Recognising when a child is suffering from mental illness is difficult, but psychiatrists believe that teachers could be in the front line of detection and support.

The most common childhood mental illness is anxiety disorder, which affects about 12 per cent of all children. This can range from separation anxiety in young children to phobias, panic attacks and sleep problems in older children and adolescents.

These forms of anxiety, which can be mild or severe enough to be disabling, can be triggered by external events, such as divorce in the family, or they may be unrelated to anything obvious. Depression, which affects 5 per cent of teenagers, is a common denominator of several mental illnesses that children may experience, and it can also occur on its own.

But at a recent conference in Bristol organised by the Wellcome Trust, Dr Rebecca Park, of Cambridge University, documented how easily depression was overlooked. Classic symptoms such as social withdrawal, irritability and poor concentration are so often put down to general adolescent malaise.

In a Cambridge study of 365 12 to 16-year-old girls, 28 showed signs of clinical depression that had gone undetected for some time; 13 others had been recently depressed, also without receiving help.

Around 40 per cent of adolescents with depression suffer from anxiety, behaviour disorder and obsessivecompulsive disorder. Depression is also often a symptom of schizophrenia, another notoriously difficult condition to recognise, which affects one in 100 adults but which is unlikely to surface before the age of 15.

The way symptoms of depression present themselves is dictated by the age of the sufferer. While younger children aged 11 and 12 are less verbal and are often overwhelmed by feelings of hopelessness, depression in 13 and 14-year-olds is more obvious and accompanied by cognitive difficulties, impaired performance and indecisiveness.

When they reach 15 and 16, depression can be characterised by agitation and suicidal thoughts.

“There’s a lot of unrecognised child depression in the community,” said Dr Park. While social factors are partially responsible, particularly situations like family breakdown, abuse and bereavement, research shows that these triggers alone don’t cause a child to be depressed. Children whose parents have mental-health problems or those with reactive temperaments, for instance, are more at risk.

Despite the confusing picture, said Dr Michael Owen, of Fulbourn Hospital, near Cambridge, teachers need to be alert to the signs of mental illness as part of their pastoral role. “While they can’t refer directly to psychiatric services, they can alert the appropriate services within education.”

WHO TO TURN TO

The Mental Health Foundation provides information to the general public on all aspects of mental health as well as funding research and promoting the development of appropriate services. Tel: 0171 535 7400.

Young Minds works to increase public awareness of the mental health needs of children, young people and their families and promotes mental health services for them. Tel: 0171 336 8445.