ADHD & Depression in Young People

Young people with ADHD are approximately five times more likely to develop depression than their peers, and when both conditions co-occur, outcomes are considerably more serious, including a substantially elevated suicide risk compared to either condition alone. Despite this, standard depression interventions appear to be notably less effective for young people with ADHD. This points to a critical gap: before better treatments can be developed, the mechanisms connecting ADHD to depression need to be understood. This three-year project (September 2023 – August 2026), led by Lucy Riglin at Cardiff University's Wolfson Centre, uses two large UK longitudinal datasets to investigate how and why ADHD leads to depression across childhood, adolescence, and young adulthood. The study is pre-registered on OSF.

Young people with ADHD are around five times more likely to experience depression than those without, and when both conditions co-occur, suicide risk is elevated beyond either alone.

The Research

The project draws on two large existing UK datasets: the TED twin dataset from King's College London and the Avon (ALSPAC) dataset from the University of Bristol, covering young people aged 4–25 across approximately eight data collection timepoints. Rather than requiring a formal diagnosis, the study works with symptom-level measures, capturing the full spectrum of ADHD and depressive experience, including the many young people who have not received a clinical diagnosis or are still on waiting lists for assessment.

The project has four main aims:

1. Trajectories. Examining how the association between ADHD and depression develops across childhood, adolescence, and young adulthood, including whether depression starts earlier or lasts longer in young people with ADHD, how this varies by gender, and whether particular symptom profiles are associated with ADHD at different ages.
2. Cognitive and emotional pathways. Testing whether characteristics related to cognition (impulsivity, negative cognitive styles) and emotion regulation (irritability, anxiety) mediate the link between ADHD and depression, with implications for future intervention targets.
3. Relationship pathways. Examining the extent to which difficulties in relationships with parents, friends, and romantic partners contribute to the ADHD–depression link at different developmental stages - relevant given that several existing depression therapies aim to improve social relationships.
4. Genetic and environmental contributions. Using the twin design to estimate the genetic overlap between ADHD and depression, and testing whether identified mediating factors act as causal drivers or markers of shared genetic risk. If a factor is causal, targeting it in interventions is more likely to reduce depression in young people with ADHD.

The waiting time for an ADHD assessment in the UK can exceed three years.

My Involvement

I am involved in this project as a member of the Young People's Advisory Group (YPAG), convened through McPin. The group meets every six months to review plans and emerging findings, with opportunities to provide feedback on written and video updates between meetings. There is also scope for co-authorship on research papers and involvement in creating dissemination materials for young people and families affected by ADHD.

A recurring theme in YPAG discussions has been format. How research reaches the people it is meant to help depends heavily on medium and channel, and for a project focused on ADHD, accessible and varied output is especially important. The group has discussed infographics, short-form video, audio, and social media as complementary channels, with an emphasis on specificity over generic symptom content and clear signposting to appropriate support services.