Mya Allen, 3, refuses to go to bed on time and every night is a battle for her mother Rachael.

Strong personality … Rachael Allen with her daughter Mya. Photo: Wolter Peeters

Every night at 7.30 the battle begins. That's when Rachael Allen starts trying to get her daughter Mya, 3, into bed.

By the time she does, usually between 10.30 and 11, the family are exhausted. Mrs Allen has always attributed this behaviour to her daughter's strong personality. “It's like she doesn't want to miss anything," she said.

It's really based on irritability and irritability is a symptom. 

But changes to the way mental illness is diagnosed may mean children such as Mya could be diagnosed with insomnia, as childhood disorders are merged into adult ones. For the first time, insomnia will include child-specific symptoms under proposed changes to the Diagnostic and Statistical Manual of Mental Disorders, commonly known as the psychiatrist's bible, which is being updated this year.

Experts warn that children could be the victims of a new psychiatric epidemic if the proposals, which include creating new disorders, go ahead.

Disruptive mood dysregulation disorder, a new condition involving recurrent and severe temper outbursts in response to common stressful events, is the most controversial diagnosis proposed for inclusion.

Peter Parry, a child and adolescent psychiatrist and a senior lecturer at Flinders University, said DMDD might "gain the kind of notoriety of other acronyms like ADHD. It's really based on irritability and irritability is a symptom . . . in a lot of psychiatric disorders . . . and a lot of children.”

DMDD is being proposed for the manual as an alternative to childhood bipolar disorder, which has exploded as a diagnosis in the US but is less common elsewhere. Dr Parry's research found the rise was related more to the influence of the pharmaceutical industry, marketing direct to consumers and inequalities in the healthcare system than to the discovery of any new disease.

Dr Parry was concerned insomnia could be diagnosed in a child who persistently resisted going to bed. Such a diagnosis might not take account of other factors that could disturb sleep.

Mrs Allen said she had never considered her daughter might have insomnia. “I have just written it off in my mind as toddler behaviour. But I would hate for people to palm it off as a stage if it's causing harm. It doesn't really register as a problem until you think about it like this.”