Child and adolescent mental health encompasses a wide range of disorders including learning disability, autism and ADHD as well as so-called 'adult' conditions that may also affect children. These disorders can have important effects on a child's development, and so their early detection is quite important. However, it is worth bearing in mind that behaviour such as tantrums and bed-wetting are normal in a two year-old and only become abnormal at an age where most children have stopped them. Children with mental health problems can present differently from adults, often having non-specific problems with their behaviour, and they may well present to a doctor after an adult notices that something is amiss. This entry covers those conditions that only occur during childhood, though some may persist for the rest of a person's life.

Learning Disability

Far from being a specific diagnosis, learning disability encompasses a range of problems of varying severity. It is defined as abnormal development of the brain leading to an IQ below 70 along with difficulties with adaptive functions such as academic and social skills and independent self care. There are many causes of LD, including Down's Syndrome, autism, complications during pregnancy, trauma at birth and childhood infections; however, in 40% of cases there is no clear cause. It is possible to prevent some LDs through improved care during birth and early childhood and through the controversial process of antenatal screening for conditions such as Down's Syndrome with a view to abortion.

Though around 1% of individuals have some form of LD, 85% are only mildly affected and have an IQ greater than 50. These individuals are able to achieve the basic standards of learning given the right support, and are often able to live and work independently. A further 10% have a moderate LD and are able to live and perform simple work with an appropriate degree of supervision. A small number of individuals with LD are severely affected, have great difficulty learning to move and speak, and require life-long care. Remember that most children with learning disability are able to achieve a certain degree of normal function, and are greatly helped by supportive learning and family environments. In the UK, assessment of learning needs and support at school are arranged with the help of a SENCO¹, and there are a number of support groups and programmes that GPs may refer families to.

Developmental Disorders

The developmental disorders are a mixed bunch of conditions that share a common thread of leading to an impairment of expected skills. The specific developmental disorders are those that affect a specific function such as spelling, reading or mathematical ability, while leaving other areas unaffected. Children with specific disorders do not have the same difficulties with social and academic function as those with learning disability, but may still struggle due to problems with a specific area. The best example is dyslexia, which causes an impairment in an individual's ability to read; other specific developmental disorders can affect areas such as spelling and mathematics.

The pervasive developmental disorders are quite different in that they affect all areas of an individual's functioning, and typically involve impairments of socialisation, communication and behaviour. These conditions are often associated with learning disability, but it is the individual's behaviour that makes them characteristic. The pervasive developmental disorders include:

• Autism – the hallmarks of autism are poor social skills, poor language and communication skills, and restricted behaviour and interests. These symptoms develop before the age of three, and the condition may become apparent through a regression of language skills. Limitations of social skills include poor eye contact, limited body language and a failure to form normal interpersonal relationships. Communication is hampered by a narrow lexicon, literal usage of words and difficulty holding conversations with others. Interests are often very restricted and focus on a single subject; behaviour is repetitive and includes both pointless movements and unusual preoccupation with parts of objects.

  Autism is around four times more common in boys, though it affects girls more severely. While 75% of children with autism have a significant learning difficulty, some have a normal level of intelligence. Only a quarter are able to achieve some degree of independence later in life, and so a supportive and understanding family is vital.

• Asperger's Syndrome  – though it has a place on the 'autistic spectrum', Asperger's is a distinct syndrome. Though symptoms such as narrow interests, social difficulties and odd behaviour still feature, the syndrome does not affect the individual's language skills or intelligence. The condition persists into adulthood, and individuals are often clumsy and have obsessive or socially-isolating patterns of behaviour.

• Rett's Syndrome – seen exclusively in girls, Rett's is a rare disorder that begins around six months into the child's life. An abnormal gene on the X chromosome leads to faulty brain development, producing a loss of language skills and fine motor movement along with a slowing of head growth. The child develops odd, repetitive hand movements and hyperventilation, and eventually loses the ability to talk, walk and control of their bowels.

• Heller's Syndrome – also known as childhood disintegrative disorder, Heller's is a rare syndrome involving a regression of language, social and motor skills and bowel and bladder control. It occurs around the age of two years in children with previously normal development, and is thus similar to severe autism.

Developmental disorders are not curable and so treatment is aimed at dealing with symptoms and supporting the individual. The treatment of autism consists largely of special provision for any behavioural difficulties and learning disability. While a number of medical treatments have been suggested, there is little evidence except for the possibility of using anti-psychotics in children with severe behavioural problems.

Asperger's Syndrome is also treated largely with social skills training, cognitive therapy and so forth, though treatment of co-existing depression and anxiety is also helpful. Treatment of Rett's Syndrome deals with issues of feeding, constipation, communication and immobility and includes heavy parental involvement and training. Heller's Syndrome has no specific treatment other than re-teaching skills that have been lost and making provisions for learning disability.

Acquired Disorders

The acquired disorders are different from the above that the a normal child may develop one, but would be a normal child again were the illness to be removed. They include Attention Deficit Hyperactivity Disorder, (commonly known as ADHD), conduct disorder and various emotional disorders, all of which generally have their onset in childhood or adolescence.

