Nearly 3% of adults have attention-deficit and hyperactivity disorder (ADHD), although in the UK, most are undiagnosed. Adults with ADHD on average experience poorer educational and employment outcomes, worse physical and mental health and are more likely to die prematurely. No studies have yet used mortality data to examine the life expectancy deficit experienced by adults with diagnosed ADHD in the UK or worldwide.

This study used the life-table method to calculate the life-expectancy deficit for people with diagnosed ADHD using data from UK primary care.

A matched cohort study using prospectively collected primary care data (792 general practices, 9 561 450 people contributing eligible person-time from 2000–2019). We identified 30 039 people aged 18+ with diagnosed ADHD, plus a comparison group of 300 390 participants matched (1:10) by age, sex and primary care practice. We used Poisson regression to estimate age-specific mortality rates, and life tables to estimate life expectancy for people aged 18+ with diagnosed ADHD.

Around 0.32% of adults in the cohort had an ADHD diagnosis, ~1 in 9 of all adults with ADHD. Diagnoses of common physical and mental health conditions were more common in adults with diagnosed ADHD than the comparison group. The apparent reduction in life expectancy for adults with diagnosed ADHD relative to the general population was 6.78 years (95% CI: 4.50 to 9.11) for males, and 8.64 years (95% CI: 6.55 to 10.91) for females.

Adults with diagnosed ADHD are living shorter lives than they should. We believe that this is likely caused by modifiable risk factors and unmet support and treatment needs in terms of both ADHD and co-occurring mental and physical health conditions. This study included data from adults with diagnosed ADHD; the results may not generalise to the entire population of adults with ADHD, the vast majority of whom are undiagnosed.

Depression, anxiety and insomnia often co-occur. However, there is a lack of research regarding how they cluster and how this is related to medication used to treat them.

To describe the frequencies and associations between depression, anxiety and insomnia, and treatment for these conditions in primary care.

A retrospective cohort study using UK electronic primary care records. We included individuals aged between 18 and 99 years old with one or more records suggesting they had a diagnosis, symptom or drug treatment for anxiety, depression or insomnia between 2015 and 2017. We report the conditional probabilities of having different combinations of diagnoses, symptoms and treatments recorded.

There were 1 325 960 records indicative of depression, anxiety or insomnia, for 739 834 individuals. Depression was the most common condition (n = 106 117 records), and SSRIs were the most commonly prescribed medication (n = 347 751 records). Overall, individuals with a record of anxiety were most likely to have co-occurring symptoms and diagnoses of other mental health conditions. For example, of the individuals with a record of generalised anxiety disorder (GAD), 24% also had a diagnosis of depression. In contrast, only 0.6% of those who had a diagnosis of depression had a diagnosis or symptom of GAD. Prescribing of more than one psychotropic medication within the same year was common. For example, of those who were prescribed an SNRI (serotonin-norepinephrine reuptake inhibitor), 40% were also prescribed an SSRI (selective serotonin reuptake inhibitor).

The conditional probabilities of co-occurring anxiety, depression and insomnia symptoms, diagnoses and treatments are high.

Rates of diagnosed attention-deficit hyperactivity disorder (ADHD) may be increasing in the UK.

Estimate incidence and prevalence of ADHD diagnoses and ADHD prescriptions in UK adults and children in primary care.

We conducted a cohort study using IQVIA Medical Research Data, a UK primary care database. Rates of ADHD diagnoses and ADHD prescriptions were calculated between 2000 and 2018 for individuals aged 3–99 years, analysed by age, gender, social deprivation status and calendar year.

