January 13, 2010 — Individual-only interventions have larger effect sizes than those that are family based in reducing adolescent alcohol abuse, according to results from a new meta-analysis.

In addition, although effect sizes decreased as length of follow-up increased, "behavior-oriented treatments demonstrated promise in attaining long-term effects," write Stephen J. Tripodi, PhD, assistant professor in the College of Social Work at Florida State University in Tallahassee, and colleagues.

"To our knowledge, this is the first known meta-analysis to examine interventions aimed at reducing alcohol consumption in adolescents," they add.

"One of our aims as scholars is to bridge the divide between research and practice," Dr. Tripodi told Medscape Psychiatry. "There is a lot of valuable information here for clinicians who work in alcohol treatment centers for adolescents and for clinicians who have adolescent clients with alcohol problems. While we clearly understand the inherent flaws in the concept of evidence-based interventions, we support the steps included in the process of evidence-based practice."

The study is published in the January issue of Archives of Pediatric and Adolescent Medicine.

High Rates of Teen Alcohol Abuse

According to the study, alcohol is the most frequently used substance among adolescents. Previous research shows that less than 50% of 8th graders have used alcohol, whereas 50% of 12th graders reported ever being drunk, 30% reported participating in binge drinking, and 3% drank daily.

Furthermore, the study authors also note that adolescent alcohol use disorders are associated with serious psychosocial problems, including increased rates of comorbid mental health disorders and neurocognitive deficits, reduced motivation, and increased risk for subsequent adult alcohol abuse.

Currently, alcohol-decreasing interventions are divided into 2 primary formats — treatment provided directly to the adolescent or to the family.

Individual treatments commonly use behavioral interventions, cognitively oriented therapies, and/or motivational interviewing.

Although past trials have shown reductions in adolescent alcohol use across individual treatment approaches, most research has evaluated family-based interventions — with several trials demonstrating effectiveness, report the study authors.

"With multiple studies evaluating the effects of [these] interventions, synthesis across the studies is necessary to gain a clear picture of overall effects," they write.

Paucity of Research

Dr. Tripodi reported that before getting his PhD degree, he worked at several agencies that provided both individual and family treatment for substance-abusing juvenile delinquents.

"I noticed at the time that all interventions offered were based on either the administrators’ opinions or past experiences but not on their current clients’ personal experiences and not based on the literature.

"Furthermore, the association between alcohol abuse and [psychosocial problems] is troublesome, so we thought systematically evaluating the literature on interventions aimed at lowering alcohol use would be beneficial for clinicians," he said.

For the study, the investigators assessed and compared the effectiveness of individual- vs family-based interventions. They evaluated 16 studies (10 individual-based, 5 family-based, 1 using both) from 1994 to 2008. The studies included patients between the ages of 12 and 19 years who completed a substance abuse intervention aimed at reducing or eliminating alcohol consumption.

The primary outcome measure was abstinence, frequency of alcohol use, and quantity of alcohol use measured between 1 month and 1 year on treatment completion.

Overall results showed that the interventions significantly reduced the adolescents' alcohol use (Hedges g = −0.61; 95% confidence interval [CI], −0.83 to −0.40; P < .001).

In addition, stratified analyses showed larger effects for individual treatment (Hedges g = −0.75; 95% CI, −1.05 to −0.40) vs those that were family based (Hedges g = −0.46; 95% CI, −0.66 to −0.26).

The range of standardized effects for reducing alcohol use for individual treatments ranged from −0.09 (95% CI, −0.45 to 0.27) for brief motivational interviewing to −1.991 (95% CI, −2.37 to −1.61) "for cognitive-behavioral therapy integrated with the 12-step approach," report the study authors.

Other effective treatments showing large effect sizes (>0.80) included multidimensional family therapy, brief interventions with the adolescent, and brief interventions with the adolescent and a parent.

Surprise Finding

"Surprisingly, individual-only interventions had larger effect sizes, [which] contrast previous work that finds family-based interventions to be the ideal mode of treatment for adolescents with alcohol use disorders," the investigators write.

"Unequivocal claims that individual-based treatment is more effective are not, however, warranted, as potentially confounding factors were not controlled for in stratified analyses. Furthermore, both types of treatment were statistically significant, and many of the specific interventions for both modalities contained large effect sizes," they add.

Although investigators found an overall "increased chance that treatment participants returned to preintervention levels of drinking when there was a longer follow-up period," both behavior treatment and multidimensional family therapy showed significant reductions in alcohol use at 12 months after treatment.

"Considering that these interventions focus on altering maladaptive behaviors, it appears that behavior-based treatment, whether individual or family based, is beneficial in attaining long-term change," the study authors write.

Limitations of the study included differing follow-up lengths and inclusion criteria that were purposely narrow. In addition, the investigators did not stratify results based on different types of control groups, which prevented them from comparing effect sizes for standard treatment vs waiting list control groups.

"Because of some of the limitations of the study, we don't want readers to generalize the results beyond the 16 studies included in this analysis," added Dr. Tripodi.

The research team is now working on a similar project looking at the effects of interventions that aim to lower marijuana use. "Broadly speaking, more experimental designs need to be implemented when evaluating the effects of interventions for substance-abusing adolescents," said Dr. Tripodi. "This will allow further meta-analyses to pool studies for specific interventions and identical outcomes."

A Valuable Contribution

"This is the first meta-analytic review that I am aware of that looked at experimental and quasi-experimental studies on the effect of individually based and family-based interventions in this age group. I think it's promising that [the investigators] saw that there were 5 different types of interventions that showed some type of reduction in alcohol use," said Ralph Hingson, ScD, MPH, director of the Division of Epidemiology and Prevention Research at the National Institute on Alcohol Abuse and Alcoholism, Bethesda, Maryland. "This review is a valuable contribution to the literature."

However, Dr. Hingson, who was not involved with this study, cautioned that there are several questions that still need to be answered and pointed out that even the longest-term follow-up studies in this analysis did not go much beyond a year.

"Going forward, we need to ask: after one intervenes to try to reduce alcohol misuse among young people, in addition to short-term benefits, can this pattern of heavy drinking early on being associated with alcohol problems later in life be broken? I think that's the next research question that emerges from this particular study.

"Overall, I'd say this analysis is a positive step, and we hope it will continue to make progress," concluded Dr. Hingson.

The study was supported by a grant from the Donald D. Hammill Foundation. The study authors and Dr. Hingson have disclosed no relevant financial relationships.

Arch Pediatr Adolesc Med. 2010;164:85-91.

Clinical Context

Clinical Implications

• Sixteen percent of eighth graders report consuming an alcoholic drink in the previous 30 days. The comparative percentage among 12th graders is 44%, and 30% of 12th graders also report binge drinking. Alcohol use disorders in adolescents are associated with an increased risk for alcohol abuse during adulthood.
• The current meta-analysis suggests that all measured interventions reduced alcohol consumption by adolescents, including brief interventions. Individual-based treatment had a larger effect size compared with family-based interventions, and the treatment effect of interventions appeared to wane over time.

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