Where possible assessment of SM should be sought via a Psychologist, Speech Pathologist and/or Occupational Therapist with experience in the area. When this is not possible, professionals can be pointed to websites and books with further information in this area (see useful links and readings section).
If you are concerned that a child is not initiating communication or is experiencing some level of speaking anxiety in any social situation then seek further assessment. The largest indicator is usually that the individual speaks freely in comfortable settings with familiar others but is silent in other settings such as school or when out of the home.
Below are links and/or descriptions of some of the assessment materials that i have found to be useful. As with all the resource sections please do get in contact if you would like to recommend others.
The Diagnostic and Statistical Manual of Mental Disorders (5th ed.; DSM–5; American Psychiatric Association, 2013).
This provides the diagnostic criteria for SM and should be used as the reference for any diagnosis by treating professionals.
The Selective Mutism Resource Manual (Johnson and Wintgens, 2002)
This book is my SM bible! I have found the following resources from the book particularly useful for assessment:
School Report Form
Talking Map (a useful visual strategy to support the individual to express who, where and when they experience speaking anxiety without the need for speech)
My Talking Rating Scale (for use with the child to rate therapy targets)
Stages of Confident Speaking (useful a tool for outcome measurement and demonstrating that not all children with SM are at the same stage)
Helping Your Child with Selective Mutism (McHolm, 2005)
I have used and ammended the items below to support identification of speaking rules and identify levels of anxiety throughout the day.
Speaking Situations Assessment Log
Comfort in Daily Activities Log
Selective Mutism-Stages of Social Communication Comfort Scale (SMart Centre) -
I have found this particularly useful for identifying differences between initiation and responding of communication and to support identification of wider anxieties. This handout from the same site
This handout gives a great explanation of the scale for teachers, parents and professionals alike.
Children with SM should ALWAYS have a communication assessment to identify/rule out difficulties with understanding or expression of language as a cause of the mutism. This can be achieved with non verbal use of many Speech Pathology assessments and receptive samples of language can sometimes be recorded by parents for later analysis from the Speech Pathologist.