Depression is rapidly becoming the leading cause of disease burden (negative effects on quality of life) in the world. Psychologists and biologists have been trying to understand the underlying mechanisms of depression for a long time, wondering whether it is mainly biological or psychological in nature; a disease of the body or of the mind? My clinical experience is that it can be either or both, which is why a thorough assessment is essential. For some people the roots of their depression lie in difficult early circumstances, abusive relationships or a traumatic event. For others there may be a genetic predisposition to the illness, it ‘runs in the family’, or some other physiological factor.

Several studies have demonstrated a relationship between inflammation in the body and depression. Inflammation is your body’s response to illness or infection and can be activated by a number of factors such as poor diet, underlying illness and chronic stress. Many studies have illustrated that the higher the degree of inflammation in the body the more severe the depressive symptoms and vice versa. The consistency of this finding has led to the ‘Inflammatory Hypothesis of Depression’, proposing that inflammation is the driving force in depression in many people, and that it can increase symptom severity in those already dealing with low mood.

In a trial thought to be the first of its kind researchers from Brazil and the USA looked at the levels of inflammation in patients' blood as well as the severity of their depression before and after 16 standard (50 minutes) sessions of psychotherapy (plus an extra two for data collection). The result demonstrated a relationship between the levels of markers for inflammation and the severity of symptoms such that after psychotherapy treatment patients were less depressed and their inflammation had reduced. Previous research had looked at the ways that medication and CBT could reduce inflammation but this was the first study to look at the role of psychodynamic psychotherapy and the results are interesting enough to warrant further research.

The implications are powerful because, as the upward trend of depression continues, it will become increasingly important to find effective and low-cost treatments for the illness. This study suggests that patients could potentially gain relief from their mild or moderate depression in as little as four months and without the side-effects associated with medication.

Silva, G. D. G. d., Wiener, C. D., Barbosa, L. B., Araujo, J. M. G., Molina, M. L., Martin, P. S., Oses, J. P., Jansen, K., Souza, L. D. d. M. & Silva, R. A. d. (2016). Pro-inflammatory cytokines and psychotherapy in depression: Results from a randomised clinical trial. Journal of Psychiatric Research, 75, 57-64.