Depression has a chronic, episodic course marked by considerable social and academic impairment, substance use problems, tobacco use, high-risk sexual behavior, physical health problems, and increased risk of suicide.1,2,3,4 These sequelae account for a substantial proportion of the health care costs incurred by children and adolescents, and they are a significant economic and social burden to society.5,6 Particularly relevant to prevention is the fact that depression is quite recurrent. The majority of individuals with early-onset depressions experience another episode in their adult life,7,8 and most cases of recurrent adult depression have their initial onset during adolescence.9 Therefore, childhood and adolescence are particularly critical and opportune developmental windows during which to prevent the onset and recurrence of depressive disorders and associated problems.

As described in detail in earlier chapters in this volume, efficacious psychosocial and pharmacologic treatments for adolescent depression exist, but such approaches only help about 65% of those treated, and only about 25% of depressed youth ever receive treatment.10,11 Thus, despite potential benefits to individuals, society ultimately will be better off if depression can be prevented in the first place.12 Therefore, prevention of depression, particularly among high-risk youth, may be more cost effective and safe as well as less distressing for individuals than waiting for the condition to appear and then trying to treat a full depressive episode.

Historically, types of prevention were categorized as primary, secondary, or tertiary.13 Reducing the incidence of new cases of disorder in individuals who have not had the disorder was primary prevention, reducing the duration and severity of symptoms was secondary prevention (i.e., treatment), and reducing the recurrence of the disorder and its associated impairment in those who have already had it was tertiary prevention (maintenance).

The Institute of Medicine (IOM)14 found this distinction to be too broad and instead introduced the classification of prevention programs into universal, selective, and indicated, based on the population groups to whom the interventions are directed. Universal preventive interventions are administered to all members of a population and do not select participants based on risk. Selective preventions are given to subgroups of a population whose risk is deemed to be above average (e.g., offspring of depressed parents). Indicated preventive interventions are provided to individuals who have detectable, subthreshold levels of signs or symptoms of the disorder but who do not currently meet diagnostic criteria for the disorder. Thus indicated prevention may be considered early intervention for subclinical depression.

Some studies have included both selective (e.g., offspring of depressed parents; family conflict) and indicated (i.e., subsyndromal depressive symptoms) samples to identify a particularly high-risk group.15,16,17,18 Cuijpers19 suggested that high-risk samples are likely to have greater statistical power to detect a prevention effect because of the increased probability of finding disorder in the no intervention group. However, given the etiologic complexity of mood disorders, no single risk factor is likely to identify all individuals who will develop the disorder, and not all individuals who develop the condition will have that particular risk factor. Therefore, it might make sense to provide the intervention to individuals who have multiple risk factors, although the cost of screening to find such a sample may be prohibitive, and the results might not generalize. Offord et al. provided a more extensive discussion of the advantages and disadvantages of the different types of preventive interventions.20

A distinction has been made between prevention and treatment.21 Whereas a prevention effect is when there is little or no increase in symptoms in the intervention group relative to controls, a treatment effect is when a greater reduction in symptoms is found in the intervention group compared with controls. Most studies of depression prevention programs actually have found treatment rather than prevention effects.22

Mrazek and Haggerty14 argued that the term prevention should be reserved for “interventions that occur before the initial onset of a disorder” (p. 23) and not recurrence. Interventions that occur subsequent to a diagnosis of depression have been considered treatment rather than prevention.23 This distinction may simply be semantic, although both theory and empirical research suggest that different processes may underlie first versus subsequent depressive episodes,24,25 and therefore different types of interventions may be needed to prevent them.

Interventions can be conceptualized along a continuum from primary prevention of the first onset of symptoms and disorder in a universal sample, to preventing onset in selective at risk samples, to indicated prevention aimed at keeping subsyndromal states from becoming a full disorder, to prevention of recurrence of new episodes among individuals who already have had an episode, to treatment of individuals experiencing a current depressive episode that includes a relapse prevention component and maintenance.14 For an extensive discussion of the prevention of relapse and recurrence of depression in youth, see Kennard and colleagues.26

Are the essences of the interventions at these different points along the continuum the same, but in different doses, frequencies, and intensities, or rather are fundamentally different approaches to prevention and treatment needed? Thus far, there has been a tendency to start with existing treatments that have been efficacious in reducing symptoms in currently depressed adolescents—for example, cognitive behavior therapy (CBT), interpersonal psychotherapy (ITP)—and then translating them into prevention programs. Although a logical approach, it may not be the most efficient or effective strategy. Basic cognitive processes such as state-dependent learning and transfer of training may influence whether knowledge learned during a nondepressed state will generalize to the more affectively charged depressed state. Moreover, adolescents’ motivation to participate and learn depression prevention strategies when they are euthymic should be addressed early in the intervention. No matter what the content of a prevention program, any intervention with youth should be guided by a few basic principles: Keep it simple, keep it interesting, and make it relevant. These likely are the nonspecifics that are necessary although probably not sufficient.

Qualitative21,23,27,28 and quantitative22,29,30 reviews of studies testing interventions to prevent depression in children and adolescents have concluded that (1) some targeted (i.e., selective, indicated) depression prevention programs are efficacious; (2) the effects generally have been small to moderate; and (3) the effects tend not to endure. Most studies have measured change in depressive symptoms, which may be more accurately considered early intervention. Far fewer studies have prevented the subsequent occurrence of depressive disorders, and none has yet shown that the first onset of a mood disorder can be prevented.

The Society for Prevention Research (SPR) set forth an overlapping set of standards of evidence by which programs can be judged to be efficacious, effective, and appropriate for dissemination.31 SPR’s Standards Committee recognized that effective programs and policies are a subset of efficacious interventions, and interventions that are ready for dissemination are a subset of effective programs and policies. Table 20.1 outlines these criteria.

Table 20.2 summarizes the evidence of the efficacy of specific intervention programs aimed at preventing depression in youth. Six aspects of depression prevention programs in youth are summarized: (1) effect of the program assessed at postintervention, (2) effect of the program assessed at follow-up of at least 3 months’ duration, (3) replication of the program in at least two studies and replication by an independent research group, (4) whether diagnoses of depressive disorders were assessed, (5) sample size greater than 100 participants, and (6) whether some form of adherence/fidelity was assessed.

Clearly the Penn Prevention Program (PPP)17,32 has been tested most extensively with universal, selective, and indicated samples, has shown both short- and long-term significant effects, and has been replicated multiple times and by independent researchers. Most studies of PPP have assessed depressive symptoms, although a few have included evaluations of depressive disorders. Samples sizes have been generally adequate, and evidence of satisfactory fidelity has been demonstrated.

The second most replicated depression program is the Coping with Depression Course developed by Clarke and colleagues.33 Short-term efficacy was found when tested in a universal sample, and both short- and long-term efficacy have been found in selective and indicated samples. Significant effects have been replicated by independent researchers, depressive diagnoses have been assessed, sample sizes have been generally adequate, and adherence to the program protocol has been found.

The Resourceful Adolescent Program (RAP)34,35 has been tested in large universal samples, found to be efficacious both at postintervention and follow-up, replicated by independent researchers, and




found to have satisfactory adherence. Given the large sample sizes, it is not surprising that diagnoses of depression have not been assessed.