Of 7 655 931 individuals, 35 877 (0.5%) had ADHD diagnoses; 18 518 (0.2%) received ADHD medication prescriptions. Diagnoses and prescription rates were greater in men versus women, children versus adults, and deprivation status (nearly double in most deprived versus least deprived quintile). By 2018, the proportion of ADHD diagnoses was 255 per 10 000 (95% CI 247–263) in boys and 67.7 per 10 000 (95% CI 63.5–71.9) in girls; for adults, it was 74.3 per 10 000 (95% CI 72.3–76.2) in men and 20 per 10 000 (95%CI 19.0–21.0) in women. Corresponding figures for prescriptions were 156 per 10 000 (95% CI 150–163) in boys, 36.8 per 10 000 (95% CI 33.8–40.0) in girls, 13.3 per 10 000 (95% CI 12.5–14.1) in men and 4.5 per 10 000 (95% CI 4.1–5.0) in women. Except among 3- to 5-year-olds, the incidence and prevalence of ADHD diagnoses and prescriptions have increased from 2000 to 2018 in all age groups. The absolute increase was highest in children, but the relative increase was largest among adults (e.g. among men aged 18–29 years, approximately 20-fold and nearly 50-fold increases in diagnoses and prescriptions, respectively).

The incidence and prevalence of both ADHD diagnoses and medication are highest among children. Proportionally, rates increased most among adults during 2000–2018. ADHD diagnoses and prescriptions are associated with socioeconomic deprivation.

Smoking tobacco is regarded as an epiphenomenon in patients with schizophrenia when it may be causal. We aimed to examine whether smoking status is related to the onset of schizophrenia or the broader diagnosis of non-affective psychosis, including schizophrenia.

We used data from The Health Improvement Network primary care database to identify people aged 15–24 between 1 January 2004 and 31 December 2009. We followed them until the earliest of: first diagnosis of schizophrenia (or psychosis), patient left the practice, practice left THIN, patient died or 31 December 2014.

In men, incidence rates for schizophrenia per 100 000 person years at risk were higher in smoking initiators (non-smoker who became a smoker during the study) than in non-smokers (adjusted IRR 1.94; 95% CI 1.29–2.91) and higher still in smokers (adjusted IRR 3.32; 95% CI 2.67–4.14). Among women, the incidence rate of schizophrenia was higher in smokers than in non-smokers (adjusted IRR 1.50; 95% CI 1.06–2.12), but no higher in smoking initiators than non-smokers. For non-affective psychosis, the pattern was similar for men but more evident in women where psychosis incidence rates were higher in smoking initiators (adjusted IRR 1.90; 95% CI 1.40–2.56) and in smokers (adjusted IRR 2.13; 95% CI 1.76–2.57) than in non-smokers.

We found an important and strong association between smoking and incidence of schizophrenia. Smoking may increase risk through as yet unknown pathways or smoking may share genetic risk with schizophrenia and non-affective psychoses.

Recent media reports have focused on the large increase in antidepressants dispensed in England. We investigated this, focusing on selective serotonin reuptake inhibitors (SSRIs).

To examine the rate of initiation of SSRIs over time and changes over time in the duration of prescribing episodes.

We estimated initiation and duration of SSRI prescribing from 7 025 802 individuals aged over 18 years and registered with a general practice that contributed data to The Health Improvement Network.

Rates of SSRI initiation increased from 1.03 per 100 person-years in 1995 to 2.15 in 2001, but remained stable from then to 2012. The median duration of prescribing episodes increased from 112 to 169 days for episodes starting in 1995 to 2010.

Despite media reports describing an increasing rate of antidepressant prescribing, SSRI initiation rates have stabilised since 2001. However, our results suggest that individuals who take SSRIs are receiving treatment for longer.

There is a paucity of data describing how general practitioners (GPs) label or record depression.

To determine incidence and sociodemographic variation in GP-recorded depression diagnoses and depressive symptoms.

Annual incidence rates calculated using data from 298 UK general practices between 1996 and 2006, adjusted for year of diagnosis, gender, age and deprivation.

Incidence of diagnosed depression fell from 22.5 to 14.0 per 1000 person-years at risk (PYAR) from 1996 to 2006. The incidence of depressive symptoms rose threefold from 5.1 to 15.5 per 1000 PYAR. Combined incidence of diagnoses and symptoms remained stable. Diagnosed depression and symptoms were more common in women and in more deprived areas.

Depression recorded by general practitioners has lower incidence rates than depression recorded in epidemiological studies, although there are similar associations with gender and deprivation. General practitioners increasingly use symptoms rather than diagnostic labels to categorise people's illnesses. Studies using standardised diagnostic instruments may not be easily comparable with clinical practice.