Wouldn't call BPDO a "disability" per se, and the question you're asking is complicated. The presence of BPDO in children is fairly low, and arguably overdiagnosed. On the coattails of that idea, the other "disabilities" that children are diagnosed with who are oft struggling with comorbid (co-occurring) BPDO (ADHD, learning disorders and such) are even more overdiagnosed.
Where I'm going with this unfortunately, is a lot of behaviors that get children both of these diagnoses also sometimes mirror the behaviors of children who have abuse issues, families with addiction problems and etc. That's likely a contributing factor in the overdiagnosis of these issues. The answers to your question are only relevant in terms of treatment of course, and the treatments that have become "community standard" are almost exclusively medicines. While these are helpful in situations where there are good diagnoses, if the client is not truly BPDO'd, ADHD etc, the other causal factors for suffering may be overlooked.
They are getting very liberal with the diagnosis of pediatric bipolar disorder. In theory, it's a very rare condition, but that's only when it looks like manic depression; now, they medicate moody, depressive, perhaps volatile children and adolescents, not so much with mood stabilizers (they're not designed to make moody children behave, and they're cheaper than dirt) as with expensive new schizophrenia medicines, the atypical antipsychotics. They need to watch for signs of bipolar disorder in the teen years- major depressions are the key sign- and be wary if an SSRI or ADD med causes a hypomanic reaction. That could presage the full-blown mania of the adult bipolar. But as for adolescents being treated for a disorder they probably don't really have with knockout drugs for schizophrenia, I think that's a bit much.