It is a scientific fact that bipolar disorder happens in childhood, at least in adolescence down to age 12.
The only question is how it presents before age 12. The viewpoint that it NEVER happens is a belief-system, not a scientific hypothesis. If it is the latter, it is disproven, because adult criteria for mania can be shown in children below age 12.
Some will claim that those criteria, even with classic symptoms like grandiosity or euphoria, cannot be known to happen in children, since children can tend to be “silly” or grandiose “normally”.
It is hard to prove something when all evidence is rejected as proof. But at least one can ask another claim: If symptoms that are “manic-like” happen in a child who has a parent or other family members with adult bipolar disorder, it is scientifically highly probable that the child also has bipolar disorder. This is because bipolar disorder has about 80% heritability, which is quite high, and similar to schizophrenia and height.
It is completely illogical, for instance, to claim that a child had “major depressive disorder” (MDD) or ADHD when there are immediate family members with bipolar disorder. In the 1970s, the whole distinction between bipolar and unipolar depression had to do with genetics and course: MDD was defined as depression that happens in people without family histories of bipolar disorder. If depression happened in persons with family histories of bipolar disorder, then it was bipolar disorder. In fact, the old manic-depressive illness concept ignored all this: recurrent depression was manic-depressive, even without any manic episodes. If there is a family history of manic episodes, then this strengthens even further the view that a patient’s depression is biologically similar to bipolar disorder. Similarly, the genetic research indicates that most people with bipolar disorder do not have ADHD in their families, and vice versa. Thus, it is scientifically highly uncommon to have ADHD with a family history of bipolar disorder.
In short, in children, family history is highly diagnostic: It tells you what the symptoms really are - underneath their complex childhood manifestations; it tells you, ahead of time, what will become clear in adolescence and young adulthood. A family history of bipolar disorder means psychiatric manifestations of depression and anxiety and impaired attention are highly likely to be biologically related to childhood bipolar disorder. If we do not want to give the diagnostic label of bipolar disorder, that’s fine, as long as we draw the practical conclusions that those symptoms will respond as they do in people with bipolar disorder, meaning, as described further below, that antidepressants and amphetamines are likely to be either ineffective or harmful.
There is a cultural zeitgeist among child psychiatrists against the diagnosis of childhood bipolar disorder, and instead symptoms are given diagnostic labels, which is scientifically meaningless. Oppositional defiant disorder (ODD) and intermittent explosive disorder only mean that a child has irritability and aggressive behavior; ADHD only means that a child can’t concentrate; MDD means the child has depressive episodes. None of these definitions are diagnostically meaningful. Let me explain one by one:
Depression in childhood, in the absence of manic episodes, is typically diagnosed as MDD. But the average onset of mania is age 19. It is common for individuals with bipolar disorder to have depression as their first mood episode, followed by mania later. Thus, in prospective studies of children aged around 10, with about 10 year follow up into young adulthood by around age 20, researchers find that 25-50% of those children develop manic or hypomanic episodes. What this means is that about 25-50% of all children with “MDD” actually have bipolar disorder. A good hint about who has bipolar disorder, and who has unipolar depression, is, again, family history of bipolar disorder.
About 90% of all children who meet mania criteria also meet ADHD criteria, because distractibility is one of the core criteria for mania. To diagnose ADHD whenever there is attention impairment is like diagnosing “fever syndrome” whenever there is fever during pneumonia. It is consequence, not cause, in those cases. Rather, to diagnose ADHD, one should rule out childhood bipolar disorder first.
These aggressive and irritable symptoms can happen for a host of reasons, with mania being one cause. By themselves, these diagnoses are merely restatements of the symptoms, like fever syndrome, rather than scientifically and biologically valid disease entities.
A recent prospective 4 year outcome study followed children who are about age 10 have manic-like symptoms (meaning some manic symptoms but not enough in duration to meet full adult criteria of 4 days to one week of mania or hypomania or longer). When followed for about 5 years to mid-adolescence, about 1/3 of these children develop full hypomanic or manic episodes meeting adult criteria. This progression to bipolar disorder is more (about 1/2 ) in the presence of a family history of bipolar disorder, and less (about ¼) in the absence of a family history of bipolar disorder. Thus, with all the conflict and passion about whether such brief manic symptoms represent bipolar disorder, we can now say with solid data that the answer is: Sometimes. Again, the best predictor is: family history of bipolar disorder.
It is also relevant to point out that many clinicians treat ADHD with amphetamines, and then never stop the medications. They act as if the ADHD will never go away and will persist into adulthood in everyone. In fact, the literature from the 1980s and 1990s showed that ADHD in children was not diagnosable in 90% by age 20. Even more recent studies by persons who are highly supportive of the diagnosis of adult ADHD show that 2/3 of children no longer meet criteria for ADHD by age 18. Either way, in the majority of persons, ADHD goes away during childhood. Since patients often are diagnosed by age 8-9, it makes sense to revisit the use of these medications at the very least by early adolescence. Given the concerns about neurobiological harm from amphetamines, especially in the developing brain (see our review), it is even more important to avoid an attitude of denial about long-term risks with amphetamines.
The standard of practice in child psychiatry today is to diagnose one of the above conditions, which are merely restatement of symptoms, and then to treat those symptoms with drugs for those symptoms: antidepressants for depression, amphetamines for concentration, and antipsychotics for aggression. None of this is scientifically valid. Scientific medicine consists of the process of finding the biological diseases that cause symptoms. For instance, bipolar disorder could cause all the above symptoms. I am not saying it always does, I am just saying it could. Again, how do we know when it is more likely that bipolar disorder might be the underlying disease in children, where symptoms are so complex? Family history is the best resource.
But, there is a strong cultural zeitgeist against diagnosing childhood bipolar disorder. As is usually the case when it comes to science, such cultural fads are generally false.