- Title
- A randomised trial of an integrated motivational interviewing and exercise intervention among youth with major depression: differential treatment effects on depressive symptom profiles and associated factors
- Creator
- Nasstasia, Yasmina
- Relation
- University of Newcastle Research Higher Degree Thesis
- Resource Type
- thesis
- Date
- 2020
- Description
- Research Doctorate - Doctor of Philosophy (PhD)
- Description
- Major depressive disorder (MDD) is a heterogeneous disorder with a diverse symptom profile. MDD is a growing public health problem across the world that shows no sign of abating in reach or impact to the individual and to society. In recent decades, numerous meta-analytic reviews have documented the beneficial effects of exercise for depression among adult populations; however, there is insufficient evidence to determine if this efficacy extends to young people with MDD. Additionally, very little is known about any differential treatment effects of exercise interventions on depressive symptom profiles (cognitive, affective, somatic symptoms) and other cognitive, behavioural and physiological factors. This represents a significant gap in the literature, as this knowledge may help identify how exercise exerts its therapeutic effects and who may benefit from treatment based on their symptom profile. Another issue that has received less attention and constrains findings are the variable rates of engagement with exercise programs among individuals with MDD. Motivational interviewing (MI) has been successfully applied as a prelude intervention to help increase engagement with a range of interventions; however, little is known about the benefits of integrating MI with exercise among youth with MDD. To address these important gaps in the literature the primary aim of this thesis was to investigate the effects of an integrated motivational interviewing (MI) and exercise intervention on depressive symptom profiles (cognitive, affective, somatic symptoms) and other associated cognitive, behavioural and physiological factors among youth (aged 15-25 years) with MDD. The secondary aim of this thesis was to evaluate the feasibility, fidelity and engagement effects of a newly developed MI intervention designed to enhance engagement with exercise programs, and assess any role it may play in enhancing exercise readiness and self-efficacy. The research program set out in this thesis is comprised of a series of six chapters detailing four chronological studies (published papers) that address the primary and secondary aims of this thesis. Study one, presented in Chapter two, was a pilot study that demonstrated the beneficial effects of exercise for depression among young people diagnosed with MDD, with differential treatment effects of exercise on depressive symptom profiles observed. The pilot study found significant improvements in associated cognitive and behavioural factors, as well as a link between increased behavioural activation and improvement in inflammation. Outcomes from the pilot study showed integrating MI with exercise was feasible, with strong engagement effects observed. Study two, presented in Chapter three, outlines the study protocol for the HBHM randomised controlled trial (RCT) and methodological revisions based on pilot work. This included modifications to the MI protocol, the rationale for these changes and the inclusion of additional outcome measures to further assess the effects on cognition and physical (somatic) health symptoms. Study three, presented in Chapter four, details the primary outcomes from the RCT. This study confirmed the beneficial effects of exercise for depression among young people diagnosed with MDD with differential changes in depressive symptom profiles documented in the pilot study. The RCT also recorded significant improvements in associated cognitive and behavioural factors and improvements in fitness were significantly associated with improvements in depression post-treatment. Similar to the pilot study, maintenance effects of exercise at follow-up were also observed. Study four, presented in Chapter five, pooled data from the pilot study and the efficacy phase of the RCT. Outcomes showed strong engagement effects with approximately 96% of the participants commencing the exercise program. Improvements in stage of change (exercise readiness) and self-efficacy post MI were also observed and this had beneficial effects on subsequent exercise participation. This series of studies provided evidence that exercise as treatment for depression is a promising, cost effective and accessible treatment option that warrants further research. The overall conclusions from these studies shows exercise is efficacious for treating depression in young people, with efficacy effects driven by improvements in negative self-concept and activation. This finding is further supported by concurrent improvements in associated cognitive, behavioural and physiological factors as well as their interrelationships with physiological and biological factors. The findings from this research program also showed integrating MI with an exercise intervention was feasible, with good fidelity and engagement effects observed. Prelude MI increases exercise readiness and self-efficacy and this contributes to exercise adherence. Taken together this research program extends existing knowledge and addresses important gaps in the literature. The clinical implications of these findings, limitations and directions for future research are discussed.
- Subject
- exercise; depression; affective; cognitive; somatic; youth; thesis by publication
- Identifier
- http://hdl.handle.net/1959.13/1414057
- Identifier
- uon:36696
- Rights
- Copyright 2020 Yasmina Nasstasia
- Language
- eng
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| Thumbnail | File | Description | Size | Format | |||
|---|---|---|---|---|---|---|---|
| View Details Download | ATTACHMENT01 | Thesis | 5 MB | Adobe Acrobat PDF | View Details Download | ||
| View Details Download | ATTACHMENT02 | Abstract | 441 KB | Adobe Acrobat PDF | View Details Download |