Hepatitis C virus and depression in drug users

Clinical case studies have implicated depression as a possible side-effect of interferon treatment for the Hepatitis C virus (HCV). However, because these studies generally did not include a pretreatment assessment of depression, it cannot be definitively stated whether depression is a side-effect of interferon treatment, a syndrome coexisting with HCV, or a common characteristic of individuals who are vulnerable to HCV infection. To gather more information about this issue, self-reported depressive symptomatology of drug users with HCV who have not received interferon treatment was compared to that of uninfected drug users.

Subjects were 309 drug users not currently in substance abuse treatment who were participating in a National Institute on Drug Abuse project. Subjects completed the Center for Epidemiological Studies-Depression (CES-D) instrument and provided a blood sample for HCV testing.

Serological findings revealed that 52.4% of the subjects tested positive for HCV antibodies. Of the HCV-positive subjects, 57.2% had significant depressive symptomatology, whereas only 48.2% of the HCV-negative subjects did, for an overall rate of 52.6%. The two groups also differed on two specific dimensions of depression, with the HCV-positive group scoring lower on the Positive Affect scale and higher on the Somatic/Retarded Activity scale.

These findings reveal high levels of depressive symptomatology among drug users, as well as the possibility of a coexisting depressive syndrome with HCV infection. These findings raise the possibility that depression associated with interferon treatment may, at least partially, be accounted for by preexisting depression. Further research is needed to determine the nature and origins of depression in individuals in treatment with interferon for HCV with specific focus placed on determining the dimensions of depression associated with HCV infection and interferon treatment.