Example 8: The very high cumulative prevalence of psychiatric conditions over the life course. We reported that the prevalence of anxiety, depression, and substance dependence is about twice as high as the mental health community has been led to believe. It depends on how you measure mental disorder. By using the long-term Dunedin Study tracking a thousand New Zealanders from birth to early midlife we showed that people significantly underreport the amount of mental illness they have suffered when they are asked to recall their history in diagnostic interviews years after the fact [69, 70]. Since 2010, our initial finding has been replicated by four other cohort studies (in Oregon, Minnesota, North Carolina, and Baltimore). As a result of this provocative new finding, researchers are beginning to ask why so many people experience a disorder at least once during their lifetimes and what this means for the way we define mental health, deliver psychiatric services, and count the economic burdens of mental illness [71, 72]. At the very least, the finding that most of us will experience an episode of mental disorder if we live long enough should help reduce the stigma against mental illness.
