It is essential that psychosis in children and teenagers is picked up as early as possible and treatment is implemented without delay, doctors have warned.

Psychosis refers to a mental state in which a person is detached from reality and experiences a number of abnormal symptoms such as hallucinations, delusions and incoherent thoughts. The most well known psychotic condition is probably schizophrenia.

According to Prof Fiona McNicholas, a consultant child psychiatrist at the Lucena Clinic in Dublin, and Trinity College medical student, Megan McNicholas, schizophrenia affects around 1% of the population.

The peak onset in males is earlier than in females - 15-25 years versus 25-35 years.

The doctors noted that while the condition is ‘very rare' in childhood, it becomes ‘increasingly more common after puberty'.

In fact, the prevalence of any psychotic disorder increases from less than one in every 10,000 children aged 13 to over 17 per 10,000 by the age of 19.

"In Ireland alone, schizophrenia accounted for 13% of all child and adolescent (psychiatric) admissions in 2011, 67% of which involved male patients," the doctors said.

They pointed out that the exact cause of schizophrenia is still unknown, but a number of factors are thought to play a role, including genetic, social and neurodevelopmental factors. Some illnesses and types of medication can also induce a psychotic state.

The doctors emphasised that young patients presenting with psychotic symptoms or behavioural changes, such as depression or anxiety, ‘should undergo a full medical and psychiatric assessment' by a doctor. This should include ‘a detailed clinical history from the young person and their parent, supplemented by information from school'.

"Initial assessment by a GP would typically be followed by an urgent referral to a specialist service, either a child and mental health service (CAMHS) or, when in existence, a specialist psychosis service," they explained.

If the child is considered to be a danger to themselves or others, ‘they will be referred for a same-day specialist assessment and may require hospitalisation'.

While every effort should be made for them to agree to such an admission, if they do not, a compulsory admission may be made under section 25 of the Mental Health Act 2001.

"Most patients will ideally comply with admission, however in 2011, 21 involuntary admissions to approved centres (12 child units and nine adults units) within Ireland were necessary," the doctors noted.

Treatment includes medication and psychotherapy.

"Some 20% of patients with schizophrenia will return to normal functioning within five years of the onset of the illness, but 60% will experience relapses throughout the course of their life. The remaining 20% will have persistent symptoms and find it difficult to live independently," the doctors explained.

They said that it is important that warning symptoms are recognised ‘as early as possible and that intervention and treatment is implemented without delay'.

"Suicide is a particular risk in people with schizophrenia and highest within the first year following their diagnosis."

They added that the transition from child and adolescent services to adult services must be well planned to ensure ongoing engagement.

The doctors made their comments in the Irish journal, Psychiatry Professional.