Development, Testing and Implementation of a Physical Activity Intervention for Youth With Anxiety and Depression -Confident, Active and Happy Youth

In order for health authorities to be able to respond to the current high demand on mental health services in youth, current treatment interventions need to be examined. The need for augmented and/or supplementary interventions is pressing. Physical activity appears to be a promising, low-risk intervention that may serve this purpose and provide long-term protective health benefits. Despite the potential gain from including physical activity in CAMHS treatments, to our knowledge, no previous study has examined the use of a physical activity program in CAMHS as a supplementary treatment in youth's with anxiety and/or depression. Furthermore, there is a paucity of studies of high methodologically quality examining this topic.

It is the aim of the current study to address this shortcoming by developing a theoretically based physical activity intervention to supplement existing treatment for youth with internalizing disorders (Confident, Active and Happy Youth: CAH-Y).

The current research and intervention development will be based on the UK Medical Council Research Framework (MRC) for developing and evaluating complex interventions.

The MRC framework strongly recommends carrying out feasibility testing prior to any full-scale trial. In line with this recommendation and phases, one and two of the MRC framework, this study proposes to develop and examine the feasibility of recruitment, retention and acceptability of a physical activity intervention for youth with anxiety and/or depression treated in CAMHS. This work will lay the groundwork for later phases and a definitive RCT.

Methods Development of the intervention The theoretical framework for the CAH-Y intervention will draw on three theories. While not a unified theory, the evidence on the psycho-physiological effect of moderate to vigorous physical activity in regards to mood and anxiety disorders in youth specifically and youth mental health in general, indicates a plethora of causal pathways and positive effects. Primarily modulation of monoamines (e.g., increase in serotonin levels), and HPA axis regulation are assumed to be of importance in relation to anxiety and depression. Secondly, Self Determination Theory is a framework with which to understand participant experiences with physical activity and their motivation towards physical activity. The framework focuses on intervention components that can enhance learning and intrinsic motivation concerning both increased activity and behaviour and symptom change. Regarding motivation, evidence suggests that in order to establish physical activity behaviour change, individuals must be either in the 'preparation' or in the beginnings of an 'action' stage of change. Thus, in order to increase physical activity, it is critical that participants are engaged and ready to change behaviour. The final theoretical foundation is inhibitory learning theory which provides a generic framework to understand the bi-directional interaction between cognition, affects and behaviour in regards to anxiety and depression and in particular the role of (physical activity) avoidance as a contributor to and a maintaining factor in these disorders.