Mood instability at home but not at school

My son was recently diagnosed with mood dysregulation.....our biggest problem is that he presents differently in school....he is very socially anxious and mimics normal to the best of his ability (really well) unless in the comfort of someone he knows very well. My question is, Is it always necessary for a psychiatrist to see the behaviors described. We keep running into "we don't see that here". It was after I detailed out everything he was saying appearing, eating, doing for 3 days between stay one and two that he was diagnosed. Now on his third stay we still hear we don't see that. But his in home therapist (who he has become familiar and more comfortable ) did note his elevated, hyperactive , distractable mood for the past two weeks at least before his most recent stay.

It is not unusual for the most severe mood dysregulated behavior to come out at home and not to be evident in the school or treatment settings. Some kids with bipolar, severe mood dysregulation, and even ADHD can hold it together in the more structured settings (in part because they don't want to lose control and be disciplined in front of their peers) but then "let loose" when they get home. This may be in part because the home setting is safer (as you say, he shows these behavior with people with whom he's more comfortable) or because school is such a structured activity.

Here are some general suggestions for parents who find that kids show greater mood insatbility at home after school. It may or may not apply to your son:

Increase structure at home- i.e., when child gets home, make sure s/he has some rewarding activity or an hour or so, then make the rest of the afternoon and evening predictable--- dinner from 6-7, homework from 7-8, TV from X to Y, bath from Y to Z, etc (there is no particular time allotment or order that is best- the issue is that it be predictable). If possible, reward him or her for sticking with this routine.

Keep a mood chart (record highs, lows, periods of irritability/anger/aggressiveness) on a daily basis, and also keep track of sleep/wake cycles.

As far as the school or doctor who says "we don't see that here": For the school, it only helps for them to know about the bipolar-like behavior if you want them to accommodate him/her somehow, i.e., there are things they could be doing that would increase his mood stability. For the psychiatrist, bring in your daily/nightly ood chart to give him/her a better sense of how much variability there is at home versus school, on weekends, and after nights of poor versus good sleep.