Summary: Yes, having ADHD can increase risk of depression. Having ADHD doesn’t cause depression, but having a diagnosis of attention-deficit hyperactivity disorder (ADHD) is associated with an increased risk of developing depressive symptoms and major depressive disorder (MDD).
Key Points:
- New studies explore the relationship between ADHD and depressive symptoms common to MDD.
- One recent study examines whether having ADHD + Insomnia is associated with increased risk of depression.
- The same study examines whether ADHD + Insomnia is associated with decreased quality of life.
- Providers, individuals, and families can use this new information to tailor ADHD treatment to meet specific symptom profiles and treatment needs.
Attention-Deficit Hyperactivity Disorder (ADHD) and Mental Health Disorders
Publications from the Centers for Disease Control (CDC) and the American Psychiatric Association (APA) offer the following definition and types of ADHD:
“Attention-deficit/hyperactivity disorder (ADHD) is one of the most common mental disorders affecting children. Symptoms of ADHD include inattention, hyperactivity, and impulsiveness. ADHD is most often diagnosed during childhood or adolescence but may be diagnosed during adulthood. There are three primary types of ADHD: the inattentive type, the hyperactive/impulsive type, and the combined type.”
Data provided by the non-profit group Children and Adults with Attention Deficit Hyperactivity Disorder (CHADD) shows the following prevalence of ADHD among children and adults:
Children age 3-17:
- Ever diagnosed with ADHD: 11.4%
- Current ADHD diagnosis: 10.5%
- 3-5: 2.4%
- 6-11: 11.5%
- 12-17: 15.5%
Adults age 18+, current diagnosis:
- 18-24: 21.7%
- 25-29: 62.8%
- 50-64: 10.6%
- 65+: 4.9%
The presence of ADHD can cause significant disruption in key areas of life, including impairing work and school performance. In addition, diagnosis of ADHD is associated with increased risk of developing mental health disorders alongside ADHD, called co-occurring conditions.
Let’s take a look at the rates of co-occurring conditions among people with ADHD.
Prevalence of co-occurring conditions among children 3-17 with ADHD:
- Any co-occurring condition: 77.9%
- Behavior/conduct problems: 30.9%
- Anxiety disorders: 39.1%
- Depressive disorders: 18.9%
- Autism spectrum disorders (ASD): 14.4%
Prevalence of co-occurring conditions among adults 18+ with ADHD:
- Any co-occurring condition: ~80%
- Alcohol/substance misuse: ~45%
- Anxiety disorders: ~44%
- Depressive disorders: ~27%
- Bipolar disorder: ~44%
Given the widespread prevalence of ADHD in children and adults and the widespread prevalence of co-occurring conditions among people with ADHD, recent research has examined the connection between ADHD and one of the most common mental health disorders, depression.
ADHD and Increase of Depression Risk: What’s the Cause?
One group of researchers hypothesized that insomnia and sleep-related factors explained the prevalence of depression among people with ADHD. The authors of the study “Associations Of ADHD Traits, Sleep/Circadian Factors, Depression and Quality of Life” describe their research:
“We investigated whether disruption of self-reported sleep and circadian factors mediate the associations of ADHD traits with depression symptom severity and quality of life (QoL).”
To identify a connection between sleep issues such as insomnia and depression among people with ADHD, the research team recruited 1364 participants from a population-wide survey – the Netherlands Sleep Registry – who completed the following questionnaires:
- Generic sociodemographic questionnaire
- Adult ADHD Rating Scale (ASRS)
- Hospital Anxiety and Depression Scale (HADS)
- Satisfaction With Life Scale (SLS), a Quality of Life (QoL) metric
- Cantril Ladder (CL), QoL metric
- Insomnia Severity Index (ISI)
- Pittsburgh Sleep Quality Index (PSQI)
- Munich Chronotype Questionnaire (MCQ)
After extensive analysis, they found significant statistical association between high levels of ADHD symptoms and the following problems:
- Depression symptom severity
- Lower quality of life
- Insomnia severity
- Lower sleep quality
While their results established significant statistical relationships between ADHD, depression, quality of life, and insomnia, they disproved their primary hypothesis:
No sleep or circadian factor significantly explained the relationship between ADHD and increased depression, and no sleep or circadian factor significantly explained the relationship between ADHD and decreased quality of life.
However, the results also showed severe insomnia was associated with:
- Increased ADHD symptoms
- Decreased quality of life
This research found that insomnia and sleep issues did not explain the increased levels of depression among people with ADHD.
So, what explains the connection?
Why Does ADHD Increase Depression Risk?
The authors of the study we share above conclude it’s not sleep issues or insomnia. Another study, this one published in 2020, called “ADHD And Depression: Investigating A Causal Explanation,” took another approach. Here’s how the authors describe the research effort:
“Attention-deficit hyperactivity disorder (ADHD) is associated with later depression and there is considerable genetic overlap between them. This study investigated if ADHD and ADHD genetic liability are causally related to depression using two different methods.”
Specifically, the research team examined the association between diagnosis of ADHD at age 7 and the presence of depression between ages 18 and 25, i.e. young adulthood.
To conduct the study, the researchers analyzed data from over 8,000 participants in the Avon Longitudinal Study of Parents and Children (ALSPAC). They used a Genome-Wide Association Study (GWAS) to assess the presence of ADHD among the study participants and the impact of genetics, i.e. heredity, on the relationship between ADHD and depression.
Here’s what they found:
- Childhood ADHD was associated with a 35% increased risk of depression during young adulthood.
- Genetic specifiers for ADHD were associated with a 21% increased risk of depression in a model using a narrow definition of depression.
- Genetic specifiers for ADHD were associated with a 7% increased risk of depression in a model using a broad definition of depression.
Here’s how the researchers characterize these outcomes:
“Our findings suggest that ADHD increases the risk of depression later in life and are consistent with a causal effect of ADHD genetic liability on subsequent major depression.”
In other words, the data show that with a broad definition of depression, genetic factors associated with ADHD explain 60 percent of the increased risk of depression among people with ADHD. Using a narrow definition of depression, genetic factors associated with ADHD explain 20 percent of the increased risk of depression among people with ADHD.
How This Research Helps Us Understand ADHD and Risk of Depression
The first study we discuss above shows that as the presence and severity of ADHD symptoms increase, depressive symptoms increase, quality of life decreases, sleep quality decreases, and insomnia increases. However, insomnia did not explain the increases in depression, but insomnia was associated with increased ADHD symptoms and decreased overall quality of life.
The second study shows us that among people diagnosed with ADHD at age 7, genetic factors, i.e. heredity, increase risk of depression by 21 percent, representing 60 percent of the overall increased risk of depression.
Together, these studies help us in at least two ways:
- Highlighting the importance of gathering family medical history, particularly family history of ADHD. If a patient has ADHD and family history of ADHD, their genetic profile may increase risk of depression.
- Understanding the impact of poor sleep on people with ADHD. People with severe insomnia show elevated ADHD symptoms and decreased quality of life.
While the first takeaway is broad, the second can help us help our patients in specific ways. For example, to prevent exacerbated ADHD symptoms and decreased quality of life, we can teach patients with ADHD the essentials of sleep hygiene, the impact of diet and exercise on sleep, and techniques that promote stress reduction and good sleep, such as progressive muscular relaxation, mindful meditation, and simple, calming breathing exercises.
