Mental disorders and substance abuse were found to be the two leading causes of nonfatal illness worldwide.
These disorders were responsible for "more of the global burden of deaths and illnesses," than diabetes, tuberculosis, and even HIV/AIDS, Health Day reported.
Opiates were found to be the biggest offender in terms of drug-related health woes.
"Mental and substance use disorders are major contributors to the global burden of disease and their contribution is rising, especially in developing countries. Cost-effective interventions are available for most disorders but adequate financial and human resources are needed to deliver these interventions," study leader Harvey Whiteford, of the Queensland Centre for Medical Health Research at the University of Queensland in Australia, said, according to Health Day.
The findings came from two studies.
The first study analyzed data from 187 countries, the information included 20 mental and substance abuse disorders. The team concluded these root afflictions were responsible for 23 percent of the world's disease burden.
According to medical records, substance abuse is responsible for surprisingly few deaths. The researchers said this is because the fatality is often attributed to the technical physical cause of death.
Substance dependencies are generally more common in the male population, but the study found females aged 10 or older were more likely to suffer an illness related to a mental disorder.
China, North Korea, Japan and Nigeria were the only countries that had a significantly lower rate of death and disease related to mental disorders or addiction.
"Despite the personal and economic costs, treatment rates for people with mental and substance use disorders are low, and even in developed countries, treatment is typically provided many years after the disorder begins," Whiteford said.
"In all countries, stigma about mental and substance use disorders constrain the use of available resources as do inefficiencies in the distribution of funding and interventions. If the burden of mental and substance use disorders is to be reduced, mental health policy and services research will need to identify more effective ways to provide sustainable mental health services, especially in resource-constrained environments," he said.
The second study found opiate addiction (such as heroin) was responsible for the most drug related illnesses. The correlation was the strongest in developed countries such as the U.S. and the U.K.
