Individuals with bipolar disorder experience periods of hypomania, or manic behavior, and depression. "The individual cycles through these different episodes throughout the course of the year. If there are more than four cycles within a year, it is considered bipolar disorder," said Kimberly Frazier Baker, PhD, CCC-SLP, assistant professor of communication disorders at the University of Arkansas in Fayetteville.

Hypomania gives people a feeling of well-being. Individuals may feel overly productive, creative and confident. Because they get carried away with what they are doing, they may lose sleep. However, there is a breaking point. "The individual will become obsessed. They will no longer feel creative and start to feel aggravated, anxious and overwhelmed," said Baker. This letdown will give way to episodes of depression.

Perhaps the biggest obstacle in accurately diagnosing bipolar disorder as a co-morbid condition is the overlap in symptomatology. Children with Asperger's syndrome have difficulty interpreting social stimuli and obsess over a topic of interest. They have issues with executive function, theory of mind and central coherence, or understanding context. The symptom most commonly associated with Asperger's--the obsessive interest in a topic--is also a cornerstone of bipolar disorder.

"Individuals can get engrossed in a particular topic. This can be confused with the creativity that sets in during the hypomania phase of the bipolar person," said Baker. There is a difference, however. "The big difference between Asperger's and bipolar is the manic stage. Individuals with Asperger's will always want to talk about their topic. They may not have that aggravation or anxiety associated with it, whereas someone in the manic stage might."

Individuals with Asperger's want to have a relationship with other people and talk about their topic of interest, while someone who is bipolar doesn't want to be around others when they are depressed.

The anxiety expressed by an individual with Asperger's could also match that of someone who is bipolar. Or "they could have an anxiety disorder," said Baker. "That, coupled with Asperger's, can sometimes look a lot like bipolar. It's hard to determine which is which," she said.

Reliable statistics on how many children with Asperger's are diagnosed with bipolar disorder have yet to materialize, not to mention more on what the condition specifically looks like in this population. In addition, Asperger's is a relatively new diagnosis on the autism spectrum, and it took time for researchers and clinicians to reach the understanding they have about the condition today.

"We don't really have a good indication of what bipolar is in children," said Baker. "We know there is a high occurrence of depression and bipolar disorder in families of individuals on the autism spectrum. Both appear to be genetic-we see both of the conditions among families."

When is it apparent that a person with Asperger's could also have bipolar disorder? Clinicians should begin to suspect bipolar if individuals appear to be going through the hypomania-depression cycle. It may be time to act if they become highly distracted, self-injurious, withdraw from others, cry, become irritable or non-compliant, and have pressured speech.

Before jumping to conclusions, though, it's important to rule out other diagnoses. "Anxiety is one of the first things I would try to rule out before I thought, 'Are we looking more at anxiety coupled with Asperger's, or is it mainly just bipolar?' If you are seeing bouts of depression, you might want to start thinking about bipolar," Baker advised. A good rule of thumb is to wait a year for signs of cycling and to see if bipolar symptoms subside.

The presence of another disorder can have a significant impact on treatment, she said. "If an individual with bipolar is engaging in self-injurious behavior or being aggressive, you have to take care of that pharmacologically before cognitive behavior therapies will be effective."

Baker cited her current work with a young patient who has a mixed diagnosis of bipolar and Asperger's. "Now that the proper pharmacological interventions have been initiated, my interventions have really increased with him," she said. "To say he's a different child would be an understatement."

An important reminder is that if a clinician suspects a child has both bipolar and Asperger's, one condition should not take precedence over the other.

The prevalence of bipolar disorder in children with Asperger's is unknown, but clinicians who work with this population should be trained to spot the symptoms in order to make the proper recommendations and referrals, Baker said. Speech-language pathologists, pediatricians, psychologists, psychiatrists, occupational therapists, counselors, and special and regular education teachers are all part of the multidisciplinary team.

Jason Mosheim is an ADVANCE contributing editor.