Mortality in individuals with childhood ADHD or subthreshold symptoms – a prospective perinatal risk cohort study over 40 years

Abstract

Background Attention-deficit/hyperactivity disorder (ADHD) is associated with negative life outcomes and recent studies have linked it to increased mortality. These studies have examined nationwide registers or clinic-referred samples and mostly included participants up until the age of 30. No studies have investigated mortality associated with subthreshold levels of ADHD symptoms. Our aim was to analyze mortality in a perinatal risk cohort of 46-year-old adults with childhood ADHD (cADHD) and milder childhood attention problems (including hyperactivity and inattention; cAP) compared with a group with similar birth risks but no or low levels of childhood ADHD symptoms (Non-cAP). Causes of death obtained from a national register were examined. Methods Mortality was analyzed with Cox proportional hazard models for all-cause mortality, cause-specific mortality (natural and unnatural causes), and age-specific mortality (under and over age 30). All models were adjusted with gender. The total n in the study was 839 (cADHD n = 115; cAP n = 216; Non-cAP n = 508). Results By the age of 46, 11 (9.6%) deaths occurred in the cADHD group, 7 (3.2%) in the cAP group, and 20 (3.9%) in the Non-cAP group. The cADHD group had the highest mortality risk (adjusted hazard ratio = 2.15; 95% CI 1.02, 4.54). Mortality was not elevated in the cAP group (adjusted hazard ratio = 0.72; 95% CI .30, 1.72). Mortality in the cADHD group was mainly attributed to unnatural causes of death (adjusted hazard ratio = 2.82; 95% CI 1.12, 7.12). The mortality risk in the cADHD group was sixfold before age 30 (adjusted hazard ratio = 6.20; 95% CI 1.78, 21.57). Conclusions Childhood ADHD was associated with a twofold risk of premature death by the age of 46 in this prospective longitudinal cohort study. Our results corroborate previous findings and the morbidity of ADHD. Subthreshold levels of childhood ADHD symptoms were not linked to increased mortality. Our results suggest that mortality risk is higher in young than middle adulthood. Future studies should examine mortality associated with ADHD in different ages in adulthood to identify those in greatest risk of premature death.

Research Review: A systematic review and meta‐analysis of infant and toddler temperament as predictors of childhood attention‐deficit/hyperactivity disorder

“…Longitudinal studies of children treated for ADHD have found continued adverse outcomes in adulthood including lower educational achievement, greater occupational difficulties, interpersonal conflict, more frequent motor vehicle accidents and traffic violations, substance use problems, and suicide (Barkley, 2014; Chronis‐Tuscano et al., 2010; Molina et al., 2009; Shaw et al., 2012). More recently, it has been suggested that individuals with childhood ADHD have a 9–13‐year reduction in healthy life expectancy (Barkley, 2018; Schiavone et al., 2022). Given the significant negative long‐term outcomes of ADHD, there is a growing interest in identifying early signals of risk for ADHD before the full onset of the disorder.…”

Training and specialisation of psychiatrists in ADHD

“…Adverse outcomes for ADHD sufferers, especially if they are untreated, can include social and relationship problems, delinquency, substance abuse, increased rates of communicable diseases, accidents and injuries, problems at school and educational underachievement, under-employment and occupational problems and increased rates of homelessness. 3,6,7 ADHD is associated with increased mortality attributed to unnatural causes. 3,5,6 ADHD sufferers are over-represented in the criminal justice system in Australia.…”

“…3,6,7 ADHD is associated with increased mortality attributed to unnatural causes. 3,5,6 ADHD sufferers are over-represented in the criminal justice system in Australia. 5 Adverse outcomes can be reduced during periods of treatment.…”

State of the Evidence for Use of Psychotropic Medications in School-Age Youth

“…Subthreshold symptoms may result in a diagnosis of Other Specified ADHD or Unspecified ADHD. An ADHD diagnosis in childhood is associated with poor health outcomes, and a recent study found a twofold risk for premature death by the age of 46 [ 42 ]. Clinicians should recognize that the presentation of hyperactive and impulsive symptoms are associated with a range of negative outcomes, including peer rejection, aggression, risky behaviors, and accidental injuries [ 39 ].…”