At home, Alyssa Hoyle is just like any other three-year-old; chatty, boisterous, playful. But at school, and around others who are not her immediate family, Alyssa is silent. In fact, six months into nursery and no-one had even heard her voice.
"From about the age of two, she would quite happily babble at home around her siblings and me and her dad," Alyssa's mum Rosie says. "But she'd be mute if anyone came into the house, or if we were out in public."
Alyssa avoids eye contact, puts her hands in her mouth, and turns her back to anyone outside of her close family – even her grandparents, uncles and aunts.
"At home her speech developed fantastically," Rosie continues, "but anywhere she is expected to talk, such as nursery, causes her to have panic attacks. She'll be rocking in a corner, or lashing out.
"Even now, sometimes the anxiety is so bad that if she's spoken to unexpectedly she freezes and wets herself in fear."
Alyssa may sound like she just has a case of severe shyness, but she suffers from a condition called selective mutism (SM). Although relatively unheard of, SM is thought to affect around one in every 140 children.
It's a situational anxiety disorder, which can have "very long-term effects on a child's future mental health," according to Carl Sutton, founder of SM support organisation iSpeak.
The average age of the onset of SM is between two and four years of age, with the disorder first becoming apparent when a child enters a communal environment outside the family, for example, school.
For reasons unknown, SM appears to be more prevalent among girls and those from migrant and multi-lingual families, according to mental health charity Selective Mutism Information and Research Association (SMIRA).
Some of Alyssa's teachers and playmates have still never heard her voice, and mum Rosie says SM has prevented her daughter from making friends.
"She’s a very intelligent little girl who wants to play and have her own friends, but she's living in a world where she can't talk, and anxiety makes her world a tough one."
Those with SM tend to feel isolated and sometimes go unnoticed, says Lindsay Whittington, co-founder of SMIRA.
"The essential feature of SM is the persistent failure to speak in specific social situations, such as at school or with peers, despite being able to speak in other more familiar situations," Whittington says. "No single cause has been established, though emotional, psychological and social factors may influence its development. In the past these children were thought to be manipulative or angry, but research now points strongly to social anxiety, similar to stage fright.
"Some children with SM may also appear stubborn, but this is borne out of their need to control their anxiety levels, and some have a tendency to periods of aggression or tantrums in the home due to personal frustrations."
In some cases, SM can last well into adulthood, as with 35-year-old Sabrina Branwood, from Rochdale, who communicates via an app on her tablet.
"When people ask me questions, my anxiety makes it hard to think," she explained through her app. "Trapped. I'm not silent because I don't want to talk. I would rather talk freely but it's very difficult and complicated.
"Having selective mutism can feel like you're living your life in a box. The box is see-through so you can see out and hear people, but you can't leave no matter how hard you try."
There are numerous repercussions for children with SM who do not receive sufficient therapy.
"By adulthood, it's almost certain they will suffer from depression," says Sutton. "They are also significantly more likely to have any number of other anxiety disorders including social anxiety disorder, generalized anxiety disorder, agoraphobia, panic disorder and obsessive compulsive disorder."
By a child's teenage years, a "significant subset" will be unable to continue in mainstream education and will require home-schooling.
"Many young adults with SM are virtually housebound," Sutton adds. "Many cannot work. SM can thus be extremely disabling in terms of future prospects in life."
Early intervention is crucial to overcoming SM, as Felicity Whyte can attest.
Her son Dougal simply did not speak for the four days a week he spent at his childminder's house.
"She alerted us to her suspicion that Dougal may have SM and we worked to see if we could get him seen by a professional," Felicity recalls.
"While we were waiting for referrals we did a lot of reading on what a huge difference early intervention can make to outcomes.
"We made several changes in our lives to try and alleviate Dougal's anxiety before he started school - my husband changed his career so he could care for our son at home."
Dougal started school in September and, although shy, does communicate with the teacher and children. Felicity also wrote a letter for the nursery ahead of her son starting, to help the staff understand his condition.
"It's huge progress," says Felicity. "I want to share my story to show how much early identification can help. Many people don't understand the anxiety aspect of selective mutism, and many health professionals don’t understand the condition or its causes.
"It is so misunderstood as a speech issue, or a behavioural issue, when it truly is an anxiety issue which has a genuine physical manifestation."
Felicity and her husband had to self-fund the care for Dougal, but she says doing so has meant her son’s transition to school was considerably smoother.
"Waiting for standard available healthcare routes would have significantly delayed diagnosis and really impeded his chance of communicating at school."
Sutton says many people think SM only affects young children when in fact it affects a "significant number" of teens and adults too.
"At least 7% of children with SM become young adults with SM, equating to around one in 2,400 young adults," he says.
"There’s also a belief SM only occurs in school, whereas many affected children will be mute with extended relatives, strangers, step-parents and so on. And, though quite rarely, some will be mute with their own birth parents – as I was."
Whittington adds: "There may be a lot of children out there whose parents think they are just shy, but selective mutism is more than just normal shyness.
SM is often mistaken for "normal shyness", says Whittington; a mistake teachers made with three-year-old Melanie Radcliffe. Melanie was a "normal, chatty toddler" who showed no signs of suffering from SM until starting nursery.
"She made a friend who she chatted to, albeit very quietly," Melanie's mother Sue explains. "It was eventually flagged up to me that my daughter was not speaking to her peers, other than her friend. Teachers seemed to think she was shy and that she would grow out of it."
Only she didn't.
Despite being confident at home, Melanie reached nine years old without speaking to anyone else apart from her one friend.
"It was really starting to concern me," recalls Sue. "It was only when I watched a TV programme featuring a little girl exactly like Melanie that I had a light bulb moment."
SM may become more apparent as the child reaches school age, where "hopefully" it is picked up by teaching staff, says Whittington.
"There may be a lot of children out there whose parents think they are just shy, but selective mutism is more than just normal shyness. Anyone who is concerned that their young child may be selectively mute should discuss their fears with either the school, their Health Visitor or GP."
Melanie was eventually referred to the Child and Adolescent Mental Health Services (CAMHS), where she was treated by therapists.
"From the day my daughter was diagnosed little did I know how difficult our journey would be," Sue adds.
"Because Melanie was not diagnosed at an early age, a lot of her SM behaviour had become entrenched, which in turn led to further mental health problems including self-harming and depression.
"It certainly has been a tough couple of years, but although her SM is still very much present she seems to be coping a lot better."
SM is by no means a "life sentence", adds Sutton. "With appropriate support, people can live fulfilled adult lives and reach their full potential."
Linda Lloyd's daughter is one such success story. At just three years old, Jennie was diagnosed as deaf.
"Everyone thought her silence was a characteristic of her hearing problem, but as time went on we realised it was more than that," she says.
After trying to cope with the problem for years, Linda eventually found help for Jennie, who was put on a programme to try and overcome her condition.
"Our daughter eventually came out of her silence aged 16 – after more than a decade of silence.
"She's now a very happy young woman of 33, a mum, and getting married next year.
"It took a long time and an awful lot of patience, but we’re so proud of everything our daughter has achieved."
- SM usually occurs in early childhood, when the child begins to interact outside the family circle
- They may seem awkward, clingy, serious or nervous
- It's not clear what causes some children to develop SM, although it is associated with anxiety
- If left untreated, SM can lead to isolation, low self-esteem and social anxiety disorder, and persist into adulthood
- With diagnosis and appropriate treatment, children can successfully overcome this disorder