Study: ADHD Increases Risk of Depression, PTSD, Anorexia, and Self-Harm
Major depressive disorder increases an individual’s chance of having ADHD by 76%, and attention deficit hyperactivity disorder is associated with elevated risk for PTSD, anorexia nervosa, and suicide attempts, a new study found.
September 8, 2023
A bi-directional link between attention deficit hyperactivity disorder (ADHD) and major depressive disorder (MDD) means that 35% to 50% of all adults with ADHD will experience one or more depressive episodes in their lives, according to a new study published in the journal BMJ Mental Health.1 The research, which demonstrates “a familial association and shared genetic risk between ADHD and depression,” also found that patients with ADHD are at elevated risk for post-traumatic stress syndrome (PTSD), anorexia nervosa (AN), and suicide attempts.
Observational studies have shown past associations between ADHD and mood and anxiety disorders; however, ADHD’s connections to other mental health conditions have remained somewhat less clear. Using the Mendelian randomization (MR) method, researchers in this study gathered genetic evidence to determine potential links between ADHD and MDD, bipolar disorder, anxiety disorder, schizophrenia, PTSD, AN, and suicide attempts.
The MR data and subsequent meta-analyses revealed the following relationships, among others:
- People with ADHD were 9% more likely to develop MDD
- An MDD diagnosis increases the risk for ADHD by 76%
- Individuals with ADHD were 30% more likely to attempt suicide
- Individuals with ADHD and MDD were 42% more likely to attempt suicide
Other findings showed that ADHD increased the chances of developing PTSD by 18%. The risk for PTSD rose significantly (67%) in people with ADHD and depression. People with ADHD were 28% more likely to develop AN. However, the researchers did not find a link between MDD and development of AN.
The study did not prove any direct cause-and-effect relationships, only associations.
The connections between ADHD and depression echo the results of a recent ADDitude survey of 1,500 readers. The survey revealed that 70% of adults with ADHD said they also have depression; in the general population, this number is 8%.
Despite prevailing research that general anxiety disorder (GAD) is one of the most common ADHD comorbidities2, the study did not find a causal link between GAD and ADHD. (The ADDitude survey found that 72% of adults with ADHD said they have anxiety.)
Further, researchers did not find notable associations between ADHD and bipolar disorder or schizophrenia.
While the study’s results weren’t surprising, they do underscore the importance of conducting comorbid psychiatric evaluations in individuals with ADHD. “This study opens new insights into the paths between psychiatric disorders. Thus, in clinical practice, patients with ADHD should be monitored for the psychiatric disorders included in this study, and preventive measures should be initiated, if necessary,” the researchers wrote.
Complicating clinicians’ evaluations is the fact that symptoms of ADHD and MDD are easily mistaken for one another. Though comorbidity is common, so too is misdiagnosis, especially among women whose ADHD symptoms are mistaken for depression.
“The most common misdiagnosis of adolescents and adults with ADHD is major depressive disorder,” William Dodson, M.D., LF-APA, told ADDitude. “This incorrect diagnosis happens frequently, and it carries serious consequences. Before receiving the correct ADHD diagnosis, the average patient has taken 2.6 different antidepressant medications without any benefits — diagnosis and treatment delays could be between six and seven years.”
The researchers cited several limitations to their study. For example, the study only included people of European ancestry, and they said the same gene might be associated with different traits, making pinpointing the relevant causal effect difficult.
If you or someone you know is struggling with mental health, help is available. Dial or text 988 or visit 988lifeline.org for free and confidential support.
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1Meisinger, C. & Freuer, D., (2023) Understanding the Causal Relationships of Attention Deficit/Hyperactivity Disorder with Mental Disorders and Suicide Attempt: A Network Mendelian Randomisation Study. BMJ Mental Health. doi.org/10.1136/bmjment-2022-300642