3 common ADHD symptoms that might actually be something else, according to a psychologist

Many broad ADHD symptoms like distractibility or impulsiveness also exist in other disorders like autism, borderline personality disorder, and PTSD.

• A psychologist said that some common ADHD symptoms may not actually be due to ADHD.
• Inattentiveness, hyperactivity, and impulsivity can all be symptoms of other disorders. 
• Autism, depression, and BPD can all have overlapping symptoms with ADHD.

While ADHD consists of a wide array of symptoms, some of the most commonly talked-about ones include struggling to focus and jumping from task to task.

But going off those broad symptoms alone can lead to a misdiagnosis — especially if you're solely relying on what you read online.

Dr. Lara Honos-Webb, a clinical psychologist specializing in ADHD, previously told Insider that one of the most important aspects of ADHD is that you've displayed symptoms since childhood. Otherwise, it's hard to know if symptoms like inattentiveness or hyperactivity are truly from ADHD, or if they're from other psychological or neurological disorders.

It's one of the reasons she suggests getting a formal ADHD diagnosis from a medical professional, who can help establish whether you've had symptoms for years, or if they're a more recent development.

"That's why a symptom checklist for ADHD is problematic," she told Insider, noting the popularity of Instagram infographics and quick online ADHD quizzes.

Honos-Webb spoke to Insider about three common signs of ADHD that can overlap with other disorders, leading to a potential misdiagnosis or incomplete diagnosis.

Inattentiveness

One of the biggest symptoms of ADHD is distractibility or inattentiveness — something Honos-Webb said isn't actually unique to ADHD.

"There are many diagnoses that have 'difficulty concentrating' as a symptom," she said.

For example, an autistic person may lose focus, but it could be the result of getting distracted if they're experiencing sensory issues or are struggling to mask.

She also said that having mood disorders, such as anxiety, depression, and bipolar disorder, often result in an inability to focus.

Or if someone has PTSD, she said, "you can imagine if you're being flooded with intrusive images that it comes with a difficulty concentrating because of the trauma."

Hyperactivity

Hyperactivity is another major symptom of ADHD, according to the DSM-5. In children under 16, it can look like running around a lot, getting up from their seat, or talking excessively.

But Honos-Webb said that hyperactivity is also a symptom of autism, and that people with bipolar disorder who experience manic symptoms can also appear hyperactive.

Impulsivity

Another ADHD symptom is impulsivity, which can overlap with other disorders like borderline personality disorder, Honos-Webb said.

The mood swings that people with BPD experience can resemble erratic or spontaneous behavior, but Honos-Webb said there are some differences between BPD and ADHD impulsivity.

She said "the reactivity of mood is key" to being diagnosed with BPD, and people with BPD also often experience deep depressive phases as well. She also said that BPD is "more of a relationship disorder" in that mood swings are more likely to be caused by attachment issues.

Honos-Webb said that it's also possible to have multiple disorders without realizing it. About 50-70% of people with autism also have ADHD, for example. And some patients who have ADHD may also have PTSD, which can exacerbate symptoms.

She said seeing a professional can give you a fuller idea of what your symptoms are and how to work with them.