Depression is a significant mental health concern affecting the overall well-being of adolescents and young adults. Recently, the prevalence of depression has increased among young people. Nonetheless, there is little research delving into the longitudinal epidemiology of adolescent depression over time.

To investigate the longitudinal epidemiology of depression among adolescents and young adults aged 10–24 years.

Our research focused on young people (aged 10–24 years) with depression, using data from the Global Burden of Diseases, Injuries, and Risk Factors Study 2019. We explored the age-standardised prevalence, incidence and disability-adjusted life-years (DALYs) of depression in different groups, including various regions, ages, genders and sociodemographic indices, from 1990 to 2019.

The prevalence, incidence and DALYs of depression in young people increased globally between 1990 and 2019. Regionally, higher-income regions like High-Income North America and Australasia recorded rising age-standardised prevalence and incidence rates, whereas low- or middle-income regions mostly saw reductions. Nationally, countries such as Greenland, the USA and Palestine reported the highest age-standardised prevalence and incidence rates in 2019, whereas Qatar witnessed the largest growth over time. The burden disproportionately affected females across age groups and world regions. The most prominent age effect on incidence and prevalence rates was in those aged 20–24 years. The depression burden showed an unfavourable trend in younger cohorts born after 1980, with females reporting a higher cohort risk than males.

Between 1990 and 2019, the general pattern of depression among adolescents varied according to age, gender, time period and generational cohort, across regions and nations.

The longitudinal course of late-life depression remains under-studied.

To describe transitions along the depression continuum in old age and to identify factors associated with specific transition patterns.

We analysed 15-year longitudinal data on 2745 dementia-free persons aged 60+ from the population-based Swedish National Study on Aging and Care in Kungsholmen. Depression (minor and major) was diagnosed according to the Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition, Text Revision; subsyndromal depression (SSD) was operationalised as the presence of ≥2 symptoms without depression. Multistate survival models were used to map depression transitions, including death, and to examine the association of psychosocial (social network, connection and support), lifestyle (smoking, alcohol consumption and physical activity) and clinical (somatic disease count) factors with transition patterns.

Over the follow-up, 19.1% had ≥1 transitions across depressive states, while 6.5% had ≥2. Each additional somatic disease was associated with a higher hazard of progression from no depression (No Dep) to SSD (hazard ratio 1.09; 1.07–1.10) and depression (Dep) (hazard ratio 1.06; 1.04–1.08), but also with a lower recovery (HRSSD−No Dep 0.95; 0.93–0.97 [where ‘HR’ refers to ‘hazard ratio’]; HRDep−No Dep 0.96; 0.93–0.99). Physical activity was associated with an increased hazard of recovery to no depression from SSD (hazard ratio 1.49; 1.28–1.73) and depression (hazard ratio 1.20; 1.00–1.44), while a richer social network was associated with both higher recovery from (HRSSD−No Dep 1.44; 1.26–1.66; HRDep−No Dep 1.51; 1.34–1.71) and lower progression hazards to a worse depressive state (HRNo Dep−SSD 0.81; 0.70–0.94; HRNo Dep−Dep 0.58; 0.46–0.73; HRSSD−Dep 0.66; 0.44–0.98).

Older people may present with heterogeneous depressive trajectories. Targeting the accumulation of somatic diseases and enhancing social interactions may be appropriate for both depression prevention and burden reduction, while promoting physical activity may primarily benefit recovery from depressive disorders.

Individuals with schizophrenia face high mortality risks. The effects of lipid-modifying agents on this risk remain understudied.

This study was conducted to investigate the effects of lipid-modifying agents on mortality risk in people with schizophrenia.

This nationwide cohort study collected the data of people with schizophrenia from Taiwan's National Health Insurance Research Database for the period between 1 January 2001 and 31 December 2019. Multivariable Cox proportional hazards regression with a time-dependent model was used to estimate the hazard ratio for mortality associated with each lipid-modifying agent.

This study included 110 300 people with schizophrenia. Of them, 22 528 died (19 754 from natural causes and 1606 from suicide) during the study period, as confirmed using data from Taiwan's national mortality database. The use of lipid-modifying agents was associated with reduced risks of all-cause (adjusted hazard ratio [aHR]:0.37; P < 0.001) and natural (aHR:0.37; P < 0.001) mortality during a 5-year period. Among the lipid-modifying agents, statins and fibrates were associated with reduced risks of all-cause mortality (aHRs:0.37 and 0.39, respectively; P < 0.001 for both) and natural mortality (aHRs: 0.37 and 0.42, respectively; P < 0.001 for both). Notably, although our univariate analysis indicated an association between the use of lipid-modifying agents and a reduced risk of suicide mortality, the multivariate analysis revealed no significant association.

Lipid-modifying agents, particularly statins and fibrates, reduce the risk of mortality in people with schizophrenia. Appropriate use of lipid-modifying agents may bridge the mortality gap between these individuals and the general population.