The title of this brief post reflects the findings reported by Efrosini Kalyva and colleagues  who undertook a review looking at the co-occurrence of autism spectrum disorder (ASD) and Tourette syndrome (TS) including the presence of tic disorder (part and parcel of the diagnosis of TS). The authors concluded that although the overlap rates might, to some degree, be tied into the "level of ASD severity" there may be quite a bit more to do research-wise to look at the hows and whys of the overlap.
I was not surprised to read such results. As per musings on this topic before on this blog (see here) tics - vocal or physical that can be both simple and complex - have been reported in about one in ten children and young adults diagnosed with ASD. Further: "Tic awareness is limited in ASD."  I might add that as and when autism appears with certain other comorbidities, the likelihood of tic disorder appearing jumps even further (see here).
Kalyva et al also suggested that anywhere between 4-20% of those with autism may also present with TS (reiterating the issue of 'level of ASD severity' as being a mediating factor). Again, one can only assume that such reporting should have implications for preferential screening where autism is diagnosed and onwards an appropriate assessment of the necessity of intervention (and not just of the pharmacological kind). I might also add that to talk about autism and TS appearing together does not necessarily mean that this reflects a homogeneous phenotype . The concept of 'autism plus'  marches on...
 Kalyva E. et al. A review of co-occurrence of autism spectrum disorder and Tourette syndrome. Research in Autism Spectrum Disorders. 2016; 24: 39-51.
 Kahl U. et al. Tic Phenomenology and Tic Awareness in Adults With Autism. Movement Disorders Clinical Practice. 2015. March 30.
 Zappella M. Early-onset Tourette syndrome with reversible autistic behaviour: a dysmaturational disorder. Eur Child Adolesc Psychiatry. 2002 Feb;11(1):18-23.
 Posserud M. et al. Autism traits: The importance of "co-morbid" problems for impairment and contact with services. Data from the Bergen Child Study. Res Dev Disabil. 2016 Jan 27. pii: S0891-4222(16)30002-6.
Kalyva, E., Kyriazi, M., Vargiami, E., & Zafeiriou, D. (2016). A review of co-occurrence of autism spectrum disorder and Tourette syndrome Research in Autism Spectrum Disorders, 24, 39-51 DOI: 10.1016/j.rasd.2016.01.007