In a very strange and astounding research, scientists have found that more and more numbers of young people are feeling depressed as modern world is getting clean. Using the information from the laboratory and human studies, researchers has explored the idea that there may be a relationship between depression and some kind of bacteria.

This study was carried out by researchers from Emory University School of Medicine, Atlanta, the University of Colorado and University College London. It was published in the peer-reviewed medical journal Archives of General Psychiatry.

Researchers argue that the improvements to hygiene that have reduced the risk of infectious disease may also have disrupted evolutionary relationships with micro-organisms that may have a beneficial influence on health, including mental health. The study was aimed to investigate whether the reduction in levels of certain micro-organisms in our food, soil and the gut, is contributing to any increasing prevalence of depression.

The authors identified a range of previous studies on the topic of inflammation, stress and depression. These ranged from laboratory studies in cells and animals, to long-term studies that had examined human health for a number of years. In this, researchers did not present any figures that summarise the collective data. The emphasis of this study was a narrative discussion of the current evidence and the generation of theories relating to the potential role of micro-organisms in the development of depression. The authors go on to suggest that certain micro-organisms might be useful in reducing depressive symptoms in affected people in industrialised countries.

This was an extensive overview of the potential role of inflammation and the immune system in the development of depression. The paper puts forward several arguments, which are mainly speculative and it is not possible to draw firm conclusions without further evidence to support the many biological mechanisms proposed. A causal relationship cannot be established without looking at individual people and their exposure to environmental risk factors and development of depression.

Depression and related mental health illnesses have complex causes, which will vary between individuals. Risk factors can include genetics, medical health, and environmental, social and life circumstances. However, development and testing of new hypotheses is vital to scientific progress.