Therapeutic Strategies for Treatment of Inflammation-related Depression.

BACKGROUND: Mounting evidence demonstrates enhanced systemic levels of inflammatory mediators in depression, indicating that inflammation may play a role in the etiology and course of mood disorders. Indeed, proinflammatory cytokines induce a behavioral state of conservation- withdrawal resembling human depression, characterized by negative mood, fatigue, anhedonia, psychomotor retardation, loss of appetite, and cognitive deficits. Neuroinflammation also contributes to non-responsiveness to current antidepressant (AD) therapies. Namely, response to conventional AD medications is associated with a decrease in inflammatory biomarkers, whereas resistance to treatment is accompanied by increased inflammation. METHODS: In this review, we will discuss the utility and shortcomings of pharmacologic AD treatment strategies focused on inflammatory pathways, applied alone or as an adjuvant component to current AD therapies. RESULTS: Mechanisms of cytokine actions on behavior involve activation of inflammatory pathways in the brain, resulting in changes of neurotransmitter metabolism, neuroendocrine function, and neuronal plasticity. Selective serotonin reuptake inhibitors exhibit the most beneficial effects in restraining the inflammation markers in depression. Different anti-inflammatory agents exhibit AD effects via modulating neurotransmitter systems, neuroplasticity markers and glucocorticoid receptor signaling. Anti-inflammatory add-on therapy in depression highlights such treatment as a candidate for enhancement strategy in patients with moderate-to-severe depression. CONCLUSION: The interactions between the immune system and CNS are not only involved in shaping behavior, but also in responding to therapeutics. Even though, substantial evidence from animal and human research support a beneficial effect of anti-inflammatory add-on therapy in depression, further research with special attention on safety, particularly during prolonged periods of antiinflammatory co-treatments, is required.

Improving Current Treatments for Schizophrenia.

Preclinical Research After the identification of the schizophrenia as an illness over a century ago, treatment of affected individuals included unspecific, mostly very robust methods including deep insulin coma and lobectomy/leucotomy. The first relatively specific treatment of schizophrenia started about 60 years ago with the antipsychotic chlorpromazine. All currently approved antipsychotic drugs block dopamine receptors, indicating that manipulation of dopaminergic function is fundamental to a therapeutic response in psychosis. Despite refinements in their mechanism of action, the therapeutic effects of subsequent generations of antipsychotics are insufficient in claiming superiority over the first generation, with the possible exception of clozapine. Dopamine receptor blockade is necessary but not always sufficient for antipsychotic response and improvements have been reported with molecules acting on other receptors (glutamate, glycine, cannabidiol, estrogen), intracellular signaling proteins, or products of identified risk genes. Here, we review the current status of drugs under investigation. In addition, we emphasize that the development of the novel compounds to target the underlying cognitive dysfunction and negative symptom dimension of full blown schizophrenia, or attenuated psychosis syndrome and specific endophenotypes related to the increased risk of psychosis in the general population, alongside efforts to deconstruct the concept of schizophrenia(s), represent the best way to meet patient needs for better therapies and more favorable outcomes. Drug Dev Res 77 : 357-367, 2016. © 2016 Wiley Periodicals, Inc.

Modulation of c-Jun N-terminal kinase signaling and specific glucocorticoid receptor phosphorylation in the treatment of major depression.

Glucocorticoid resistance is a common finding in major depressive disorder. Increased glucocorticoid receptor (GR) phosphorylation at serine 226 is associated with increased glucocorticoid resistance. Previously we have demonstrated that depressed patients exhibit higher levels of GR phosphorylated at serine 226 compared to healthy controls. The enzyme that is involved in this specific GR phosphorylation is c-Jun N-terminal kinase (JNK). We propose that modulation of glucocorticoid phosphorylation at serine 226, by targeting JNK signaling pathway, could be a potential strategy for antidepressant treatment. We base this assumption on the results of previous research that examined GR phosphorylation and JNK signaling in animal models and human studies. We also discuss the potential challenges in targeting JNK signaling pathway in depression.