Multisystemic therapy (MST) is a form of therapy that relies on interaction with the family unit and the larger community to curb the antisocial behaviors that sometimes occur in teenagers. Unlike some other forms of therapy, it\u2019s specifically designed to deal with teens who have highly entrenched behavioral problems that typically result in problems with the legal system. According to the results of an extensive study review published in 2013 in the journal Psychiatric Times, participation in a multisystemic therapy program can lead to significant reductions in adolescent use of alcohol, marijuana or other single substances, as well as combinations of these substances. Teen Substance Abuse Basics The U.S. government tracks teen and preteen substance use trends with the help of three separate nationwide surveys. The most recent available figures compiled from these surveys indicate that roughly half of all American high school seniors have a current or past history of using an illegal or illicit drug. In addition, almost 66 percent of all seniors report a current or past history of alcohol use that resulted in drunkenness. While some teenagers use only one drug or only drink alcohol, many other teenagers participate in what\u2019s called polydrug use, a practice that involves the simultaneous use of two or more substances. Fewer than one out of every 10 teen substance users undergoes treatment for his or her drug or alcohol use, the authors of the review in Psychiatric Times report. Even fewer teenagers receive treatment with a scientifically verified history of effectiveness. Multisystemic Therapy Basics Multisystemic therapy gets its name because it involves treatment that addresses each of the \u201csystems\u201d that factor into a teenager\u2019s health and well-being, including his or her family and home environment, social circle, neighborhood environment, school environment and interactions with teachers. During therapy, MST practitioners typically meet their patients in the home, where they focus on such things as assessing and improving parenting abilities, and assessing and improving the quality of the relationships a teen has outside the home, including the relationships with his or her peers and larger community. As a rule, MST practitioners are available to their patients at all times, only work with a small number of patients at any given time, and place special emphasis on positive critiques during the treatment process. A typical course of multisystemic therapy lasts for about one-third of a year. During this time, therapists typically meet with their patients and patients\u2019 families several times a week. MST for Teen Substance Abuse Multisystemic therapy comes in several different forms, including forms specifically designed to address the effects of substance abuse. One specific example of a substance abuse-focused MST approach is known as multidimensional family therapy or MDFT. This approach puts emphasis on four individual areas of treatment: overall function of the family unit; the teen patient as an individual, as a part of the family and as part of his or her peer groups; the parents as individuals and as part of the larger family unit; and the ways in which family members communicate with each other and with important community institutions. Effectiveness Generally speaking, substance abuse specialists and mental health professionals have a strong preference for treatment approaches that can be scientifically tested and assessed for effectiveness. The accepted term for treatment that passes scientific scrutiny is evidence-based treatment. Multidimensional family therapy meets the relevant criteria as an effective, evidence-based treatment for teen substance abuse, the authors of the review in Psychiatric Times conclude. Various studies have demonstrated its usefulness in treating teens with isolated alcohol-related problems and isolated marijuana-related problems, as well as teens involved in polydrug use. In addition to reducing substance use in the average affected teenagers, MDFT also reduces substance use in high-risk individuals and in individuals who have already had run-ins with the legal system. In addition, MDFT appears to provide significant benefits for heavy substance users and teens who have other physical or mental problems apart from their substance abuse-related issues. Considerations In addition to curbing substance use, multisystemic therapy programs targeted at teen substance abusers can also produce substantial reductions in other forms of illegal or criminal behavior. In particular, MST therapy can potentially produce a steep reduction in participation in criminal acts involving aggressive or violent behavior. However, teens who go through a substance-focused MST program typically experience no real reduction in their involvement in crimes against property.