Prevalence of Autism Spectrum Conditions in a Youth Mental Health Service

Abstract

Andrew Thompson,, Orygen Youth Health Research Centre, Centre for Youth Mental Health, University of Melbourne, Melbourne, Victoria, Australia: Recent estimates regarding prevalence of Autism Spectrum Conditions (ASCs) in community samples range between 1 and 1.5 per 100 [1]. ASCs are associated with increased rates of comorbid psychiatric disorders including depression, anxiety disorders and obsessive compulsive disorder [2]. The main diagnostic and treat-ment issues in those presenting with ASC and psychiatric comorbidity are non-recognition of an existing ASC and misdiagnosis of an ASC occurring with another disorder such as psychosis [3]. Both non-recognition and misdi-agnosis are likely to signifi cantly impair treatment and delay recovery. At Orygen Youth Health, a mental health service for 15 to 25 year olds in Melbourne, Australia, we conducted an audit of all current cases in November 2007 to ascer-tain the prevalence of ASCs within the service. Treating clinicians were interviewed using a specifi c audit tool to determine whether any of the clients on their caseloads had an existing formal diagnosis of ASC or appeared to meet DSM-IV criteria for an ASC. The interview was pre-ceded by three local professional development sessions on diagnosis, treatment and comorbidity of mental illness and ASC provided by the study lead author (R.F.). Infor mation on ASC status was obtained for 476 of the 523 current patients. A total of 3.4% (n 16) had a con- fi rmed diagnosis of ASC and 7.8% (n 37) w ere reported by case managers to have a possible ASC diagnosis. A total of 3.4% (n 10) of those with psychotic disorders and 4.1% (n 5) of those with mood and anxiety disorders had a confi rmed diagnosis of ASC. There was no relationship between ASC status and gender χ (2) 2.91, p 0.233, ho wever there was a signifi cant difference between the three groups with respect to age, F(2, 473) 7.78, p 0.001, with post hoc anal yses (using Games-Howell test) revealing that those with a confi rmed diagnosis of ASC were signifi cantly younger on average than those with either possible ASC (p 0.002) or no ASC (p 0.001). It is interesting that this audit did not fi nd a gender difference in those with ASC as it is generally agreed that there is a 4:1 male female ratio [4]. This may be because there was a female predominance in this clinical sample. Those with a confi rmed ASC diagnosis were younger than those without in this sample, which may represent the additional impact of having an ASC as well as psychiatric illness. These results raise some impor tant issues for clinicians, service developers and commissioners. There are consid-erably higher rates of confi rmed ASCs within this clinical service compared to community settings, with the possi-bility that there are also additional undiagnosed cases. If these ASCs are not recognized it is unlikely that treat-ment will be optimal. Following this audit, and with sup-port from the Victorian Government, a developmental disorders clinic was established in Orygen Youth Health in 2009. It is hoped that through raising awareness of ASCs within youth and adult mental health settings that services might develop to provide expert treatment for a complex group of individuals who appear to be more prevalent than appreciated in such settings.