By Alycia Halladay, PhD
ASF Chief Science Officer
If you missed it, on Tuesday the workgroup on Under-Recognized Co-Occurring Conditions in ASD of the Interagency Autism Coordinating Committee met to discuss the current issues and start to lie out a research agenda. This workshop was aimed to have an honest exchange of views to help direct research – the IACC does not directly fund research itself. It’s a way for researchers and funding agencies to discuss priorities and opportunities. The meeting was webcast live and will be archived on the NIH webpage, when the link is live we’ll post it. In the meantime here is what was discussed.
From the very first set of presentations it was clear that this issue is, like everything else is autism, complicated and messy. Four different presenters using different datasets all showed consistent findings of an increase in neurological (seizure), gastroenterological (GI distress) and psychiatric (ADHD and anxiety) comorbidities in ASD. The designs ranged from parent report, to pediatric registries, to health records that spanned through adulthood, to claims data from a number of different databases. And amazingly, while they actual numbers may be different, the trends in the data are the same. Many researchers pointed out that variability in the numbers could be because diagnostic practices – and that they could be under recognized or misdiagnosed.
Unfortunately, in the past these symptoms have not been well addressed by clinicians or even researchers. They are sometimes the most distressing and in the case of seizures, medically challenging. Sadly these comorbid problems can make ASD symptoms worse. Dan Coury gave the example of sleep – if you don’t get good night’s sleep, your “daytime” behavior changes. Beth Malow pointed out that in a brain of someone with ASD that is wired differently, sleep depravation causes even greater emotional problems. Larry Scahill from Emory presented on triggers for anxiety in people with ASD. These include peer relationships, different sensory stimulation. They are typically different than in typically developing people and the way people with autism express anxiety is different. Multiple co occurring conditions can mean multiple medications, which can lead to even more co occurring conditions. For example, some antipsychotics, used for impulsivity and aggression in ASD has been linked to obesity. Treating one symptom may cause another condition, which may be why people with co-ocurring medical conditions take on average, 5 different medications.
Another co-occuring symptom that is seen in a subgroup is immune dysregulation. Some individuals with ASD have an either overacting or underresponsive immune system, leading to anything from allergies to some GI problems. This means their immune systems react too much, or not enough, when faced with a normal challenge. A group at UC Davis linked to a particular part of the immune system to increased self-injurious and highly repetitive behaviors, and in one study, regression.
One of the presenters, Isaac Kohane from Harvard performed some statistical tools to identify subgroups using one of the large datasets mentioned earlier. For example, those that had seizures almost every day, or those that suffered from persistent infections including ear infections. He suggested that these subgroups might be meaningful in terms of treatment approaches, and even to understand the disorder better.
So what kind of treatments are we talking about? The overarching goal is to treat the co-ocurring condition to improve ASD symptoms. But right now, we aren’t even sure that the current treatments for these conditions are appropriate for those in ASD.
At the end of the meeting, we come back to the question – are these “co-occurring” conditions that are different entities or actually part of ASD itself? Evidence from genetics shows overlap between genes linked to ASD, ID, OCD and anxiety. Is it possible that these “co-occurring” conditions may all result from the same underlying mechanism, and therefore co-occurring and core symptoms of ASD are responsive to similar treatments? Scientists have been searching for a very long time for a biological mechanism that can separate out different “types” of autism and it hasn’t happened yet. Maybe it is time to take a different approach – and maybe this is the right way to go.
