One of the difficulties in diagnosing ADHD is that it is often accompanied by other problems (Co-Morbidities). For example many children with ADHD also have a specific learning disability (LD), which means they have trouble mastering language or certain academic skills, typically reading and maths.
ADHD is not in itself a specific learning disability. But because it can interfere with concentration and attention, ADHD can make it doubly hard for a child with LD to do well in school.
Disorders that can accompany ADHD:
Affects approximately 30 to 50 percent of children with ADHD. In preschool years, these disabilities include difficulty in understanding certain sounds or words and/or difficulty in expressing oneself in words. In school age children, reading or spelling disabilities, writing and maths disorders may appear. Dyslexia, a neurologically based disorder that inhibits orderly achievement and processing of linguistic information is also a widespread co-morbidity.
Oppositional Defiant Disorder (ODD)
As many as 40 to 60% of all children with ADHD – mostly boys – have ODD. These children are often defiant, stubborn, non-compliant, have outbursts of temper, or become belligerent. They argue with adults and refuse to obey.
Conduct Disorder (CD)
About 20 – 40 percent of ADHD children may eventually develop CD, a more serious pattern of antisocial behaviour. These children frequently lie or steal, fight with or bully others, and are at a real risk of getting into trouble at school or with the police. They violate the basic rights of other people, are aggressive toward people and/or animals, destroy property, break into people’s homes, commit thefts, carry or use weapons or engage in vandalism. These children or teens are at greater risk for substance use experimentation, and later dependence and abuse. They need immediate help.
Anxiety and Depression
Children with ADHD often have co-occurring anxiety or depression. If the anxiety or depression is recognised and treated, the child will be better able to handle the problems that accompany ADHD. Conversely, effective treatment of ADHD can have a positive impact on anxiety as the child is better able to master academic tasks.
There are no accurate statistics on how many children with ADHD also have bipolar disorder. Differentiating between ADHD and bipolar disorder in childhood can be difficult. In its classic form, bipolar disorder is characterised by mood cycling between periods of intense highs and lows. But in children, bipolar disorder often seems to be a rather chronic mood disregulation with a mixture of elation, depression and irritability.
Furthermore, there are some symptoms that can be present both in ADHD and bipolar disorder, such as a high level of energy and reduced need for sleep. Of the symptoms differentiating these two disorders, elated mood and grandiosity of the bipolar child are distinguishing characteristics.
A very small proportion of people with ADHD have a neurological disorder called Tourette syndrome. Symptoms include various nervous tics and repetitive mannerisms, such as eye blinks, facial twitches, or grimacing. Others are frequent throat clearing, snorting, sniffing or barking out words. These behaviours can be controlled with medication.
Autism Spectrum Disorders
This term refers to Autism, Asperger’s syndrome, Pervasive developmental disorders, and high-functioning Autism. ADHD and especially Asperger’s syndrome are closely related disorders which share many similar characteristics. In both, there is trouble with self-talk, self-awareness, the reading of social cues, and the demonstration of empathy. Both groups generalise rules poorly, and do better with predictability and routine.