Like kids with ADHD, children with autism might not adjust to change very well, and high-stimulus environments might cause them to get overly excited, which can seem like the hyperactivity associated with ADHD. Both kids with autism and those with ADHD can have a hard time bonding emotionally and understanding social rules, making it tough for them to fit in and make friends. But kids with autism will have more difficulties communicating than a child with ADHD would because they find it hard to decipher nonverbal language like tone of voice, facial expressions, and body language. Read more about the differences between ADHD and autism here.
Bipolar mood disorder
Some experts estimate up to 85 percent of kids with bipolar mood disorder are also diagnosed with ADHD. During their “manic” phases, bipolar children could show symptoms like hyperactivity and sleeplessness, while their “depressed” phases could show symptoms like inattention and lack of focus—all of which are symptoms similar to ADHD. But ADHD is an ongoing condition that usually starts around age 7, while bipolar disorder is episodic. Misbehavior from kids with ADHD is usually an accident resulting from inattentiveness, while bipolar children might seek conflict on purpose.