Substance-Abusing Adolescents Show Ethnic and Gender Differences in Psychiatric Disorders

NIDA researchers have found that the patterns of co-occurring psychiatric disorders in adolescent substance abusers differ between ethnic groups and between boys and girls. This information may help clinicians be particularly alert to symptoms of the most common psychiatric disorders when interviewing patients from each group. Eventually, it may aid in the development of tailored screening, assessment, and treatment interventions for different groups.

Typical Behaviors in Adolescent Psychiatric Disorders

Ethnic Differences

Dr. Michael Robbins and colleagues from Florida's University of Miami found high rates of psychiatric disorders among Hispanic and African-American adolescent substance abusers referred for outpatient therapy. Their study distinguished externalizing disorders--characterized by lack of self-control and acting-out behaviors, recurring patterns of aggression, and behaviors that prevent the development and maintenance of relationships--from internalizing disorders, typified by sadness, withdrawal, avoidance of interaction with others, and loss of interest in activities.

"Studies have consistently documented high rates of psychiatric disorders among adolescent substance abusers. They also have found that certain co-occurring disorders are associated with certain treatment outcomes. For example, depression or attention-deficit/hyperactivity disorder (ADHD) may contribute to early dropout and poor treatment outcomes," says Dr. Robbins. "Therefore, treating substance abuse alone may not be enough. Treatment providers need to address the constellation of emotional and behavioral problems presented by each individual."

The researchers recruited 167 Hispanic and African-American 12- to 17-year-olds referred for outpatient treatment for substance abuse between October 1997 and March 2000. Participants' substance use was assessed before treatment with the Adolescent Drug Abuse Diagnosis, a standard assessment tool that provides information on the frequency of use of alcohol, marijuana, cocaine, and other drugs during the preceding month. The youths also completed the Diagnostic Interview Schedule for Children--Predictive Scales, a questionnaire that screens for nine psychiatric disorders, including social phobias, panic, anxiety, major depression, ADHD, oppositional defiant disorder (ODD), and conduct disorders (CD).

Dr. Robbins and colleagues found that Hispanic and African-American youths were similar in the drugs they used and their overall prevalence of co-occurring psychiatric disorders. More than 80 percent of the participants reported using marijuana, and about 17 percent and 35 percent reported using cocaine and alcohol, respectively. Overall, 87 percent of the youths reported symptoms of at least one co-occurring psychiatric disorder. Of these, about 19 percent reported symptoms for only one disorder, while more than 54 percent reported symptoms of three or more disorders.

Hispanic youths had significantly more symptoms of externalizing psychiatric disorders, such as ADHD and ODD, than did African-American youths. More than 78 percent of Hispanics reported symptoms of at least one externalizing disorder, compared with about 65 percent of African-American youths. However, about twice as many African-American adolescents reported symptoms for agoraphobia, an internalizing psychiatric disorder that finds the sufferer severely anxious about going outside the home. The researchers note, though, that the high rates of symptoms associated with agoraphobia may instead reflect legitimate fears about being in very dangerous public settings.

"Our findings suggest that substance abuse among Hispanic youths may occur more often within a larger context of problem behaviors," says Dr. Robbins. In addition to enhancing Hispanic youths' emotional and behavioral functioning, interventions need to address problems with their families, schools, peer group, and other areas where co-occurring externalizing behaviors often have severe and profound consequences."

Dr. Robbins observes that his findings may be relevant primarily to youths referred for outpatient treatment, rather than all Hispanic and African-American substance-abusing youths. "We believe substance abuse among African-American youths may be related to problem behaviors as well. Our sample drew from community outpatient referrals. Further research is warranted to determine if there is a basic difference between ethnic groups in the constellation of behavior problem symptoms or if our numbers reflect a bias in the way youths are referred to outpatient treatment. African-American youths may be more likely to be referred to other types of treatment providers or sent to jail or detention."

Co-Occurring Psychiatric Disorders Vary by Ethnicity and Gender in Adolescent Substance Abusers (by Percent)

^a Robbins et al., Journal of the American Academy of Child and Adolescent Psychiatry, 2002. Percentages indicate a probability estimate of the presence of psychiatric disorders.
^b Latimer et al., Experimental and Clinical Psychopharmacology, 2002.
^c Data not available.

