Family courts in California and around the U.S. base child custody decisions on the best interest of the child. When a parent has concerns about the other parent's abuse of alcohol, illegal drugs or prescription drugs, a judge would consider how this behavior could impact the safety of the children. Someone wishing to address a parent's substance abuse could do so at the initial child custody hearing or request changes after a court has already issued an order for custody and visitation.
When a court is reviewing a custody agreement for the first time, a parent could express concerns about the other parent's substance abuse. A judge could order an investigation into the other parent's ability to care for children. The court will try to confirm the allegations and then evaluate whether the drinking or drug use could impede parental abilities or endanger the children. The findings of this investigation would influence the court's final decision.
If drug or alcohol abuse emerges as a problem after custody has been established, then the concerned parent could file a complaint with a family court. Complaints that present documented evidence, such as an arrest for drunk driving or a report from a child protective services agency, could prompt a judge to restrict one parent's access to the children. Supervision might be imposed during visits or shared custody might be changed to sole custody for the other parent.
A parent worried about the child's exposure to drug or alcohol abuse could work with an attorney to achieve sole physical custody. The attorney could gather evidence about the other parent's problem. Requests to modify an existing custody order could be prepared by the attorney. These efforts could help a parent present a strong and clear case to the judge.