ADHD or hyperkinetic disorder as it is known outside of the USA, usually begins around the age of seven years, affects boys more than girls, and is characterised by a triad of impaired attention, hyperactivity and impulsivity. The impaired attention manifests as difficulty concentrating on a particular task, makes the child easily distracted and causes them to avoid tasks that require a high level of concentration.

The hyperactivity leads to restless, disruptive behaviour and problems taking part in calm, quiet activities. Finally, the impulsivity leads to disinhibited, reckless and unthinking behaviour that often appears antisocial. Children with ADHD often have difficulties getting on with their peers, and isolation may then lead to further antisocial tendencies.

Around 5% of children in the USA are diagnosed with ADHD, compared to around 1% in the UK, where the stricter diagnostic criteria for hyperkinetic disorder are used. The disorder tends not to be diagnosed in preschool children, as there is great variation in normal behaviour at this age. The cause of the disease is unknown, though central nervous stimulants such as methylphenidate (aka Ritalin) are thought to work by increasing the activity of areas of the brain associated with concentration. Family therapy, in which the parents are educated as to how best to manage their child's condition, is also used. The prognosis is usually good, with 85% of individuals lacking symptoms by adulthood.

Conduct disorder is a term used to describe excessively antisocial behaviour in children that recurs persistently and is beyond the usual bad behaviour expected for a child's age. Children with conduct disorder will repeatedly attack others, lie, steal, set fires and commit major violations of the rules that apply to their age group. The behaviour must persist for at least six months for a diagnosis to be made. Oppositional defiant disorder describes cases of conduct disorder that do not involve the most major violations of other people's rights, with the child instead having a persistent and severe difficulty following orders. Socialised conduct disorder, on the other hand, is used to describe conduct disorder that occurs when the child is socially capable but has fallen in with gang members or other dangerous youths. Overall, conduct disorder affects around 10% of adolescents, being more common in boys, and either improves by adulthood or develops into an antisocial personality disorder. Conduct disorder is treated using various forms of talking therapy and parent training.

A number of emotional disorders are worth mentioning here briefly:

• Separation anxiety disorder of childhood is a fear of separation from parents that persists beyond the usual age range of six months to two years, and which interferes with social functioning. In order to make a diagnosis, the anxiety caused must be specific to separation and must be abnormal for the child's age.

• Phobic anxiety disorder of childhood involves an abnormal level of phobia towards something of which children of the child's age are normally fearful. The term does not include non-specific disorders such as agoraphobia.

• Social anxiety disorder of childhood is an abnormal fear of strangers and anxiety when exposed to novel situations. Anxiety towards strange faces is normal between eight and twelve months of age, and this diagnosis is used if the anxiety is excessive or persists beyond this age.

• Sibling rivalry disorder describes an excessive level of jealousy of a younger sibling following their birth. Some degree of upset is inevitable, and so this diagnosis only applies to severe, persistent cases.

Other Childhood Disorders

Pica refers to the eating of non-food substances, ranging from soil and grass to tack and paint chippings. It occurs in very young children and those with pervasive developmental disorders, but may also occur on its own, in which case it is labelled pica of infancy and childhood. Pica is best treated by preventing the child from eating dangerous substances, and training them to eat properly through positive reinforcement.

Nonorganic enuresis refers to involuntary passing of urine not due to some medical cause in children who are toilet trained – generally over the age of five. Some children may suffer from nocturnal enuresis, aka bed-wetting, despite having had a period of being 'dry at night'. Around 10% of five year-olds, 5% of ten year-olds and 1% of adolescents are affected, and causes include life stresses, poor toilet training and various developmental disorders. There may be a genetic element, as around three quarters of children with nonorganic enuresis have a relative with the condition. Treatment involves parent training and behavioural therapy for the child, involving alarms that wake the child if urine is passed, and star charts with rewards for staying dry.

Nonorganic encopresis refers to the repeated passing of faeces² in inappropriate places, either involuntarily or with deliberate intent. It can occur as a continuation of infantile incontinence, as a regression following normal bowel control, or as a form of abnormal behaviour despite adequate control. It may occur alone, in which case family difficulties need to be considered, or as part of a wider problem such as conduct disorder or autism. Treatment involves ruling out an underlying cause and then providing toilet training with star charts and medication for constipation as need be.

Elective mutism occurs when a socially-anxious child refuses to speak in certain situations, but has an otherwise normal level of language development. It usually occurs in children starting at primary school, and is associated with other unusual personality features such as anxiety and difficult behaviour. This social reluctance often improves with age, and is helped by gentle encouragement.

Tic disorders are those characterised by sudden, involuntary movements or vocalisations. Tics are divided according to whether they are simple motor (blinking, grimacing), complex motor (jumping, hitting), simple vocal (hissing, barking) or complex vocal (repeating words, uttering obscenities). Transient tic disorder describes a syndrome lasting less than a year, usually involving simple motor tics. Chronic motor and chronic vocal tic disorder are diagnoses used when the tics persist for more than a year but are of one or the other type, whereas Gilles de la Tourette's syndrome involves multiple motor and vocal tics that persist in the long term. In the case of Tourette's, the onset is usually around the age of seven, and the treatment is most often with carefully monitored anti-psychotic medication.

And Finally

Bad habits such as nose picking, thumb sucking and nail biting are also on the ICD-10³ list of childhood disorders, and sufferers may wish to refer to the entry on Bad Habits and How to Stop Them.