There are two things that could cause that in relation to CHA, and in my opinion it’s most likely a combination of both.

1. One can’t simply vent their anger, depression or anxiety at anyone and everyone, so CAH people are forced to learn to control that. That control wouldn’t stop when the hormones shift back in balance, and therefore that control helps them be more stable, balance and generally cheerful during those times when their hormones are not adversely affecting their emotions.

2. The same hormonal/chemical causes that produce anger and depression can also produce euphoria and a general feeling of well being.