Over one billion people around the world are living with mental health and addiction problems, a major new study has shown.

According to the Global Burden of Disease (GBD) study's latest estimates for the state of the world's health, a total of 1.1 billion people have mental health and substance use disorders.

Furthermore, major depressive disorders rank in the top 10 causes of ill health in almost every country in the world.

The GBD is the only annual, comprehensive assessment of global trends in health. It provides estimates on over 330 diseases in 195 countries and territories worldwide and it latest figures relate to 2016.

The study shows that last year, there were 128.8 million live births and 54.7 million deaths. Mortality rates have declined across all age groups, with the best progress made in children under the age of five.

In fact, last year, deaths among children under the age of five fell to fewer than five million for the first time. In 1970, over 16 million children under the age of five died.

The average global life expectancy for women is now 75.3 years and 69.8 years for men, however this differs from country to country. Japan has the highest life expectancy (83.9 years for both men and women combined), while the Central African Republic has the lowest life expectancy, at just 50.2 years.

Non-communicable diseases accounted for 72% of all deaths - that is over 39 million people - last year. The leading cause of premature mortality in most regions was heart disease.

Globally, heart disease caused 9.48 million deaths last year, an increase of 19% since 2006. Diabetes caused 1.43 million deaths, a jump of 31% since 2006.

Overall, deaths from infectious diseases have fallen. For example, 1.21 million people died last year from tuberculosis (TB), a 20% fall since 2006. However, the report also found an increase in deaths due to drug-resistant tuberculosis (TB). Some 10,900 such deaths were reported in 2016 - a 67% increase since 2006.

Meanwhile, the study found that tobacco use caused 7.1 million deaths last year, while poor diet was linked with almost one in five deaths.

In particular, diets that were low in whole grains, fruit, nuts, seeds and fish oils, and high in salt were the most common dietary risk factors.

The study also noted that high blood glucose, high blood pressure, high body mass index (BMI), and high total cholesterol, were all in the top 10 leading risk factors for death for men and women globally.

Because of the strong links between these risks, the researchers explained that the true driver is likely to be diet and BMI, exacerbated by blood glucose levels and high blood pressure.

Meanwhile, the study also noted that despite a fall in the number of deaths related to self-harm and interpersonal violence, there was a rise in the number of deaths from firearms last year.

It also noted that since 2006, there has been an increase in the number of deaths from conflict and terrorism, largely as a result of conflicts in north Africa and the Middle East.

"Our findings indicate people are living longer and, over the past decade, we identified substantial progress in driving down death rates from some of the world's most pernicious diseases and conditions, such as under age-5 mortality and malaria.

"Yet, despite this progress, we are facing a triad of trouble holding back many nations and communities - obesity, conflict, and mental illness, including substance use disorders," commented Dr Christopher Murray, director of the Institute for Health Metrics and Evaluation (IHME) at the University of Washington, Seattle.

Details of these findings are published in the medical journal, The Lancet.