Mental Health Blog

Is it ADHD? Or something else?

photo of angry child with clenched fist

Attention-deficit hyperactivity disorder (ADHD) is one of the most common behavioral health disorders, affecting approximately 9% of all children and adolescents.[1] About 75% of pediatric patients with ADHD have comorbid mental health conditions, ranging from oppositional-defiant disorder to anxiety and mood disorders.[2]

What is a busy clinician to do? How do you discern whether a child who is, say, having difficulty focusing at school and at home has ADHD, anxiety, both, or something else? This question was the subject of a recent REACH webinar on differential diagnosis and treatment of ADHD and comorbid conditions.

In that webinar, Anni Layne Rodgers, general manager of ADDitude magazine, emphasized that “comorbidities with ADHD are the rule, not the exception.” In revising its ADHD guidelines in 2019, the American Academy of Pediatrics added a recommendation on screening for comorbid conditions, listing physical, developmental, and emotional or behavioral conditions.[3

In an informal ADDitude reader survey, parent respondents listed anxiety as the most common co-occurring mental health disorder among their children with ADHD. A study by researchers from the Centers for Disease Control and Prevention listed behavior disorders as the most common comorbid condition, followed by anxiety and depression.[1]

Rachel Petersen-Nguyen, MD, REACH faculty trainer and pediatrician at the Mayo Clinic, described how she approaches patients who present with attention problems. She uses the Vanderbilt questionnaire as an initial assessment. This tool, which has parent and teacher versions, helps clinicians discern whether symptoms appear in more than one setting, as required by DSM-5 (Diagnostic and Statistical Manual of Mental Health Disorders). The Vanderbilt questionnaires also help clinicians discern how many symptoms the child exhibits and how much impairment those symptoms cause.

The next question, Dr. Petersen-Nguyen said, is to ask, “Could these symptoms be caused by anything else?” Physical issues could include hearing or vision impairment or any disorder that affects sleep. 

In fact, Dr. Petersen-Nguyen said that, when multiple issues present at once, she starts by helping with sleep. The third panelist, psychologist Jennifer Erickson, PhD, agreed: “Sleep is number 1!” Whether lack of sleep causes ADHD symptoms or anxiety symptoms cause lack of sleep, a first step is to work with patients to understand what keeps them from getting a good night’s sleep and what they can do about it. Dr. Erickson pointed out that, if a patient can’t do their sleep hygiene “homework,” that inability is additional evidence for a diagnosis of ADHD.

After ruling out physical causes, clinicians need to look for emotional or developmental conditions. Again, Dr. Petersen-Nguyen turns to validated screening tools:

  • SCARED for anxiety
  • PHQ-9-A for depression
  • CRAFFT for substance use

“After I have the results from the questionnaires, I talk with the patient,” said Dr. Petersen-Nguyen. “I ask, ‘What are the great things about you? What are your challenges? Where do you need help?’” 

One of the things she wants to nail down is which disorder is causing the most impairment—because that’s where she will focus her initial treatment efforts. She gave an example of a teen patient with high IQ who was diagnosed with autism and also had ADHD. This patient subsequently developed depression—treatment of which then became Dr. Petersen-Nguyen’s top priority. “We need to focus treatment where it can be most effective,” she said.

Dr. Petersen-Nguyen described ways in which diagnosis of comorbid conditions can vary by patient age. “With young children, we might see things like anxiety and maybe autism, whereas depression is uncommon. In teens, we’ll still see anxiety, and depression and substance abuse become more common. Autism spectrum disorders, if present, have usually been diagnosed before the teen years.” 

In the webinar, Dr. Erickson focused on social, emotional, and environmental factors affecting diagnosis. For example, anxiety can result from issues with working memory. If a child can’t gather their thoughts when the teacher calls on them, they may have a fight-or-flight reaction. Patients whose fears continue to grow may succumb to depression if they start to think, for example, “What’s the use? I can’t do well in school.” 

Dr. Erickson emphasized that, if a child says they are anxious or sad, it’s important to try to understand what experience the child is describing. If it emerges that the child is anxious or sad because they can’t focus in school, then ADHD may be a root cause.

Panelists agreed that clinicians should consider exposure to traumatic experiences as they diagnose ADHD. Lisa Hunter Romanelli, PhD, REACH CEO and webinar moderator, pointed out that a child who repeatedly re-experiences a traumatic event will naturally have trouble paying attention in school. Dr. Petersen-Nguyen described a recent patient: “I thought they had ADHD. Then I found out they had a recent trauma, so I decided it must be traumatic stress and not ADHD. Then I realized it could be both!”



  1. Danielson ML, Bitsko RH, Ghandour RM, Holbrook JR, Kogan, MD, Blumberg, SJ. Prevalence of parent-reported ADHD diagnosis and associated treatment among U.S. children and adolescents. J Clin Child Adolesc Psychol. 2016;47(2):199-212. doi:10.1080/15374416.2017.1417860
  2. Banaschewski T, Becker K, Döpfner M, Holtmann M, Rösler M, Romanos M. Attention-deficit/hyperactivity disorder. Dtsch Arztebl Int. 2017;114(9):149-159. doi:10.3238/arztebl.2017.0149
  3. Wolraich ML, Hagan JF Jr, Allan C, et al. Clinical practice guideline for the diagnosis, evaluation, and treatment of attention-deficit/hyperactivity disorder in children and adolescents. Pediatrics. 2019;144(4):e20192528. doi:10.1542/peds.2019-2528



In addition to the articles cited above, clinicians can also use the following resources:

Register for courses

Please select your profession in order to view a drop down menu of applicable course selections.

“The REACH Institute Video Testimonial: Hilary