Selective mutism is a form of abnormal behaviour in which the child who has already learned to speak and speaks in some social settings as other children do, but consistently fails to speak in certain settings, such as at daycare or school.
The aetiology of the disorder is considered multifactorial. Hereditary and environmental factors, temperamental features, anxiety tendency as well as developmental disturbances predispose a child to selective mutism. Bilingualism and multilingualism as well as immigrant background increase the risk of selective mutism.
Relatives of selectively mute children more commonly have psychiatric disorders, especially anxiety disorders than individuals in the general population.
The symptom picture often appears already in daycare age. Selective mutism of long duration is difficult to manage and therefore early intervening is important.
Epidemiology
The prevalence of selective mutism has been estimated to be at 0.2-1.9%. It typically starts before the age of 5 and is often noticed when the child starts day care or school.
Symptoms
Consistently not speaking at all or speaking only with few words in specific setting(s) is typical.
The child usually speaks at home, but does not speak outside home. Reverse situations are rare. The child's speaking is affected by those present (identity and number of persons) and by their ability to hear him/her speaking.
The disturbance usually begins gradually and is often noticed when the child starts at a day care centre or at school. In these situations, the diagnosis should not be established within the first month.
Approximately 70% of children also have other psychological and/or developmental problems. Anxiety symptoms, especially social anxiety and separation anxiety are common, as are language and speech difficulties. In these children, also enuresis, encopresis, and difficulties in activity and attention control are more frequent than average. Selective mutism also occurs in children with an autistic spectrum disorder.
Treatment
Children with selective mutism need psychiatric assessment.
The treatment is based on the comprehensive assessment that addresses both primary and comorbid problems.
Various approaches in the treatment of selective mutism like for example family therapy, play therapy, behavioural therapy, speech therapy and group therapy have been adopted.
Currently behaviour modification and other cognitive methods, together with cooperation with the family and the school or day care personnel, are recommended.
Selective serotonin reuptake inhibitors, especially fluoxetine, have been reported to be helpful when treating selectively mute children. At the moment, pharmacotherapy cannot be recommended as the treatment of first choice but if other methods of treatment are not effective, medication can be included in the treatment scheme. These drugs, however, do not have an official approval for paediatric use in the treatment of selective mutism.
Even after successful treatment, the child will probably continue to be apt to suffer from symptoms of anxiety and be reticent in certain situations.
References
Rozenek EB, Orlof W, Nowicka ZM, et al. Selective mutism - an overview of the condition and etiology: is the absence of speech just the tip of the iceberg? Psychiatr Pol 2020;54(2):333-349. [PubMed]
Koskela M, Chudal R, Luntamo T, et al. The impact of parental psychopathology and sociodemographic factors in selective mutism - a nationwide population-based study. BMC Psychiatry 2020;20(1):221. [PubMed]
Muris P, Ollendick TH. Children Who are Anxious in Silence: A Review on Selective Mutism, the New Anxiety Disorder in DSM-5. Clin Child Fam Psychol Rev 2015;18(2):151-69. [PubMed]