10 Commonly Misdiagnosed ADHD Symptoms

Attention deficit disorder (ADHD or ADD) is a lot more than inattention and hyperactivity, though these are the symptoms that most commonly lead to a diagnosis. Many of the less-known ADHD symptoms — working memory and executive function deficits, difficulty sleeping, and irritability, for example — also show up with mood disorders, autism, anxiety, and other brain-based conditions. Getting an accurate diagnosis often hinges on a patient's understanding of the 10 symptoms that commonly lead to an ADHD misdiagnosis. 

Mood swings are most commonly associated with bipolar disorder, a condition characterized by dramatic shifts from euphoric mania to crippling depression. But people have ADHD mood swings, too: they’re deeply passionate, and have strong emotional reactions that can change their mood dramatically. Bipolar individuals, on the other hand, typically shift moods without a “trigger” and are slower to move from depression to mania, or vice versa. To make a correct diagnosis, doctors need to tease out the causes of the mood swings.

The majority of children and adults with ADHD report some kind of sleep challenge — from racing thoughts at bedtime to restless limbs at night to tortured wake-up rituals every morning. Typically, these sleep disturbances are due to their energetic mix of hyperactivity, lack of focus, and, in some cases, stimulant medications. But insomnia doesn’t always mean ADHD, and other sleep disorders can mimic ADHD symptoms during daylight hours. Sleep apnea is a common culprit that's often misdiagnosed as ADHD — and vice versa. Fortunately, researchers are devising simple tests to definitively diagnose and get kids the treatment they need.

[Take This Self-Test: Could I Have ADHD?]

When children fail to complete and hand in schoolwork, parents and teachers may first assume ADHD is to blame. But problems in school can suggest a large number of conditions, including learning disorders, anxiety, or obsessive-compulsive disorder. When a child presents academic difficulties — and especially if they don’t respond to a round of ADHD medication — it’s important to consider other possible causes.

Clinical depression is common in adults with ADHD — experts estimate that depression exists in approximately 47 percent of adults with ADHD and  14 percent of children with ADHD — but depressive symptoms don’t always indicate a full-blown comorbid condition. Chronic difficulties caused by ADHD can lead to secondary depression, that is depression triggered by the frustration of coping with symptoms of ADHD, especially if the ADHD is untreated. If you’re feeling blue, losing energy, and no longer interested in things you used to enjoy, it’s important to take note of when it started and any possible causes, and to pursue a diagnosis to determine if its primary or secondary to ADHD.

About 40 percent of children with ADHD also develop oppositional defiant disorder (ODD). But not all oppositional behavior is indicative of a disorder, and a kid who is labeled “defiant” may be anything but. Some children resort to defiant behavior to cover up anxiety, and other children who appear “defiant” are actually just impulsive. This is another case where it’s important for doctors to tease out the root cause of the behavior — and not be so quick to label it ODD.

When a patient complains of excessive worry, physicians look to anxiety disorder — and with good reason. Anxiety has passed depression as the biggest mental health problem on college campuses. But anxiety doesn’t often stand alone — it is a hallmark symptom of ADHD, too, affecting 30 percent of children and 53 percent of adults with ADHD. If a child is constantly struggling due to untreated ADHD, for example, he may start to appear “on-edge” in previously tolerable situations. If your child starts feeling suddenly anxious, explore all causes — it could be a manifestation of ADHD.

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Experts estimate that children with ADHD are as much as 30 percent behind their peers developmentally — meaning a 10-year-old may act more like he's 7. But developmental delays and immaturity aren’t always related to ADHD — they can point to autism, anxiety disorders, or even sensory processing issues.

Children with inattentive type ADHD are often caught staring out the window or doodling when they should be doing math. Some daydreamers do have ADHD, but distraction is also a common symptom of OCD, for example. The difference? Kids with ADHD report being distracted by happy thoughts, like a recent sports victory. Children with OCD, on the other hand, get preoccupied with distressing obsessions, which stop them from shifting their thoughts and focus to where they need to go.

Trouble reading social cues and acting appropriately in social situations are hallmark symptoms of autism spectrum disorder (ASD). With autism rates on the rise, parents may fear the worst when their child struggles socially. But this is a big one for children with ADHD, too — though it usually isn’t considered until a diagnosis has already been made. If your child has trouble making friends, ask yourself: Is it because he's overly fixated on an unusual interest? Or is it because he's always interrupting and speaking over others? The former may be due to ASD; the latter, ADHD. An individual can have both conditions. Studies show that 30 to 50% of individuals with autism manifest ADHD symptoms; roughly two-thirds of individuals with ADHD show features of autism.

People with ADHD have notoriously poor working memory, which results in lost glasses, forgotten names, and blank-outs during tests. However, learning disabilities may also be a contributing factor to memory problems, as can another surprising cause: hypertension. In adults, high blood pressure is associated with several executive function deficits, particularly working memory. Even adults with ADHD may find they can improve their working memory by getting their blood pressure under control.

[Self-Test: Do You Have a Working Memory Deficit?]