I deliberated for quite a while as to whether or not I should write this post on the back of the findings reported by Liliana Dell’Osso and colleagues  detailing the experiences of a "25-year-old man with a diagnosis of delusional disorder, erotomanic type" who was hospitalised when presenting with psychotic symptoms "in the framework of a repeated stalking behavior towards his ex girlfriend." Said man was assessed for "adult autism spectrum symptoms" via the Ritvo Autism and Asperger Diagnostic Scale (RAADS-14) and came out with something approaching autism spectrum symptoms.
My blogging hesitancy was in the most part due to the risk of stigmatising and generalising on the basis of the words 'stalking' and 'autism' appearing in the same sentence even in the context of a case report and not necessarily including a formal diagnosis of autism. I'd like to make it very clear that this is/was not my intention at all. As in previous occasions when science has been covered on this blog that falls into a slightly uncomfortable area (see here and see here) I did however eventually choose to cover this topic on the basis that [peer-reviewed] science is science irrespective of particular emotions around topics.
Stalking - the unwanted or obsessive attention by an individual or group toward another person - is a life-changing experience that has profound effects on its victims. The precise hows and whys of stalking behaviour are still the topic of discussion, although thought to be variably mediated by social and personal factors potentially combining with other, more neurobiological processes . As per the description provided in that last sentence and the use of the word 'obsessive' one might be able to see how such fixative behaviours might 'overlap' with some of the clinical description of autism or 'nearly autism' and particularly the idea that obsessions and compulsions might not be totally unfamiliar to the spectrum  including those around certain people.
I first came across discussions about stalking and the autism spectrum following my reading of the excellent overview by Tom Berney  (open-access). Describing the possible forensic presentation of Asperger syndrome, Dr Berney talked about "Overriding obsessions [that] can lead to offences such as stalking... Admonition can increase anxiety and consequently a ruminative thinking of the unthinkable that increases the likelihood of action." Anxiety and rumination, I might add, are areas crying out for more focused research with autism in mind (see here).
Other more experimental work looking at stalking in the context of autism has pointed to the possibility of an increased risk of such behaviours as per the findings reported by Stokes and colleagues . They reported that individuals with autism were "more likely to engage in inappropriate courting behaviours... and were more likely to focus their attention upon celebrities, strangers, colleagues, and ex-partners... and to pursue their target longer than controls." All this is set in the context of researcher reporting on a small participant group and being based on parental reports.
Insofar as the possible basis for stalking behaviours and the autism spectrum, the paper from Haskins & Silva  offers several opinions external to the involvement of obsessionality centred around the idea that empathy and perspective-taking abilities may also play a role. I'm not exactly a great fan of the exclusivity of concepts such as a lack of Theory of Mind (ToM) when applied to the autism spectrum (see here) but can see the logic in this assumption linked to stalking behaviours. Indeed, with such ideas in mind, the paper from Post et al  on possible strategies to prevent and overcome stalking when coincidental to autism make some sense.
Just before I bring this post to a close I'd also like to comment on the idea that psychosis or psychotic behaviour might also be an important part of any link between stalking behaviour and autism. Regular readers of this blog might already know that whilst not necessarily a mainstream opinion, I do perhaps think that autism research was historically a little hasty in burning all the bridges between autism and schizophrenia (see here) particularly when it came to the work of people such as Mildred Creak and colleagues. Science is beginning to recognise that a diagnosis of autism is in no way protective against the development of psychosis (see here) and preferential regular screening might be indicated.
Analysing the possibility of a relationship between stalking behaviour, autistic traits and psychosis sounds like something that might provide some important answers particularly in the context of the recent findings from Ho and colleagues  talking about ToM potentially being a trait marker of schizophrenia. Again treading carefully not to stigmatise or generalise, any moves to decreasing the likelihood and impact of stalking behaviour and the often devastating consequences that it can bring should be welcomed.
 Dell'Osso L. et al. Unexpected subthreshold autism spectrum in a 25-year-old male stalker hospitalized for delusional disorder: a case report. Compr Psychiatry. 2015 Apr 14. pii: S0010-440X(15)00054-1.
 Marazziti D. et al. Stalking: a neurobiological perspective. Riv Psichiatr. 2015 Jan-Feb;50(1):12-8.
 Russell AJ. et al. Obsessions and compulsions in Asperger syndrome and high-functioning autism. Br J Psychiatry. 2005 Jun;186:525-8.
 Berney T. Asperger syndrome from childhood into adulthood. Advances in Psychiatric Treatment. Aug 2004, 10 (5) 341-351.
 Stokes M. et al. Stalking, and social and romantic functioning among adolescents and adults with autism spectrum disorder. J Autism Dev Disord. 2007 Nov;37(10):1969-86.
 Haskins BG. & Silva JA. Asperger's disorder and criminal behavior: forensic-psychiatric considerations. J Am Acad Psychiatry Law. 2006;34(3):374-84.
 Post M. et al. Understanding stalking behaviors by individuals with Autism Spectrum Disorders and recommended prevention strategies for school settings. J Autism Dev Disord. 2014 Nov;44(11):2698-706.
 Ho KKY. et al. Theory of mind impairments in patients with first-episode schizophrenia and their unaffected siblings. Schizophrenia Res. 2015. June 3.
Dell’Osso, L., Dalle Luche, R., Cerliani, C., Bertelloni, C., Gesi, C., & Carmassi, C. (2015). Unexpected subthreshold autism spectrum in a 25-year-old male stalker hospitalized for delusional disorder: a case report Comprehensive Psychiatry DOI: 10.1016/j.comppsych.2015.04.003