Biological mechanisms of depression following treatment with interferon for chronic hepatitis C: A critical systematic review.

BACKGROUND: A significant subset of patients infected by the hepatitis C virus (HCV) develops a major depressive episode (MDE) during Interferon-alpha (IFN-α) based immunotherapy. We performed a systematic review of studies which examined biological mechanisms contributing to the onset of a MDE during IFN-α-based immunotherapy for HCV. METHODS: Major electronic databases were searched from inception up until 15th February 2016 for peer-reviewed prospective studies that had enrolled HCV infected patients who received IFN-α treatment. A diagnosis of MDE had to be established by means of a standardized diagnostic interview at baseline and endpoint. RESULTS: Eight unique references met inclusion criteria. A total of 826 participants with HCV (37.3% females, mean age 46.7 years) were included in this systematic review. The overall MDE incidence rate was 34.8%, with follow-up ranging between 4 and 48 weeks. The methodological quality varied across selected studies. It was observed that Interleukin-6, salivary cortisol, arachidonic acid / eicosapentaenoicacid plus docosahexaenoic acid ratio, and genetic polymorphisms may present variations which are linked to a predisposition to INF-α-induced depression. LIMITATIONS: A meta-analysis could not be performed due to the diverse biological mechanisms investigated and the lack of replicated evidence. CONCLUSIONS: This systematic review indicates that several potential mechanisms may be implicated in the onset of a MDE following IFN-α-based immunotherapy for chronic HCV. However, replicated evidence is lacking and therefore the mechanisms involved in IFN-α-induced depression in humans remain unclear.

Cognitive remission: a novel objective for the treatment of major depression?

BACKGROUND: Cognitive dysfunction in major depressive disorder (MDD) encompasses several domains, including but not limited to executive function, verbal memory, and attention. Furthermore, cognitive dysfunction is a frequent residual manifestation in depression and may persist during the remitted phase. Cognitive deficits may also impede functional recovery, including workforce performance, in patients with MDD. The overarching aims of this opinion article are to critically evaluate the effects of available antidepressants as well as novel therapeutic targets on neurocognitive dysfunction in MDD. DISCUSSION: Conventional antidepressant drugs mitigate cognitive dysfunction in some people with MDD. However, a significant proportion of MDD patients continue to experience significant cognitive impairment. Two multicenter randomized controlled trials (RCTs) reported that vortioxetine, a multimodal antidepressant, has significant precognitive effects in MDD unrelated to mood improvement. Lisdexamfetamine dimesylate was shown to alleviate executive dysfunction in an RCT of adults after full or partial remission of MDD. Preliminary evidence also indicates that erythropoietin may alleviate cognitive dysfunction in MDD. Several other novel agents may be repurposed as cognitive enhancers for MDD treatment, including minocycline, insulin, antidiabetic agents, angiotensin-converting enzyme inhibitors, S-adenosyl methionine, acetyl-L-carnitine, alpha lipoic acid, omega-3 fatty acids, melatonin, modafinil, galantamine, scopolamine, N-acetylcysteine, curcumin, statins, and coenzyme Q10. The management of cognitive dysfunction remains an unmet need in the treatment of MDD. However, it is hoped that the development of novel therapeutic targets will contribute to 'cognitive remission', which may aid functional recovery in MDD.