Among substance-abusing youths referred for outpatient substance abuse treatment, Hispanics reported higher rates of externalizing disorders than did African Americans, while African Americans reported higher rates of the internalizing disorder agoraphobia. In a separate study of adolescent substance abusers, boys were more likely to be diagnosed with externalizing disorders, while young women were more likely to be diagnosed with depression, an internalizing disorder.

Gender Differences

Dr. William Latimer and colleagues at the Johns Hopkins University, Bloomberg School of Public Health, in Baltimore, and the University of Minnesota, Twin Cities, Minneapolis, examined gender differences in rates of co-occurring psychiatric disorders in substance-abusing adolescents. They found that more male teenage substance abusers also had disruptive disorders, whereas females had higher rates of depression.

"Gender may be useful in helping clinicians who assess youths referred to drug treatment by signaling the likely presence of certain psychiatric disorders for males and females. However, clinicians should not rule out the possibility of a disorder based on the patient's gender." says Dr. Latimer. "For example, although co-occurring disruptive disorders are more common among males than females, this shouldn't obscure the equally important finding that high rates of these disorders are also present among substance-abusing females."

The researchers recruited 135 adolescents (ages 12 to 19) who met the Diagnostic and Statistical Manual of Mental Disorders criteria for one or more psychoactive substance use disorders (PSUD), including alcohol abuse or dependence, marijuana abuse or dependence, and abuse or dependence on drugs other than alcohol and marijuana. Adolescents and their parents completed the Diagnostic Interview of Children and Adolescents, which provided information about PSUDs and symptoms of ADHD, ODD, CD, and mood disorders. Adolescents also completed the Personal Experience Inventory, which provided information about 3-month, 12-month, and lifetime alcohol and other drug use frequencies and related consequences. Adolescents' reports of substance abuse were verified by urine tests.

About 68 percent of the girls and 75 percent of the boys were diagnosed with alcohol abuse or dependence, while about 85 percent of the girls and 93 percent of the boys were diagnosed with marijuana use disorders. More than 17 percent of the girls and 21 percent of the boys were diagnosed with abuse or dependence on some other drug or drugs. The patterns of single-substance versus polysubstance use also varied with gender. Girls were more likely to be diagnosed with abuse or dependence on only one drug, while boys were more likely to be diagnosed with simultaneous abuse or dependence on more than one drug.

The researchers found that nearly twice the percentage of teenage male substance abusers had co-occurring ADHD or CD compared with female teen abusers, whereas roughly three times the percentage of females had a co-occurring major depressive disorder. However, both genders had similar rates of mild depression (dysthymia), double depression (chronic depression with episodes of major depression), and bipolar disorders.

"Drug abuse and psychiatric disorders co-occur at extremely high rates in adolescents," says Dr. Latimer. "Therefore, drug treatment programs may be more effective if strategies that address multiple patterns of simultaneously occurring disorders are included. Those geared toward adolescent boys may benefit by incorporating strategies that address psychiatric problems related to behavioral dysfunctions, while those intended for adolescent girls may need to include therapies that address major depression." Further examination of how simultaneously occurring psychiatric and substance abuse disorders interact is needed, he notes.

"When a group of patients shares a characteristic, such as age or gender, it seems reasonable to expect that they might require a treatment sensitive to that characteristic," says Dr. Melissa Racioppo of NIDA's Behavioral Treatment Development Branch. "But it is also possible that a characteristic may be irrelevant to treatment outcome. Drs. Robbins' and Latimer's studies help identify characteristics of groups of substance abusers, which lays the groundwork for testing the relevance of these characteristics to treatment interventions. In the future, we may have effective behavioral treatments that appropriately attend to gender and racial/ethnic differences among adolescent substance abusers."

Sources

• Latimer, W.W., et al. Gender differences in psychiatric comorbidity among adolescents with substance use disorders. Experimental and Clinical Psychopharmacology 10(3):310-315, 2002.
• Robbins, M.S., et al. Ethnic differences in comorbidity among substance-abusing adolescents referred to outpatient therapy. Journal of the American Academy of Child and Adolescent Psychiatry 41(4):394-401, 2002.