Analysis of clinical trials does not show a significant association between depression and beta-interferon (IFNβ) treatment in multiple sclerosis (MS).
MS is considered as a considerable cause of neurological disability in young adults worldwide. While depression is considered a determinant factor of impaired quality of life and poorer prognosis among patients with the condition, it is very often dismissed and undertreated by physicians.
Depression has been related to treatment with some immunomodulatory drugs, such as IFNβ. Data from patients who committed suicide during the pivotal study of interferon used as a disease modifying treatment in MS support this association. There is also lots of evidence of neuropsychiatric toxicity caused by the use of Interferon-alpha (IFNα) as a treatment for other medical conditions.
Although this link still remains relatively unknown, the presence of warnings regarding the possible relationship between depression and IFNβ led to restriction in medical indications some patients.
Experts performed a literature search on MEDLINE and Google Scholar databases, applying PRISMA guidelines for systematic reviews, in a bid to understand the reasons for an increased prevalence in depression in MS and to examine the impact that IFNβ treatment has on mood.
The sampled studies included articles from 1980-2014. Studies were included if the participants were diagnosed with MS and prescribed IFNβ as the main treatment.
Ten studies met full criteria for inclusion and final data extraction. Only three studies support the evidence of a relationship between depression and interferon, which is statistically significant in some patients because depression tends to occur early in the course of treatment. They suggest that only patients on IFNβ treatment with a past history of depression may develop a major depression episode during the first six months.
The remaining articles reviewed suggest the absence of an association.
Researchers concluded that there is not a clear relationship between IFNβ and depression. They said: “A history of depression is a risk factor for developing depression during the first six months of treatment, nevertheless, it is not sufficient to contraindicate it. The development of new strategies is crucial for early detection of depressive symptoms. An adequate treatment can both improve the mood and deal with the neurological disease by increasing treatment adherence and interfering with inflammation.
“Chronic destructive brain changes and serotonergic depletion due to inflammatory factors have been proposed as the underlying cause of depression in these patients. It is suggested that these patients would have fewer functional reserve remaining to deal with stressful life events, which could precipitate a depressive disorder.”