With the legalization of marijuana, Courts have a unique challenge in family law cases involving parenting time and parental responsibilities. The use of alcohol, although legal, can impair a parent's ability to care for their children. At times, it is appropriate for the Court to limit a parent's use of alcohol. The use of marijuana, although legal, can likewise impair a parent's ability to care for their children. When faced with a request to place limitations on a parent's use or consumption of a legal substance in a child custody case, the Court must determine whether the parent's use of the substance has or is likely to place their child in harms' way. The Court determines this by looking at the evidence. The Court may look at whether or not the parent has consumed alcohol to the point of intoxication while caring for a child, whether the level of intoxication was such that the parent's ability to care for the child was impaired, and how often a parent becomes intoxicated. The Court would look at similar evidence with respect to marijuana use. In fact, in child custody cases, the Court must determine the same questions when considering a parent's use of any type of mood or mind altering substance, including marijuana. http://www.denverpost.com/ci_22445228/parenting-and-pot-divorce-lawyers-perspective-marijuana-legalization
What are some of the key differences between alcohol and marijuana? From a social perspective, drinking alcohol with moderation (and in excess) has deep roots in American history as a socially acceptable and common practice. The use of marijuana, however, has been marginally accepted for medicinal and illicit use. The reasons for consuming these two substances often differs as well. A person who smokes marijuana typically does so to achieve an altered state of mind whereas a person who drinks one glass of wine at dinner is more likely to be presumed to have done so for the taste. As such, Courts may still draw a clear line between moderate use of alcohol and any use of marijuana in child custody cases. The difference may simply lie in the purpose--a person who consumes any substance (legal or illicit) while caring for a child for the purpose of achieving a state of high or intoxication is going to be a concern for a Court. http://www.csmonitor.com/Commentary/Opinion/2013/0304/How-legal-marijuana-will-affect-troubled-families
In addition, far less information is known about the effects of marijuana as it relates to quantity compared to alcohol. For example, a court is not likely to be concerned about a parent who consumes one glass of wine at dinner because it is generally known that one glass of wine will not impair a persons ability to attend to the needs of a child. However, it is widely believed that a person who consumes one marijuana joint will be impaired significantly more so than a person who consumes one glass of wine. If marijuana use were as widespread as the consumption of wine, the line between problem versus safe use of marijuana would be easier drawn in child custody cases.
With the passage of time, Courts will undoubtedly become more comfortable drawing the line between problem use of marijuana just as they have become experienced in drawing the line between alcoholics and those who drink in moderation. Courts will also become more comfortabe when they are presented with testing mechanisms that will allow them to determine the level of the marijuana the person consumes on a regular basis and when standards of use (versus abuse) are established (if ever). The key question will be whether or not Courts ever view the consumption of marijuana to be an activity that has any value other than achieving a high as it will not likely ever be acceptable for a court to accept a parent's claim that he or she is entitled to be high when parenting their children.
The difficulty the Court faces is determining when an individual must be restricted from the use of any substance. Many types of evidence is relevant. Testimony from witnesses who have observed the the parent using any substance in the presence of children to the point of impairment would be relevant. Evidence that the parent has demonstrated an inability to understand the gravity of effect their consumption has on their senses (such as a DUI or a DWAI) is evidence that the parent may have an addiction that, without restriction, would place their children in harm's way. Evidence that the parent allows the child to inhale or otherwise consume marijuana by smoking in the child's presence (much like smoking cigarrettes in close proximity to the child) would raise concerns. Finally, habitual use of a substance is going to cause the Court concern as habitual use is more likely to be a problem when parenting a child because it becomes less likely that the user will be able to limit their use when necessary for the safety of the child.