A GLOBAL study has found one in two people will develop a mental health disorder in their lifetime. Prof John McGrath from the University of Queensland’s Brain Institute, Prof Ronald Kessler from Harvard Medical School, and their colleagues from 27 other countries, analysed data from more than 150,000 adults across 29 countries between 2001 and 2022, taken from the largest-ever coordinated series of face-to-face interviews, in the World Health Organisation’s World Mental Health Survey initiative. Lead author McGrath said the results demonstrate the high prevalence of mental health disorders, with 50% of the population developing at least one disorder by the age of 75. “The most common were mood disorders such as major depression or anxiety,” McGrath explained. “We also found the risk of certain mental disorders differed by sex.” The three most common mental health disorders among women are depression, specific phobia, and post-traumatic stress, while in men the most common include alcohol abuse, depression and specific phobia. The research also found mental health disorders typically first emerge in childhood, adolescence or young adulthood. “The peak age of first onset was at 15 years old, with a median age of onset of 19 for men and 20 for women,” McGrath concluded.