Overlapping Symptoms of Bipolar Disorder in Children and Adolescents with Autism Spectrum Disorder

Background:  ASD is a developmental disorder arising in early years, whereas BD is primarily a cyclic affective disorder it is estimated that 1 in 68 children have ASD. The prevalence of ASD has risen significantly leading to increased awareness and research.  Research indicates an increased prevalence of psychiatric comorbidities in autism. However, there is limited research on the overlapping symptoms of conditions similar to ASD that may be confounding accurate diagnoses.  In BD and ASD, there are numerous symptoms that have significant overlap, especially when diagnosed during childhood. Some studies have been done on the prevalence of the BD and ASD and their correlation but the conclusions are conflicting and no clear results are available.

Objectives:  The objective of the study is to compare the clinical characteristics of Bipolar Disorder (BD) and Autism Spectrum Disorder (ASD).  Children diagnosed with ASD often have mood lability, aggression and sleep disturbances. Thus, whether these presentations are an entirely separate entity or characteristics of ASD itself raises a question of the extent of the overlap of symptoms and its diagnostic significance.  

Methods:  Data was analyzed from 100 CYASD diagnosed with autism during the calendar year 2012-2013. All patients analyzed received diagnosis and care at an Autism Speaks Autism Treatment Network Center of Excellence, affiliated with an academic medical center. Demographic information and specific variables were analyzed including age of diagnosis, delays in social skills and communication, presence of repetitive behavior, restricted interests, sensory issues, aggression, mood lability, depression, mania, thought disorder, family history of BD, ASD or disorders, toilet training, pregnancy and IQ. The criteria for assessing mood lability was the presence of emotional dysregulation in the form of temper tantrums, difficulty with transitions, rigid behaviors, easy irritability, internalizing and externalizing behaviors.

Results:  In our study, 50% of individuals had aggressive behavior, 95% had mood lability, 66 % had sleep disruptions and 5% of the children had depression but none of them had been diagnosed with classic mania, hypomania, hallucinations or thought disorder. 31% had family histories of BD and 29% had family histories of ASD

Conclusions:  In our study, half of our patients had aggression, one third had sleep disruptions and 95% had symptoms of mood lability. Pediatric bipolar disorder seldom presents with classic cyclic symptoms of mania and depression and more often presents with mixed features and rapid cycling. These symptoms are similar to those that can be seen in pediatric bipolar disorder and may predispose them to over diagnosis of BD.  Whether these presentations are a separate BD or characteristics of ASD is an area of controversy and scientific debate. Further investigation of patients with co-morbid ASD and bipolar disorder is needed on a larger scale to determine this. Current treatment of these two disorders differs greatly. This emphasizes the importance of prompt recognition and an accurate early diagnosis, which would allow for better, more economical, and more efficient outcomes benefiting both the physician and the patient.