OCD Ain't ADHD

OCD and ADHD are not the same and misdiagnoses could cause serious problems

/ Author:  / Reviewed by: Joseph V. Madia, MD

(RxWiki News) Millions of Americans have serious behavioral and attention issues. While attention deficit hyperactivity disorder (ADHD) may be to blame for many of these issues, another behavioral disorder could also be the culprit.

ADHD shares many symptoms with obsessive compulsive disorder (OCD). Patients with either condition have trouble paying attention, controlling behavior and logging things into memory. But the two conditions may have more differences than similarities.

Results from a recent study showed that both patients with ADHD and those with OCD had trouble controlling impulsive behavior in a laboratory setting.

However, only ADHD patients had trouble controlling those impulses in a real world setting.

Despite the similarities between these two conditions, these findings highlight a clear difference between ADHD and OCD. If a patient is wrongly diagnosed with one disorder instead of the other, treatment may do more harm than good.

"Get a ADHD diagnosis before receiving treatment."

Reuven Dar, PhD, of Tel Aviv University's School of Psychological Sciences, and colleagues set out to compare mental and behavioral issues between adults with OCD and adults with ADHD.

The study included 30 patients diagnosed with ADHD, 30 patients diagnosed with OCD and 30 people with no mental health diagnosis. All participants were men.

The researchers used mental health tests and questionnaires to measure participants' cognitive function (memory, attention and problem-solving) and control of impulsive behaviors.

Results showed that both patients with ADHD and those with OCD did not perform as well as those without mental disorders in terms of memory, attention and problem-solving. Both ADHD and OCD patients had trouble controlling impulsive behavior in a laboratory setting, but only ADHD patients had trouble controlling these impulses in a real world setting.

According to Dr. Dar, it's understandable that symptoms of OCD can be mistaken for those of ADHD. If a student seems restless and inattentive in the classroom, a teacher may think that student has ADHD. However, that student's restless and inattentive behavior could be the result of OCD, or obsessive thoughts or compulsive behaviors.

"It's more likely that a young student will be diagnosed with ADHD instead of OCD because teachers see so many people with attention problems and not many with OCD," said Dr. Dar in a press release.

"If you don't look carefully enough, you could make a mistake."

A wrong diagnosis could lead to the wrong treatment, which could spell real trouble for OCD patients diagnosed with ADHD.

For example, one of the most common ADHD medications - called Ritalin (methylphenidate) - can make OCD symptoms even worse.

In addition, patients who are incorrectly diagnosed may get the wrong psychological and behavioral treatment.

dailyRx recently spoke to Glen R. Elliott, PhD, MD, about this study. Dr. Elliott is a Clinical Professor (Affiliated) at the Stanford University Department of Psychiatry and Behavioral Sciences, Emeritus Professor of Clinical Psychiatry at the University of California, San Francisco, and Chief Psychiatrist and Medical Director at Children's Health Council, a not-for-profit child and adolescent mental health facility affiliated with Stanford.

"These results need to be viewed with caution, because the authors are mixing neurophysiological findings with cognitive measures that are not necessarily specific to either OCD or ADHD, so any assertions about common underlying brain systems are speculative, at best," said Dr. Elliott.

Still, Dr. Elliott discussed one of the main issues raised by the study: the diagnosis and misdiagnosis of ADHD.

"The gold standard for diagnosing ADHD, whether in younger individuals or adults, is a thorough history and assessment," he said. "Neither psychological testing nor available physiological measures have proven better, and this paper shows one of the reasons: potentially quite different disorders can present with seemingly similar behaviors or psychological test results. Thus, someone with anxiety or OCD might have problems with attention or impulsivity that, at least superficially, resemble those typical of ADHD. Studies have shown that ADHD is misdiagnosed, undiagnosed, and overdiagnosed depending on the specific setting and types of assessments used."

Dr. Elliott went on to point out that there is no one simple way to diagnose ADHD.

"There is no single step doctors must include in an assessment that guarantees an accurate diagnosis. The closest is the importance of assessing how symptoms have evolved over time," he explained. "We do not believe someone 'catches' ADHD; rather, it is a condition probably present from birth and infancy that eventually causes sufficient impairment in function to warrant a diagnosis. Those with high levels of impulsivity or hyperactivity or both tend to receive diagnoses relatively early, sometimes as preschoolers; those with mostly problems relating to attention and distractibility typically are diagnosed later, perhaps as late as age 10 or 11. That is not when they develop the disorder but rather when the disorder is preventing them from functioning in ways comparable to their peers."

Dr. Elliott also noted, "Adults and even teens suddenly showing behaviors suggestive of ADHD nearly always have some other condition whose symptoms overlap with those used to diagnosis ADHD."

The study by Dr. Dar and colleagues was published September 6, 2012 in the Journal of Neuropsychology. No funding or disclosure information was available.

Reviewed by: 
Review Date: 
February 4, 2013
Last Updated:
August 19, 2013