What happens if someone fails a court ordered drug test during a child custody hearing?

While judges differ in their responses to positive drug test results, and much depends on the history of the case and prior orders entered, a common response would be mandatory testing for some time going forward and a warning that continued illegal drug use could constitute grounds for a loss of custody.  If a report is made to Child Protective Services, and the mother's drug use is found to constitute a basis for finding abuse or neglect of the other child, that child could be removed from the home as well.