5. Differential diagnosis and other co-existing conditions
Overall perhaps as many as 65-70% of children with ADHD will have one or more co-morbid psychiatric or other conditions (Beiderman et al. 1991). Co-morbidity is therefore the rule rather than the exception. The assessment process should therefore take account of other conditions, which may better account for the behaviours causing concern. These might include:
- disinhibited attachment disorder;
- over-activity associated with autistic spectrum disorders - including Asperger's syndrome;
- conduct disorder (CD);
- anxious in-attentiveness secondary to stress and trauma;
- agitated depression;
- past closed head injury;
- attention deficit without over-activity;
- Gilles de la Tourette syndrome;
- chromosomal disorders e.g. Fragile X syndrome;
- lack of consistent parenting;
- specific learning difficulties;
- physical or sexual abuse or neglect.
The assessment process should also consider other conditions, which frequently exist alongside ADHD such as:
- oppositional defiant disorders (ODD) (35%);
- conduct disorders (26%);
- specific learning difficulties;
- depression (8%) and/or anxiety disorder (26%);
- speech and language difficulties;
- developmental co-ordination disorder (DCD) (50%).
