Here is more information about what a 5150 (involuntary psychiatric hold) is.
There is advance coordination with the authorities for the second hold on the 27th:
Britney is immediately placed in a conservatorship during the second hold.
The conservatorship is temporary at first and gets extended multiple times:
While Britney is under the temporary conservatorship, she appears on How I Met Your Mother and her conservators retain an entertainment lawyer for “new potential matters.”
The conservatorship is made permanent in October 2008.
Once the conservatorship is made permanent, stories come out every few years, putting a positive spin on the arrangement and/or justifying its need:
The Girl, Interrupted scene we mentioned.