In this chapter, we describe the intervention classifications and the components used in the NMAs reported in Chapters 4 and 5.
Main ‘intervention-level’ classification
The main ‘intervention-level’ classifications were assigned based on the trial authors’ descriptions and classifications used in previous systematic reviews.36–39,68,108–113 Many interventions to prevent anxiety and depression have been adapted from existing clinical interventions for treatment which, in turn, are grounded in identifiable therapeutic traditions. In adapting therapeutic interventions for a prevention context, some developers have retained the reference to the underlying therapy on which they are based, for example cognitive–behavioural therapy. Although these preventative interventions focus on the same techniques, exercises and skills that underpin the clinical ‘therapeutic’ intervention, the term ‘therapy’ may be considered a misnomer in a preventative context. As such, it may be preferable and more accurate to consider these preventative interventions as ‘interventions based on the principles of CBT’. However, for conciseness and consistency with the trial literature we retain the use of ‘therapy’ when using intervention abbreviations throughout the report (e.g. CBT).
Behavioural therapy
Behavioural therapy is a group of allied techniques that focus on behavioural models of psychology and seek to modify overt maladaptive behaviours. In the current review, we categorised interventions based on behavioural activation, self-monitoring, role-playing, exposure to feared stimuli or scheduling pleasant activities as being behavioural in nature.
Cognitive–behavioural therapy
Cognitive–behavioural therapy can be considered a family of allied techniques, based in both behavioural and cognitive models of psychology, that utilise a set of overlapping cognitive and behavioural techniques. CBT is based on the proposition that a person’s behaviour is influenced by their cognitive activity (and vice versa), and that cognitions can be monitored and altered (cognitive restructuring). In turn, emotions and behaviour can be modified via this cognitive change. CBT interventions for treatment of CMDs typically include a psychoeducation component; however, in preventative interventions, this may not always be present.
Third-wave interventions
This was a composite category. Third-wave psychotherapies emphasise mindfulness, acceptance and flexibility. They tend to focus on a person’s relationship to their cognitions and emotions, encouraging an acceptance of thoughts, rather than modifying their content. Interventions that described themselves as mindfulness-based CBT, acceptance and commitment therapy or dialectical behavioural therapy were included in this classification. Third-wave preventative interventions were distinguished from mindfulness meditation or relaxation interventions that did not explicitly address cognitions or behaviours.
Interpersonal therapy
From a treatment perspective, interpersonal therapy (IPT) is based on the relationship between mood symptoms and interpersonal relationships. It seeks to relieve symptoms via resolving interpersonal conflict and difficulties. In the preventative context, IPT addresses the relationship between young people significant adults (e.g. teachers, parents), with regard to avoiding/resolving conflict via improved coping communication skills. The techniques used attempt to improve interpersonal skills may include role play, problem-solving exercises and practising effective communication.
Mindfulness meditation and relaxation-based interventions
In the present review, mindfulness/relaxation is a composite category and is distinct from third-wave interventions. Relaxation includes breathing exercises, muscle relaxation and yoga from the Iyengar or Hatha traditions (as opposed to more vigorous traditions). Mindfulness meditation interventions were included in this category if they focused solely on meditation or relaxation without incorporating aspects of traditional ‘talking’ psychotherapeutic approaches.
Biofeedback
Biofeedback is a mind–body intervention that uses physiological monitoring devices or equipment to learn to control physiological responses, such as heart rate. Users may monitor their heart rate variability using pulse oximetry, for example while completing a standard deep-breathing exercise. The feedback received helps the participant learn how to influence the negative, or undesired, response (e.g. a stress response). Smartphone applications and ‘consumer wearables’ have been developed for monitoring stress, anxiety and sleep problems.
Exercise
In this review, we classified an exercise intervention as a cardiovascular intervention designed to raise heart rate and breathing to (at least) a moderate intensity level, for example dancing, running and team sports.
Cognitive bias modification
Cognitive bias modification (CBM) relates to a group of approaches, including attention and interpretation bias training, that aim to retrain cognitive distortions. CBM evolved from a visual attention task (a dot-probe task), in which a participant is exposed to a series of threatening and neutral stimuli via computer, such as angry and neutral faces, and the speed of their response to a ‘probe’ is measured (e.g. where on the screen the angry or neutral face was displayed). In individuals with a CMD, attention tends to be selectively directed towards the negative image and response times to the probe are slower. CBM for the treatment of anxiety disorders seeks to ‘retrain’ this selective attention bias towards the positive stimulus. In preventative interventions for CYP, CBM tasks may be embedded in engaging and user-friendly formats such as interactive video games (‘CBM gamification’).
Occupational therapy
Occupational therapy interventions are based on engaging CYP in meaningful daily activities or ‘occupations’. Interventions are skill based and aim to enable CYP to successfully engage with, and participate in, developmentally appropriate everyday events. For example, an intervention might focus on a favourite activity to increase self-esteem, or schoolwork may be modified to create a positive learning environment and reduce stress.
Control groups
On the basis of previous research,68,72–74 we distinguished the following separate control groups. We note that, in the included trials, psychoeducation and psychosupport were sometimes considered as active interventions in their own right. Their inclusion under a ‘control group’ heading does not affect the findings.
Psychoeducation
Often a component of CBT-based interventions, psychoeducation can also be used as a distinct intervention. It typically involves a systematic approach to providing background information, for example what the cause or symptoms of a mental disorder are and advice regarding the mental disorder and/or explaining the approaches that can help to mitigate symptoms. Written materials or presentations may be provided.
