Selective mutism and the anxiety spectrum--a long-term case report.

Financial support: None Conflict of interests: None Dear Editor, Selective mutism (SM) is a disorder characterized by inability to talk in specific situations, despite of being able to talk in familiar places. With a prevalence of 0.3%-1% in schoolage children,1,2 most cases (79%) start at preschool age and have transitory course.3,4 Psychotherapeutic interventions and selective serotonin reuptake inhibitors are considered first and second line treatments, respectively.1,5 We report a case of SM in a 17-year-old girl whose symptoms started when she was 4 years old and have persisted during adolescence. She stopped talking to everyone after a haircut. She panicked every time her mother went out or when she was left at school. She didn’t talk for 45 days, and then progressively recovered, talking first to her sisters, then to other relatives. One year later, she stopped talking again after her bike had been stolen. Three months later, she started to chat with relatives and two close friends. She hasn’t talked to anyone else since then. Despite this fact, she regularly goes to school and has friends of her age, with whom she communicates through e-mails and mimics. Neither academic nor cognitive impairment have been detected along all school years. She likes to dance and to play handball. When she needs something that requires talking, her mother does it on her behalf, which prevents her from being exposed and increases avoidance of anxiety situations. According to DSM-IV criteria, a diagnosis of SM was made. Assessed through a semi-structured interview (Schedule for affective disorders and schizophrenia for school-age children, K-SADS), she met diagnostic criteria for Separation Anxiety Disorder (in the past), current diagnosis of Specific Phobia. She didn’t have any other anxious (including social anxiety), affective or psychotic symptoms. Before her referral, she was treated with psychodynamic therapy and took paroxetine (20 mg/daily) for 12 months without improvement. At our service, she was treated with cognitivebehavioral therapy (CBT) for 10 months with poor outcome. Then, CBT was associated with sertraline (150 mg/daily). After 3 months, the level of anxiety on CBT exposures lowered. She started to shout when playing handball, she talks louder to her mother in public places, and talks to friends through lips movements. Though she isn’t talking to many people yet, she is clearly less anxious. There is some controversy whether SM is an anxiety disorder (AD) or an independent diagnosis. Previously, SM was considered an oppositional behavior, a psychotic symptom or a dissociative disorder. In DSM-IV, SM is classified under Other Disorders of Childhood. SM has many aspects in common with AD: premorbid temperament (shyness, behavioral inhibition), parent-child overdependence, overlapping diagnoses with other AD (social phobia, separation anxiety), and high prevalence of parents with AD.5 Some authors propose that SM is an extreme manifestation of social phobia.2 Our patient denied having social anxiety in situations that don’t involve talking, but other anxiety symptoms were observed, such as early manifestation of separation anxiety, supporting the hypothesis that SM should be considered an anxiety spectrum disorder. Although genetic, behavioral, psychodynamic and family factors must be considered, the etiology of SM remains unknown.1 The available options for clinical treatment are based on open-label studies, case reports and clinical experience.3,5 This case has shown a better outcome when biological and psychotherapy interventions were associated, which may indicate a field for future researches. Having SM as a subcategory of AD may benefit its comprehension, not only as a symptom, but as a unique disorder with its own characteristics.