Anxiety is distressing. According to Ronald M. Doctor and colleagues in their book "The Encyclopedia of Phobias, Fears and Anxieties," "Anxiety is an unpleasant feeling of generalized fear and apprehension, often of unknown origin, accompanied by physiological symptoms." With anxiety, the heartbeat speeds, muscles tighten, and the individual may perspire profusely. Sleep becomes elusive.
Feelings of anxiety may be triggered by some medicines. An excessive amount of caffeine can generate anxiety in some individuals, as can some antidepressants and most stimulants. In addition, some herbal supplements may trigger anxiety, according to the National Center for Complementary and Alternative Medicine.
Suddenly stopping a drug a person has been taking for a while can induce anxiety, as with some antidepressants say Elias A. Khawam, M.D. and colleagues in their article for Cleveland Clinic Journal of Medicine.
Caffeine
Many experts consider caffeine a drug. According to the Johns Hopkins Bayview site, caffeine is "the most commonly used mood-altering drug in the world." The "Diagnostic and Statistical Manual of the American Psychiatric Association" includes caffeine-induced anxiety disorder as a diagnosis under the category of caffeine-related disorders.
Caffeine is included as an ingredient in many medications and, according to the Johns Hopkins article, analgesics may contain up to 65 mg of caffeine. Excessive caffeine consumption--more than 1,000 mg of caffeine daily--can lead to anxiety, according to the International Food Information Council Foundation in their report on caffeine. The report also notes, however, that the American Psychiatric Association acknowledges that some people are very sensitive to caffeine and may experience caffeine intoxication, with symptoms of nervousness, restlessness, and insomnia at consumption greater than 250 mg per day.
Antidepressants
Khawam and colleagues note selective serotonin reuptake inhibitors--SSRIs--may cause anxiety as well as nightmares and insomnia. Increased anxiety, if it occurs, is more common at the onset of treatment with SSRIs, say the doctors.
Stopping an antidepressant abruptly may trigger anxiety, say Khawam and colleagues, especially with extended-release venlafaxine--Effexor XR. Khawam and colleagues recommend that this drug be slowly tapered over days or weeks.
Duloxetine--Cymbalta--is another antidepressant which may cause initial anxiety as well as insomnia, irritability and restlessness, according to Khawam and colleagues. Duloxetine may also cause anxiety with abrupt cessation, and thus should be tapered slowly.
Herbal Supplements
Some herbal supplements can cause anxiety, such as ephedra, a formerly popular herb. The FDA banned ephedra as a supplement in the United States in 2004, as well as any supplement containing ephedra. This ban was challenged in court but has been upheld. However, some companies have continued to sell the drug, according to the National Center for Complementary and Alternative Medicine.
Yohimbe is another drug that can induce anxiety, according to the NCCAM. It is an herb derived from the bark of a western African tree which purportedly improves male sexual response--although no clinical studies have been performed with this drug, according to the NCCAM. THe NCCAM says yohimbe can cause anxiety, elevated heart rate, dizziness and sleeplessness.
Scheduled Stimulants
Individuals taking stimulants such as amphetamines may develop anxiety, especially if the drug is not prescribed properly--or the drug is not prescribed at all, as in the case of abuse. Stimulants such as amphetamines are controlled by the federal Drug Enforcement Administration because of their abuse potential.
Some individuals abuse amphetamine-like substances such as methylphenidate--Ritalin--and may buy amphetamines from others diagnosed with attention-deficit/hyperactivity disorder--ADHD. Stimulants are commonly prescribed for ADHD.
According to the Center for Substance Abuse Research at the University of Maryland, up to 35 percent of college students misuse stimulants, especially at high stress times such as final exams. They may develop symptoms of anxiety as a result of this abuse.
References
- "Cleveland Clinic Journal of Medicine"; Side Effects of Antidepressants: An Overview; Elias A. Khawam, M,D., Georgia Laurencic, M.D. and Donald A. Malone, Jr, M.D.; April 2006
- National Center for Complementary and Alternative Medicine: Herbs at a Glance: Yohimbe
- International Food Information Council Foundation: Caffeine & Health: Clarifying the Controversies
- Johns Hopkins Bayview Medical Center: Information about Caffeine Dependence
- "Diagnostic and Statistical Manual of Mental Disorders: Fourth Edition Text Revision. DSM-IV-TR"; American Psychiatric Association; 2000
