http://health.msn.com/health-topics/...8254>1=31036
Found this article today. Interferon Beta is #8 on their top ten list.
Doesn't specifically say why but I take it has to do with depression and unknown on the long-term use. 1178 Deaths from 1998-2005 on people using Interferon Beta.
Other meds on the list are 2 (other)immune-system modulating drugs, painkillers and antipsychotics.
Sure wish they had more info for this claim.