Understanding Anxiety: A Shock and Startle Test with Xanax and Lyrica

Making a diagnosis of generalized anxiety is sometime a tricky proposition. Anxiety has many manifestations as well as many underlying causes. Anxiety may be chronic and always at the edge of a person’s consciousness or the condition may flare up in acute episodes called panic attacks. Appropriate treatment is essential and typically involves a mix of cognitive-behavioral therapy, pharmaceuticals, and careful follow-up by the treating physician. Xanax (alprazolam) is currently one of the preferred medications for dealing with many anxiety-related psychological illnesses. Anxiety should not be ignored, as the effects of nervous tension and fear include a decrease in quality of life, along with possible secondary effects such as high blood pressure.

Researchers in the Netherlands recently tested a model for understanding the nature of anxiety in humans. At the same time, the experiment highlighted the effectiveness of certain medications at reducing some aspects of anxiety. Specifically, these researchers used the startling effects of white noise and electric shocks to induce surprise or fear in the subjects. In addition to Xanax, subjects were given Lyrica (pregabalin), diphenhydramine (a common sedative ingredient in over-the-counter cold remedies), or placebo. Individual anxiety levels were measured through subjective reporting and a number of objective tests, including eye movements, pupil dilation, and skin conductance. The design of the experiment included random shocks and noises, both with and without prior warning.

As expected, shocking events preceded by a warning produced less anxiety than those that came by surprise. Both Xanax and diphenhydramine reduced overall levels of anxiety but for very different reasons. Whereas Xanax works by altering certain neurotransmitter levels, diphenhydramine has a more general, systemic effect. Surprisingly, subjects given Lyrica showed very little modulation of their anxiety levels. Researchers surmised that because Lyrica takes longer (up to 6 hours) to reach peak effectiveness, the experiment wasn’t capturing an accurate picture of events.

This experiment confirmed that Xanax is effective at reducing one manifestation of anxiety: the so-called “fear-potentiated startle response.” However, the results were less informative about anxiety in general than the researchers had hoped. The sample size was too small to uncover any new revelations about the nature of human anxiety. Ideally, research will one day make the work of quickly and accurately diagnosing anxiety disorders much easier and more straightforward.

References
Baas, J., Mol, N., Kenemans, J. L., Prinssen, E. P., Niklson, I., Xia-Chen, C., et al. (2009). Validating a human model for anxiety using startle potentiated by cue and context: the effects of alprazolam, pregabalin and diphenhydramine. Psychopharmacology, 205, 73-84.

The preceding article was solely written by the author named above. Any views and opinions expressed are not necessarily shared by GoodTherapy.org. Questions or concerns about the preceding article can be directed to the author or posted as a comment below.