I wanted to draw your attention to the paper by Greenlee and colleagues  today, talking about how: (a) "Co-occurring depression is a particularly common problem in higher-functioning older children" with autism, and (b) "children with ASD [autism spectrum disorder] and a history of a depression diagnosis are more likely to also have co-occurring medical problems" at least in their cohort.
Published as part of a supplement about autism in the journal Pediatrics (see here), the Greenlee paper describes findings based on the examination of over 1200 children and young adults diagnosed with an ASD derived from the "Autism Speaks Autism Treatment Network consortium." Looking at non-depressed (n=1183) and 'ever' depressed (n=89) parent or caregiver reports of offspring, researchers reported a few important details.
As per those non- and ever-depressed figures, the experience of depression or at least some of the symptoms of depression is not uncommon in paediatric autism. Drilling down into further detail, the authors reported that around a fifth of teens/young adults (13-17 years) were reported to have a history of depression. The added suggestion that "higher IQ, and Asperger disorder diagnosis" (authors words not mine) might be important correlates taps into other independent findings (see here).
And then something a little more new... "After controlling for age, IQ, and within-spectrum categorical diagnosis, the ever-depressed group exhibited significantly greater rates of seizure disorders... and gastrointestinal problems... and trend-level differences in aggression, somatic complaints, and social impairments. The groups did not differ in autism severity, repetitive behaviors, sleep problems, eating problems, self-injurious behavior, or current intervention use."
These are interesting findings despite the need for further replication and validation. That depression might also 'correlate' with somatic issues such as seizure disorders such as epilepsy or gut issues is something I'm particularly interested in. Outside of the idea that depression might not be entirely unexpected alongside the presentation of epilepsy for example (see here), the suggestion that bowel issues might also correlate in relation to autism, taps into some preliminary independent work previously covered on this blog (see here). I might also bring in some more general work looking at how labels such as depression have been noted to be over-represented when it comes to specific GI complaints such as irritable bowel syndrome (IBS) for example (see here) as further fodder for thought.
The nature of the relationship between autism, depression and something like bowel issues remains the stuff of speculation, particularly the question of what comes first. I might provide some ideas for future research directions with a view to the overlap with anxiety (see here) as a start. I could even suggest that further efforts might be needed to look into whether more external agents might play a role for some (see here) including those trillions of wee beasties that call us all home (see here). But this would only be speculation, and taking into account the plurality of autism (see here), science needs to do a lot more work on these important comorbidities, particularly given the heightened risk of adverse outcomes potentially linked to the experience of depression and how a relationship between autism and depression may even stretch into older age ...
 Greenlee JL. et al. Medical and Behavioral Correlates of Depression History in Children and Adolescents With Autism Spectrum Disorder. Pediatrics. 2016 Feb;137 Suppl 2:S105-14.
 Wallace GL. et al. Aging and autism spectrum disorder: Evidence from the broad autism phenotype. Autism Res. 2016 Mar 11.
Greenlee JL, Mosley AS, Shui AM, Veenstra-VanderWeele J, & Gotham KO (2016). Medical and Behavioral Correlates of Depression History in Children and Adolescents With Autism Spectrum Disorder. Pediatrics, 137 Suppl 2 PMID: 26908466