By guest blogger Tomasz Witkowski
Looking at the latest epidemiological data, it could be argued that we are in the midst of a pandemic of mental illness, of dimensions never before seen in human history. The WHO estimates that over 350 million people around the world are presently suffering from depression, which constitutes almost 5-6 per cent of the population. At its extreme, depression may lead to suicide, by which it is estimated that around 1 million people die every year. And the numbers continue growing. Faced with this rising tide of illness, it is impossible to overestimate the importance of hard facts and data indicating the paths researchers and clinicians may follow in search of ways to help. Sometimes, as suggested by a meta-analysis of 50 years of studies on indicators that help predict suicide attempts, we are entirely helpless. In other cases, like with the recent meta-analysis of the neural correlates of the changes brought about by psychotherapy in depressed brains, study results do bring us hope.
The results of the first systematic review and meta-analysis of biological markers evaluated in randomized trials of psychological treatments for depression in Neuroscience and Biobehavioral Reviews are another attempt at understanding methods of treating this terrifying illness. The authors – Ioana A. Cristea, Eirini Karyotaki, Steven D. Hollon, Pim Cuijpers and Claudio Gentili – quite rightly point out that understanding how psychological interventions impact or are impacted by biological variables has important implications. For many people, their depression co-occurs with a bodily illness, such as cancer, diabetes, heart disease, and immune system and neurological disorders, and at times is a consequence of that illness. Although we still know little about the reciprocal cause-and-effect mechanisms between psychic and somatic symptoms, some studies have suggested that psychological interventions not only change mood, but also normalise the functioning of the autonomic nervous system, with a therapeutic effect on physical conditions, such as heart disease. But is this really true?