text: ***4.2.3 Examples of specific prevalence estimates***
  The methodologies to estimate the burden of diseases have been developed over the past 30 years. In 
  the coming years we can expect that**research will contribute to more precise estimates**of the work- 
  related share of the burden of the diseases. 
  
  Very probably**mental health and biological agents will be fully incorporated in such estimates**, 
  and research will contribute to better explanations, for example, of the work-related prevalence of MSDs. 
  Two groups of diseases examples —**mental health**and**musculoskeletal diseases**— are briefly 
  presented in this chapter. 
  
  The first**‘Global Burden of Disease’ study**(1996, the study was the breakthrough for the concept of 
  DALYs) is quite astonishing. Already then, the authors complained that the*‘burden of psychiatric*
  *conditions has been heavily underestimated*’. In their estimation of the globally leading causes of 
  disability they put four psychiatric conditions under the first 10: 
  
  • Unipolar major depression – 10.7% (of all causes) 
  • Bipolar disorders – 3.0% (of all causes) 
  • Schizophrenia – 2.6% (of all causes) 
  • Obsessive-compulsive disorders – 2.2% (of all causes) 