Psychosupport and counselling
Often a component of other interventions, psychosupportive interventions are also used in a stand-alone format. In the current report, we combined psychosupportive and counselling-based interventions into one category. Here it refers to a non-specific, possibly therapeutic, intervention that could include listening, signposting to further services, or forming an attachment or therapeutic alliance.
Usual curriculum
If an active intervention took place during a regular timetabled class and participants in the control group continued to receive the regular class curriculum, the control intervention was classified as standard provision or ‘usual curriculum’. This included a variety of different classes and could have included a ‘well-being’ or health lesson or a standard timetabled academic lesson (such as history or mathematics).
Waiting list
If participants in the control group were explicitly told (e.g. via informed consent processes) that they would receive the active intervention at a later date, the control condition was categorised as a waiting list. Although participants were also likely to be receiving usual curriculum or a no-intervention control, the use of an explicit waiting list design takes precedence in our categorisation.
No intervention
A no-intervention control categorisation was used to differentiate between a control condition in which participants received something and a control condition in which participants were not involved in any structured activity. This classification was applied when the active intervention was held outside regular timetabled classes (e.g. after school) and the participants were not described as being in a waiting list control.
Attention control
A control was classified as attention control if it was a de novo intervention provided to the participants for the purpose of the research study.
Component classifications
As described in Chapter 2, ICA is a subjective process. We defined an intervention component as a potentially active ingredient or constituent part of a main ‘therapy-level’ intervention. In a NMA, components can be included as indicator variables in a network metaregression; as such, they are pragmatic classifications related to the techniques used, and may not pertain to psychotherapeutic schools or traditions. We did not assume the presence of a component based on the therapy-based intervention-level classification assigned by study authors, but on the details provided about what was done. For example, if an author stated that the intervention was CBT based, we did not assume that it contained a psychoeducation, cognitive or behavioural component unless it was clearly stated in the paper (or intervention manual if applicable). We coded only what was clearly reported, and discuss this further in the limitations section of the discussion (see Chapter 10).
Component classifications should also be read independently from the similar-sounding main intervention-level classifications mentioned previously. For example, an intervention-level CBT classification may be defined by the following illustrative combinations of components, depending on what was reported:
CBT intervention 1 – psychoeducation + cognitive + behavioural + relaxation + exercise
CBT intervention 2 – cognitive + behavioural
CBT intervention 3 – psychoeducation + cognitive.
Behavioural
A behavioural component was one in which techniques included helping participants to practise and acquire new skills to cope or manage difficult emotions, moods or behaviours. This component includes strategies used in behavioural activation, social skills exercises (including how to make friends, be a good friend and support your friends), role play, assertiveness training, interpersonal work and activity scheduling and contingency management including goal-setting, planning and decision-making activities, problem-solving and exposure. Following Hetrick et al.,68 this component was initially subdivided into four further subcomponents: (1) social skills training, (2) problem-solving, (3) exposure and (4) ‘other’ behavioural categories. However, this resulted in unconnected networks, so results are reported for a ‘lumped’ behavioural component only.
Cognitive
This component label was applied when an intervention included strategies or techniques designed to identify and replace cognitive distortions with more accurate and adaptive ones, for example recognising and understanding thoughts and feelings, using positive self-talk and challenging negative self-talk and thoughts.
Third wave
During the ICA, we observed that standard CBT, third wave interventions and mindfulness/relaxation interventions were often based on combinations of the same components. We included a third wave component category to ensure differentiation between these ‘therapy-level’ interventions. The component definition is the same as described previously for the intervention level analysis.
Mindfulness
Mindfulness techniques included guided meditation, colouring and drawing, and exercises to practise being in the moment and being free from judgemental thoughts and distractions. On completion of the component coding, we observed that a mindfulness component was always present in conjunction with a relaxation component.
Relaxation
Separate mindfulness and relaxation components were specified to allow for relaxation techniques that were not defined as meditation or mindfulness. This included strategies such as progressive muscle relaxation, abdominal breathing exercises, cue-controlled relaxation, and identification of physiological arousal (‘body clues’) approaches.
Physiological
A component was coded as physiological if it involved the process of displaying involuntary or subthreshold physiological processes, usually by electronic instrumentation, and learning to voluntarily influence those processes by making changes in cognition.
Bias modification
This component was present only in the main therapy-level intervention, CBM, as described previously. However, on completion of coding, it was retained as a separate component, as the four studies that could be described as evaluating a CBM intervention were assessed as containing different combinations of components:
study 1
114 – bias modification
study 2
115 – behavioural + relaxation + physiological + bias modification
study 3
116 – behavioural + physiological + bias modification
study 4
117 – cognitive + bias modification.
Psychoeducation
Psychoeducation was also included as a component of broader interventions. The definition applied at the component level is the same as described previously for the intervention-level analysis.
Additional process and implementation classifications
We also extracted information on the following implementation and process components of interventions: number of sessions, duration of intervention (minutes), mode of delivery (face to face or digital), group or individual delivery, who the facilitator was and whether or not training was provided, and whether or not intervention fidelity was monitored. The characteristics of interventions, the components and process details are provided in Chapters 4 and 5 and in Appendix 2. We did not include the process components in the NMA owing to concerns regarding a lack of power and network connectedness.82
