Substance Abuse and Child Custody

 Posted on April 16, 2026 in Child Custody

A child's best interest will always come into play when a judge makes decisions about child custody, known as parental responsibilities in Illinois. When a child's parent has a problem with substance abuse, the judge can deem the parent unfit to spend time with the child or to make decisions on the child's behalf. In the most serious cases, a judge could revoke parental responsibilities and parenting time altogether.

Parents with a substance abuse problem can exhibit unpredictable and erratic behavior. Your child should not have to endure such a dangerous environment and the law in 2026 gives parents options for keeping their children safe. Get help for your child by consulting a Kendall County child custody attorney as soon as you have concerns about your ex’s drug or alcohol use. 

What Is Substance Abuse and How Does Illinois Define It?

Drug addiction, or substance use disorder, is a condition in which a person is out of control with their use of drugs, either legal or illegal. Alcohol, prescription drugs, nicotine, illegal narcotics, and even caffeine are all considered substances.

Illinois courts don’t particularly care whether the substance being used is legal or illegal when a child’s safety is at stake. A parent who is addicted to prescription painkillers or who drinks heavily can also have a substance use problem that affects their fitness as a parent.

According to the National Survey on Drug Use and Health, almost 50 million Americans aged 12 and older met the criteria for a substance use disorder in 2022. That’s almost one in five Americans, making this a common issue that Illinois courts are familiar with and know how to handle. 

Under 750 ILCS 5/602.7, Illinois courts must evaluate the best interests of the child when making parenting decisions. Substance abuse by either parent is one of the factors explicitly considered under this standard. If a parent's drug or alcohol use creates any risk to the child's physical safety, mental health, or emotional development, the court can and will act.

What Effect Does Substance Abuse Have on Child Custody in Illinois?

Parental responsibilities and parenting time can both be restricted by Illinois courts. If a judge considers a child's physical, mental, or moral well-being in danger because of a parent's substance abuse, they can take away that parent's right to be around the child.

The court can order the addicted parent to seek help for the drug or alcohol abuse and give parenting time to another responsible adult while the parent gets treatment. Anyone enabling substance abuse can also be court-mandated to not be around the child.

The types of restrictions a court might decide are best for the child include:

• Supervised visitation, where a neutral third party must be present during all parenting time

• Drug testing before or after visits

• Prohibition on consuming alcohol or drugs within a set number of hours before picking up the child

• Completely stopping parenting time until the parent completes a rehabilitation program

• Transfer of decision-making authority to the sober parent for medical, educational, and other major life choices

Courts do not have to take away parenting time permanently. The goal is usually to protect the child while also giving the struggling parent a realistic path to recovery and reunion with their child.

How Does the Court Know What the Best Interests of the Child Are?

Some parents have a hard time understanding how a judge, who probably has never met the child before, can possibly understand what the child’s best interests are. It’s a fair question, and one that Illinois is careful to address. 

A judge will need to look at many factors before making important decisions on a parent's rights to their child. These include: 

• The parents’ current behavior and history of behavior 

• What the child wants

• What the child needs

• What the parents want

• How easily a child will adapt to a change in living arrangements

• The mental and physical health of both parents and child

• The willingness of each parent to support the other parent's relationship with the child

• Any history of domestic violence or abuse

• The stability of each parent's home environment

When substance abuse is part of the picture, judges pay close attention to how long the problem has been going on, whether the parent has sought treatment, and whether the parent acknowledges the issue at all. A parent who is actively in recovery and following a treatment plan will be treated differently from one who denies having a problem.

If a judge can’t get enough information on their own, the court may appoint a guardian ad litem to investigate and report on what custody arrangement would truly serve the child best. A guardian ad litem is a person appointed to represent the child's interests during the legal process. 

What if Substance Abuse Develops After a Child Custody Agreement?

An Illinois custody order can be modified at any time. All it takes is filing a motion with the court. The parent accused of abusing drugs can be required to take a drug test. Even if the parent refuses to take the test, the judge can change a custody order. To request a modification, you will generally need to show:

• That a substantial change in circumstances has occurred since the last order

• That the change directly affects the child's welfare

• That modifying the order is in the child's best interest

Evidence of substance abuse can include drug test results, police records, witness statements from teachers or family members, photos or videos, or social media posts. The more documentation you have, the stronger your case.

Call a Batavia, IL Child Custody Modification Lawyer Today

Every good parent should be concerned with the dangers another parent may pose to their child through substance abuse. The Law Office of Matthew M. Williams, P.C. can provide legal guidance and assistance to help protect your child and represent you in court. Do not let your child be placed in a dangerous situation. For a skilled Kendall County, IL child custody lawyer, call The Law Office of Matthew M. Williams, P.C. at 630-409-8184 and let us protect your rights.