The world faces “an emerging crisis” of higher death rates among teenagers and young adults, according to a major study on the causes of death and disability worldwide.
The reasons vary from drug and alcohol use, and suicide in North America, to infectious diseases and injuries in sub-Saharan Africa, the researchers said, but warned that their data should serve as “a wake-up call”.
The study also found that chronic diseases such as heart disease and diabetes now accounted for two-thirds of all ill health and that mental health problems were surging.
Half of the world’s disease burden was preventable, researchers calculated, driven by risks that could be reduced, such as high blood pressure, air pollution, smoking and obesity.
The Global Burden of Disease study was carried out by a network of 16,500 scientists using more than 300,000 data sources. It is published in the Lancet and was presented at the World Health Summit in Berlin on Sunday.
It found that, as of 2023, death rates had fallen overall in all 204 countries and territories, and global life expectancy had recovered from a dip caused by the Covid-19 pandemic.
It stands at 76.3 years for women and 71.5 for men, more than 20 years higher than in 1950 – although “stark geographic differences” remain, ranging from 83 years in high-income regions to 62 in sub-Saharan Africa.
However, the authors said they were particularly concerned about stubbornly higher or rising death rates among teenagers and young adults.
In North America and parts of Latin America, the rises were driven by suicide and consumption of drugs and alcohol.
“Very marked increases” among teenagers and young adults “certainly got our attention when we were looking at the data”, said Dr Christopher Murray, director of the Institute for Health Metrics and Evaluation (IHME) at the University of Washington’s school of medicine.
Rising deaths in younger adults, particularly in North America, he said, were “very tied up with the rise of anxiety and depression in young people, particularly women”. While the rise of mental health disorders had received much attention, he said, there was still a lot of debate around the causes.
“Is this social media? Is this [electronic] devices? Is this broader social trends on parenting? We know it was made worse by Covid. So there’s a lot of controversy, I’d say, in the psychiatric epidemiology and general social commentary about the causes around mental health. And so that’s a problem for coming up with solutions.”
In sub-Saharan Africa, modelling advances revealed that deaths in children aged five to 14 since 1950 had been higher than previously thought, with drivers including infectious diseases and unintentional injuries.
For girls and women aged 15 to 29, the death rate was 61% higher than previously estimated, mostly due to deaths in pregnancy or childbirth, road injuries and meningitis.
Murray said: “The evidence presented in the Global Burden of Disease study is a wake-up call, urging government and healthcare leaders to respond swiftly and strategically to the disturbing trends that are reshaping public health needs.”
Dr Githinji Gitahi, chief executive of Amref Health Africa, said that the 60% of people in Africa aged under 25 represented “an incredible potential”.
“Health is the most powerful investment in this, and integrated care is the key, when we face the triple burden of cost of living, rising non-communicable diseases and communicable disease outbreaks, and climate change,” he said.
“Siloed approaches to healthcare are failing our young people. Diseases like malaria, HIV and tuberculosis still claim too many young lives due to weak health systems, disrupted care and vaccine gaps.
“At the same time, the exponential rise in non-communicable diseases among younger Africans is not just a future threat; they claim young lives daily, now. There is too little regulation of food production and scant nutrition education in urban environments that are changing lifestyles and outlooks.”
He called for “stronger health systems founded on real youth-centred public health investment”.
Emmanuela Gakidou, senior author and professor at IHME, warned that existing progress in low-income regions was at risk due to recent international aid cuts. She said: “These countries rely on global health funding for life-saving primary care, medicine and vaccines. Without it, the gap is sure to widen.”
The Global Burden of Disease study is partly funded by the Gates Foundation, which is a philanthropic organisation that also contributes funding to support the editorially independent global development section of the Guardian