Racing Thoughts as a Symptom of ADHD

If you ever feel like your mind is taking you on a ride you can barely keep up with, or like new thoughts are popping into your head faster than you can process them, you might be experiencing what psychologists call racing thoughts.

Racing thoughts have long been known to be symptom of manic episodes in bipolar disorder, but new research suggests they can be a sign of ADHD as well.

In a study published in the journal Psychiatry Research, researchers investigated the phenomenon of racing thoughts in people with ADHD, people with bipolar disorder, and people with both.

They did so by administering a survey called the Racing and Crowded Thoughts Questionnaire, which measures – well, pretty much what the name says. It asks people whether they agree with statements such as:

• There is not enough time to grasp the meaning of a thought, as new ones immediately arise.
• My thoughts take off on their own
• I have too many thoughts at the same time

Using this survey to measure racing thoughts, the researchers found that ADHD was associated with racing thoughts. In fact, people with ADHD reported higher levels of racing thoughts than people with bipolar disorder who were experiencing hypomanic episodes.

Among people with ADHD, racing thoughts were frequently accompanied by anxiety. Whether people had ADHD by itself or both ADHD and bipolar disorder, racing thoughts tended to become more prominent in the evening and were linked to insomnia. Imagine trying to fall asleep while a relentless parade of thoughts flies through your mind, and you can see why the link with insomnia makes sense!

These findings led the researchers to conclude that “self-reported racing thoughts are a neglected but an intrinsic feature of adult ADHD.”

As an ADHD symptom, racing thoughts are neglected because symptom questionnaires like the DSM often don’t ask about racing thoughts.

Yet they seem to be an intrinsic symptom not only because they’re common in adult ADHD but because they could have a direct relationship with other core symptoms like distractibility and hyperactivity. In fact, the authors of the study frame racing thoughts as a kind of internal hyperactivity, which led them to title their paper Beyond motor hyperactivity: Racing thoughts are an integral symptom of adult attention deficit hyperactivity disorder.

That also means that racing thoughts can’t necessarily be used to distinguish between symptoms of bipolar disorder and symptoms of ADHD.

Adults with ADHD are sometimes misdiagnosed as having bipolar disorder because ADHD symptoms such as hyperactivity and impulsivity can appear similar to some symptoms of bipolar disorder. Even though racing thoughts are a classic symptom of manic episodes, the new research suggests that racing thoughts by themselves don’t tilt the scales toward a diagnosis of bipolar disorder since they may be a common ADHD symptom as well. As the researchers who conducted the new study write, racing thoughts “cannot differentiate ADHD and BD.”

For people with ADHD, the conclusions of this study may fit with their subjective experience. After all, people who experience the hyperactive side of ADHD do things too fast – they rush through things, or their brain plows ahead in an unexpected new direction.

The new study adds some empirical confirmation that the “rushing ahead” part of ADHD extends to racing thoughts, and it sets the stage for future research to learn more about this aspect of ADHD.