28 Chapter 2
as a result of biological maturation. The partition of developmental disor-
ders between different disciplines has largely been determined by history
and convenience. Conventionally, some developmental disorders, most
notably the autistic disorders, are considered primary psychiatric disorders.
Enuresis is sometimes considered a psychiatric problem, though there is
little justification for this practice (see Chapter 18). Most developmental
disorders are not generally considered psychiatric disorders in themselves,
though they are often risk factors for psychiatric disorders (which is why
they are covered in this book in Part 3 on risk factors)
The dividing line between the three main groupings is not always
clear-cut. ADHD, for example, is usually grouped in the externalising
disorders, though it could equally be considered a developmental disorder,
particularly affecting the development of attention and activity control.
Similarly, depression is grouped with the emotional disorders even though
the dominant symptom in children and adolescents is sometimes irritabil-
ity, which is commonly a symptom of externalising disorders.
Opinions differ on the extent to which it is helpful to subdivide the main
groupings. Until about 20 years ago, for example, few clinicians saw much
merit in subdividing the emotional disorders into different subgroups, and
ICD-9 offered little opportunity to do so. Then the pendulum swung from
lumping to splitting, with both ICD-10 and DSM-IV offering a multitude
of emotional disorder. The pendulum may swing back again since splitting
has probably gone too far, with too many children and adolescents meeting
the criteria for multiple closely related disorders.
The swing of the pendulum has also been evident in the extent to
which children are regarded as being ‘little adults’ as far as diagnosis is
concerned. There are two polar views of childhood: one view holds that
children are radically different from adults, rather like tadpoles and frogs;
the other view holds that children and adults are fundamentally similar.
As far as psychiatric classification goes, the ‘tadpole and frog’ view used
to dominate, but seems to be waning. For emotional disorders, adult-
type diagnoses such as dysthymia or generalised anxiety disorder are used
where possible. At the same time, there is an increasing recognition that
developmental disorders and disruptive behavioural disorders often persist
into adult life. Thus a picture of separate child and adult disorders seems to
be in decline. Instead, most disorders are seen as conditions that can occur
across the lifespan, with the recognition that the characteristic symptoms
may vary at different ages, and so too should the diagnostic criteria. For
example, the criteria for ADHD recognise that affected adults experience
less fidgeting and rushing around than when they were children, but ex-
perience more of an inner sense of restlessness instead. Likewise, modified
criteria for post-traumatic stress disorder (PTSD) in very young children
recognise that a continuing preoccupation with the trauma may be shown
in their pattern of play rather than in what they say.
Finally, it is important to remember that the psychiatric disorders affect-
ing children and adolescents are not limited to the three main groupings.
There are inevitably disorders that do not fit into the neat tripartite