Infliximab and its rapidly emerging role in the management of psychiatric disorders

To the Editor

I read with great interest the recent article by Austin and Tan (2012). Interestingly, infliximab is rapidly emerging as a major therapeutic option for the treatment of other psychiatric disorders, especially recalcitrant psychiatric disorders.

Infliximab attenuates depressive symptoms in patients with elevated baseline inflammatory markers. In depressed patients who respond to infliximab therapy, the baseline tumour necrosis factor (TNF)-alpha concentration is much higher than in those who do not respond to intravenous infliximab therapy (Raison et al., 2012). In particular, steroid-induced depression especially shows a good response to infliximab therapy. Infliximab is especially potent in reducing and mitigating depressive symptoms in patients with rheumatoid disorders such as ankolysing spondylitis, as well as skin disorders such as psoriasis (Ertenli et al., 2012). There is a significant decline in the Beck Depression Inventory scores even after the first intravenous dose of infliximab itself. A significant decline in high-sensitivity C-reactive protein is seen in depressed patients who responded to intravenous therapy with infliximab. Similarly, patients with Crohn’s disease who are administered infliximab show significant improvements in the social as well as the emotional dimensions of the Inflammatory Bowel Disease Questionnaire.

Infliximab also improves symptoms in patients with anxiety. For instance, Ertenli et al. (2012) in a recent study have reported a significant reduction in the Hospital Anxiety and Depression Scale anxiety scores following infliximab infusions. A simultaneous improvement in quality of life is seen. Similarly, infliximab infusions significantly improve fatigue especially in cancer patients. Patients with bipolar disorder typically demonstrate higher TNF-alpha levels. Hence, TNF-alpha antagonism may have a significant affect in ameliorating the symptoms of bipolar disorder. These results have been corroborated in recent case reports by Bassukas et al. (2008). Similarly, elevated TNF-alpha and reduced interleukin 4 levels are seen in schizophrenic patients during psychotic exacerbations. Infliximab may very well play a major role on attenuating TNF-alpha levels and resolving these exacerbations. In fact, Reimer et al. (2009) have reported a patient with Crohn’s disease and coexisting psychosis. They have reported the successful treatment of the psychotic manifestations in this patient with infliximab.

As is clear from the above, there is good evidence that infliximab is of benefit in psychiatric illness associated with inflammation. There is a plausible theoretical basis for its clinical application in other psychiatric illnesses, given the demonstration of increased inflammatory markers in these populations. The above examples clearly illustrate the important role that infliximab may have to play in the management of psychiatric disorders.