Disorders of Attention and Activity 59Differential diagnosis
1 Normality. Parents may complain of minor degrees of restlessness and
inattention that are well within the normal range. Simple exuberance
can be wearing for parents and teachers; this requires sympathy rather
than a diagnostic label!
2 Situational hyperactivity. Some children and adolescents seem to be hy-
peractive and inattentive in just one setting, such as at school but not at
home, or vice versa. These individuals cannot be diagnosed with ADHD
or hyperkinesis under current rules since cross-situational pervasiveness
is required. In some instances, situational symptoms may be a milder
variant of pervasive symptoms, simply being more recognisable in one
setting rather than the other. In other instances, though, situational
symptoms reflect situational stresses. For example, symptoms limited to
school can be the result of specific learning difficulties, while symptoms
limited to the home can reflect home-based difficulties with relation-
ships or behaviour.
3 Behavioural disorders. While it is true that ADHD and disruptive be-
havioural disorders often occur together, it is also possible for ‘pure’
disruptive behavioural disorders to mimic ADHD. Impulsiveness is a
feature of both disorders (see Box 6.3 on p. 71). In addition, children
and adolescents with behavioural problems at school may not want to
settle to school-work and may wander about the classroom creating
trouble. Similarly, children and adolescents with behavioural problems
at home may not settle to their chores or their homework. The key ques-
tion is whether restlessness and inattentiveness persist during chosen
activities, such as drawing, reading comics, building models, or playing
with friends. If the answer is ‘no’, this is unlikely to be ADHD; if ‘yes’,
this may be a mixture of ADHD and a behavioural disorder (depending
on pervasiveness, age of onset, etc.).
4 Emotional disorders. Severe anxiety, depression or mania can all result in
restlessness and inattentiveness (in which case, a diagnosis of ADHD is
ruled out). When assessing someone with a mixture of ADHD symptoms
and emotional symptoms, it is essential to take a careful history to
establish which began first. If the emotional symptoms came first, the
right diagnosis is probably just an emotional disorder. However, if the
ADHD symptoms came first, this may be an acute emotional disorder on
top of a chronic ADHD problem.
5 Tics, chorea, and other dyskinesias. These may be mistaken for fidgetiness.
Observe the movements carefully. Children with tic disorders may also
have ADHD and the ADHD may have been evident long before the
first tic.
6 Autistic spectrum disorders. ASDs are suggested if the restlessness and
inattentiveness are accompanied by autistic types of social impairment,
communication deviance, rigid and repetitive behaviours, or lack of
spontaneous pretend play.