Children are readily diagnosed with ADHD due to sleeping troubles, careless mistakes, fidgeting, or forgetfulness. The Centers for Disease Control and Prevention cite ADHD as the most commonly diagnosed behavioral disorder in children under 18.

However, many medical conditions in children can mirror ADHD symptoms, which makes correct diagnosis difficult. Rather than jump to conclusions, it’s important to consider alternative explanations to ensure accurate treatment.

The most difficult differential diagnosis to make is between ADHD and bipolar mood disorder. These two conditions are often hard to distinguish because they share several symptoms, including:

  • mood instability
  • outbursts
  • restlessness
  • talkativeness
  • impatience

ADHD is characterized primarily by inattention, distractibility, impulsivity, or physical restlessness. Bipolar disorder causes exaggerated shifts in mood, energy, thinking, and behavior, from manic highs to extreme, depressive lows. While bipolar disorder is primarily a mood disorder, ADHD affects attention and behavior.


There are many distinct differences between ADHD and bipolar disorder, but they are subtle and may go unnoticed. ADHD is a lifelong condition, generally beginning before age 12, while bipolar disorder tends to develop later, after age 18 (although some cases may be diagnosed earlier).

ADHD is chronic, while bipolar disorder is usually episodic, and can remain hidden for periods between episodes of mania or depression. Children with ADHD may experience difficulty with sensory overstimulation, like transitions from one activity to the next, while children with bipolar disorder typically respond to disciplinary actions and conflict with authority figures. Depression, irritability, and memory loss are common after a symptomatic period of their bipolar disorder, while children with ADHD do not generally experience similar symptoms.


The moods of someone with ADHD approach suddenly and can dissipate quickly, often within 20 to 30 minutes. But the mood shifts of bipolar disorder last longer. A major depressive episode must last for two weeks to meet the diagnostic criteria, while a manic episode must last at least one week with the symptoms present for most of the day nearly every day (the duration may be less if symptoms become so severe that hospitalization becomes necessary). Hypomanic symptoms only need to last four days. Children with bipolar disorder appear to display ADHD symptoms during their manic phases, such as restlessness, trouble sleeping, and hyperactivity.

During their depressed phases, symptoms such as lack of focus, lethargy, and inattention can also mirror those of ADHD. However, children with bipolar disorder may experience difficulty falling asleep or may sleep too much. Children with ADHD tend to wake up quickly and become alert immediately. They may have trouble falling asleep, but can usually manage to sleep through the night without interruption.


The misbehavior of children with ADHD and children with bipolar disorder is usually accidental. Ignoring authority figures, running into things, and making messes is often the result of inattentiveness, but may also be a result of a manic episode.

Children with bipolar disorder may engage in dangerous behavior. They may demonstrate grandiose thinking, taking up projects that they clearly cannot complete at their age and developmental level.

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Only a mental health professional can accurately differentiate between ADHD and bipolar disorder. If your child is diagnosed with bipolar disorder, primary treatment includes psycho-stimulant and antidepressant medications, individual or group therapy, and tailored education and support. Medications may need to be combined or frequently changed to continue to produce beneficial results.

Children with autism spectrum disorders often appear detached from their environments and may struggle with social interactions. In some cases, the behavior of autistic children may mimic the hyperactivity and social development issues common in ADHD patients. Other behaviors may include emotional immaturity which may also be seen with ADHD. Social skills and the ability to learn may be inhibited in children with both conditions, which can cause issues in school and at home.

Something as innocent as low blood sugar (hypoglycemia) can also mimic the symptoms of ADHD. Hypoglycemia in children may cause uncharacteristic aggression, hyperactivity, the inability to sit still, and the inability to concentrate.

Sensory processing disorders (SPD) can produce symptoms similar to ADHD. These disorders are marked by under- or oversensitivity to:

  • touch
  • movement
  • body position
  • sound
  • taste
  • sight
  • smell

Children with SPD may be sensitive to a certain fabric, may fluctuate from one activity to the next, and may be accident-prone or have difficulty paying attention, especially if they feel overwhelmed.

Children with ADHD may have difficulty calming down and falling asleep. However, some children who suffer from sleep disorders may display symptoms of ADHD during waking hours without actually having the disorder.

Lack of sleep causes difficulty concentrating, communicating, and following directions, and creates a decrease in short-term memory.

It may be difficult to diagnose hearing problems in young children who don’t know how to fully express themselves. Children with hearing impairments have a hard time paying attention because of their inability to hear properly.

Missing details of conversations may appear to be caused by the child’s lack of focus, when in fact they simply cannot follow along. Children with hearing problems may also have difficulty in social situations and have underdeveloped communication techniques.

Some children diagnosed with ADHD don’t suffer from any medical condition, but are simply normal, easily excitable, or bored. According to research published in the Canadian Medical Association Journal, the age of a child relative to their peers has been shown to influence a teacher’s perception of whether or not they have ADHD.

Children who are young for their grade levels may receive an inaccurate diagnosis because teachers mistake their normal immaturity for ADHD. Children who, in fact, have higher levels of intelligence than their peers may also be misdiagnosed because they grow bored in classes that they feel are too easy.