced anxiety disorder.
See also Alcohol and related disorders ; Amphetamines and related disorders ; ; Anxiety and anxiety disorders ; ; Cannabis and related disorders ; Cocaine and related disorders ; Hallucinogens and related disorders ; Inhalants and related disorders ; Phencyclidine and related disorders ; Psychosis ; Sedatives and related disorders ; Substance abuse and related disorders ; Substance-induced psychotic disorder
American Psychiatric Association. Diagnostic and Statistical Manual of Mental Disorders. 4th edition, text revised. Washington, DC: American Psychiatric Association,2000.
Kaplan, Harold I.,M.D., and Benjamin J. Sadock, M.D. Kaplan and Sadock's Synopsis of Psychiatry: Behavioral Sciences, Clinical Psychiatry. 8th edition. Baltimore: Williams and Wilkins.
Jennifer Hahn, Ph.D.