Multiple Sclerosis Home > Avonex and Depression
In clinical studies where side effects were reported with Avonex, depression appeared to be a possible side effect. Since depression is common among people with multiple sclerosis, however, it is not known whether it is actually related to the medication. If you are taking Avonex and depression occurs, be sure to contact your healthcare provider.
Avonex® (interferon beta-1a) is a prescription medication used in the treatment of multiple sclerosis (MS). According to data from clinical trials, depression may be a possible Avonex side effect. In fact, depression seems to be a side effect of many interferon medications.
Clinical trials are designed to factor out many possible variables in order to measure the effectiveness and side effects of medications. During a study, some people are given the actual medication, while others are given a placebo (which looks like the actual medication but does not contain any of the active ingredients). In most studies, the people (and sometimes the healthcare providers) are "blinded," which means that they do not know if they are taking the real medication or the placebo.
Side effects occur in people who are taking the medicine and in people who are taking a placebo. By studying both groups, it becomes easier to tell which side effects are definitely drug related, which may be drug related, and which have nothing to do with the drug. In clinical studies, up to 18 percent of people taking Avonex reported having depression. However, as many as 14 percent of people taking a placebo also reported experiencing depression. Because depression is common among people with multiple sclerosis, it is difficult to tell whether any given case of depression is related to Avonex or not (see Multiple Sclerosis and Depression for more information). However, some factors (such as the timing of the onset of depression in relationship to the medication) may suggest that Avonex may or may not be causing or contributing to a particular case of depression.