Core elements of Cognitive Behavioral Therapy in preventing depression in youth:
Does the type and sequence of elements matter?

Depression during adolescence is a major public health concern, because of its
high prevalence, association with suicide, co-morbid psychiatric diagnoses and
high treatment costs. Even sub-clinical levels of depressive symptoms put
adolescents at risk for several negative outcomes. Therefore, it is important
that depression is detected at an early stage and is treated preventively.
Prevention programs based on the principles of Cognitive Behavioral Therapy
(CBT) have proven to be the most effective and most applied in preventing
depression among adolescents. Thus far, research has mainly focused on
effectiveness of *prevention packages* consisting of multiple CBT-elements.
Most common CBT-elements in existing programs are cognitive restructuring,
behavioral activation, relaxation and problem solving skills. It is unclear
which of these elements contribute to the positive prevention outcomes and how
these elements should be offered (i.e., what their optimal sequencing is). This
study proposes to evaluate the differential (cost-)effectiveness of different
types and sequences of CBT-elements in the prevention of depression among
adolescents.

The primary objective is to investigate whether (and if so, which) type of
CBT-element (cognitive restructuring (CR), behavioral activation (BA),
relaxation (RE) and problem solving skills(PS)) is relevant for the positive
effect of CBT-programs on the level of depressive symptoms in adolescents. The
secondary objective is to investigate whether (and if so, which) sequence of
CBT-elements is relevant for the positive effect of CBT-programs on the level
of depressive symptoms in adolescents. In addition, it will be explored for
whom (i.e., moderation) and how (i.e., mediation) a given element, or set of
elements, is most effective. Besides, the cost-effectiveness of the prevention
of depression will be investigated.

A Randomized Controlled Trial with four conditions (all prevention programs).

The prevention program will be developed by the researchers themselves in close
collaboration with experts and CBT-therapists. The program will be designed as
a Cognitive Behavioral Therapy, a therapy which has proven to be effective. It
will consist of twelve weekly sessions, each 45-60 minutes long. Prior to the
training an introductory meeting will take place, which lasts 30 minutes. For
each of the four CBT-elements a module of three sessions will be developed.
Each condition starts with a different module and contains a different sequence
of modules (condition 1: CR, BA, RE, PS; condition 2: BA, CR, RE, PS; condition
3: PS, BA, CR, RE; condition 4: RE, PS, BA, CR).
The prevention program will be given in same-sex groups consisting of six to
eight participants. It will be provided by certified alumni pedagogy and
psychology, who will trained and supervised by certified CB- therapists.

The potential value of the study is that we gain insight in the differential
effectiveness of the four most commonly used CBT-elements in the prevention of
depression among adolescents, and in their most optimal sequence. This
knowledge can be used for recommendations to optimize CBT-programs in the
prevention of adolescents with depressive symptoms. Possible direct benefits of
participating in this study, is that we offer adolescents with elevated levels
of depressive symptoms an effective program to prevent them from becoming
severely depressed. As an indirect positive effect, suicide can possibly be
prevented. A direct burden for the participating adolescents is that they have
to fill out questionnaires, will be interviewed and have to attend treatment
sessions. However, in our opinion this burden outweighs the possible benefits
of less depressed adolescents and a lower suicide risk.