Investigating the link between ADHD and depression

Victoria Powell, PhD Researcher, School of Medicine (Division of Psychological Medicine and Clinical Neuroscience)

During this year’s Children’s Mental Health Week, undoubtedly there will be children and adolescents with Attention-Deficit Hyperactivity Disorder (ADHD) receiving mental health support up and down the UK. ADHD is one of the most common neurodevelopmental disorders and it is associated with a range of mental health problems later in life including depression. 

A child with ADHD will typically have difficulty focusing on tasks and may at times feel so full of energy that they struggle to even sit still. This kind of hyperactivity may seem worlds apart from depression – a mental health condition characterised by low mood and energy amongst other symptoms. However, studies are increasingly showing a link between ADHD in childhood and depression in later life.

In fact, one study by Fergusson et al. in 2010 showed that of those with ADHD in adolescence, 50% had depression by early adulthood. However, while research shows that ADHD seems to be linked with depression later on, the reasons behind this link are still unclear. Investigating the risks that link ADHD and depression is essential in identifying how we might be able to treat or prevent depression in those with ADHD.

The focus of my PhD so far has been investigating the role of academic and friendship difficulties in the ADHD-depression link. Children often find that their ADHD makes it difficult to make and maintain good friendships, in addition to hindering progress at school. Both of these difficulties can also lead to depression. Therefore, I wanted to investigate whether there is a pathway by which some children with ADHD experience increased friendship and academic difficulties which in turn damages their self esteem and elevates depression risk.

My findings in a study of over 2000 individuals from the Avon Longitudinal Study of Parents and Children (ALSPAC) support this theory. Results showed that childhood ADHD symptoms are associated with adolescent depressive symptoms 10 years later, with friendship and academic attainment difficulties explaining around 15% and 20% of this ADHD-depression link, respectively. This remained the case even when we accounted for the potential effects of socioeconomic background, gender, childhood emotional problems and IQ on our results. This highlights friendship and academic difficulties as important potential targets of depression prevention and intervention programs in those with ADHD.

While drawing attention to the role of friendships and academic achievement is important however, this is far from the full picture of the ADHD-depression link. There will be many more routes and reasons behind the association of ADHD and depression, both environmental and genetic. Research is beginning to uncover these routes, hopefully with new clinical implications for depression prevention and treatment for children with ADHD on the horizon.

Get in touch with Victoria @VictoriaIPowell