Oppositional defiant disorder (ODD) is challenging enough on its own, but it's made worse when it coexists with other behavioral and psychological problems. Unfortunately, about 90 percent of children with ODD meet the criteria for a diagnosis of at least one other condition, such as anxiety, attention deficit hyperactivity disorder (ADHD), conduct disorder or substance abuse problems [source: Nock]. ODD is also common in children with Tourette syndrome, Asperger syndrome and sensory processing disorders. In most cases, ODD appears first. One exception is ADHD, which more often shows up before ODD in patients with both conditions.
Among children with ADHD, about 40 percent also have ODD [source: Biederman]. The link between ADHD and ODD is not well understood, but there is a lot of research currently underway on the subject. This is partly owing to the fact that people with a childhood history of both ODD and ADHD have high rates of psychiatric and psychosocial conditions compared with people who have ADHD alone [source: Harpold].
Another condition that is closely linked with ODD is conduct disorder. Conduct disorder is considered a more serious version of ODD since it involves cruelty to people or animals, destruction of property and theft or other serious rule violations. By contrast, kids with ODD do not usually hurt people, steal or destroy property. It is important for parents of a child with ODD to be aware of the symptoms of conduct disorder, since nearly half of ODD patients will eventually develop this condition [source: Nock].
ODD is also closely associated with depression, anxiety and substance abuse problems [source: Biederman]. In fact, about half of ODD patients will go on to develop one of these conditions. Having one or more of these conditions is usually a bad sign. ODD that coexists with one or more other conditions is associated with worse outcomes in the long-term.
ODD, ADHD and conduct disorder are the three most common reasons for referral to mental health services among children. Of the three, ODD is considered the mildest condition. This may be because the symptoms of ODD are closest to what's considered "normal behavior" for children. That doesn't mean that ODD is easy to treat, as we will explore in the next section.