Alcohol is the drug of choice for adolescents, with cigarettes and marijuana being second and third.1 Contrary to widespread belief, alcohol(Drug information on alcohol) dependence is most common in 18- to 20-year-olds, with progressively decreasing rates of alcohol dependence in older age groups.2 Similarly, the age at onset of alcohol dependence is typically highest among those in their later teen years and early 20s, with a much lower rate of onset after the age of 25 years.2
Comorbidity, particularly with major depressive disorder (MDD), is the rule rather than the exception in young people.3 Alcohol use disorders (AUDs), including alcohol dependence and alcohol abuse, and MDD co-occur more frequently than would be expected by chance alone. A number of studies have shown an even stronger association between AUDs and comorbid MDD in clinical samples of adolescents and young adults than in community samples.4
AUDs also commonly co-occur with bipolar disorder. Bipolar disorder can present as either depression, mania, or a combination of depression and mania, so care must be taken to distinguish between major depression and bipolar disorder when an adolescent presents with depressive symptoms.CLINICAL PRESENTATION
The depressive symptoms of adolescents with comorbid AUD and MDD are similar to those of adults. The acute clinical presentation in adolescents tends to focus on depressive symptoms, while chronic difficulties--including social and health problems--typically result more often from AUDs. Adolescents typically drink less frequently but more heavily than adults.5 Adults with comorbid AUD and MDD demonstrate a much higher rate of suicidal indicators than either single-diagnosis comparison group (AUD or MDD alone).6 Adolescents in whom comorbid disorders have been diagnosed are at a higher risk for attempting suicide.7 Among those with comorbid disorders, suicide attempts are most common following a recent period of very heavy drinking.8Clinical course and prognosis
Birmaher and colleagues9 concluded that for most children and adolescents, the index episode of MDD is the beginning of a chronic, recurrent, lifelong disorder. They also found that major depression among children and adults is usually accompanied by other disorders, and continued treatment is generally needed to prevent recurrences of major depression. Similarly, Emslie and coauthors10 reported that 40% of the adolescents they studied with MDD (with no comorbid drug use or AUD) suffered a recurrence of major depression within 12 months of successful treatment with fluoxetine(Drug information on fluoxetine), which they concluded was a higher rate of recurrence of depression than is generally noted among adults.
Cornelius and associates11 undertook a follow-up study of adolescents with comorbid AUDs in combination with major depression and found a high rate (80%) of recurrence of depression in the 5 years following acute-phase treatment with fluoxetine. Thus, it appears that adolescents with major depression display a higher rate of recurrence of major depression than do adults and that adolescents with comorbid disorders display a higher risk of recurrent depressive episodes than do adolescents without comorbidities.
Rapid relapse to alcohol and other substance use has been shown to generally occur following treatment for alcohol and other substance use disorders (SUDs) among adolescents, with two thirds of adolescents relapsing to alcohol or drug use within 6 months after treatment.12 Major depression comorbidity has been shown to be associated with earlier relapse to alcohol and other substance use in adolescents.13 However, the level of substance use typically declines somewhat in the year following treatment.14 Preliminary data from a small sample suggest that the long-term prognosis for adolescents with an AUD and a comorbidity may be better than that for adults with an AUD and a comorbidity.11 A high degree of heterogeneity characterizes adolescents' courses after treatment, involving multiple trajectory subgroups.14 Thus, the long-term course of depressive symptoms and alcohol use in adolescents with comorbidities is variable, but often problematic, so longer-term treatment is warranted--particularly for adolescents with significant residual symptoms.SCREENING AND ASSESSMENT
Adolescents with major depression should be routinely screened for the presence of alcohol and other SUDs, and conversely, adolescents with an AUD should be routinely screened for the presence of major depression because of the high levels of co-occurrence of those disorders. If an SUD or AUD is detected on initial screening, then a follow-up urine drug screening and Breathalyzer or other measure of blood alcohol concentration should also be considered. As noted above, the comorbid presence of an SUD and major depression is often associated with suicidal ideation or suicidal behavior, so assessment of suicidality should be routine clinical practice if an SUD or major depression is noted.6-8 If these conditions are detected during screening, then appropriate referral should be made for further evaluation and subsequent treatment.