Whole of Diet Approaches to Mood and Mental Health: Exploring Dietary Patterns and Depression using an Integrated Approach
Creators: name: Lee, Megan
Publisher: name: Southern Cross University
Year: 2021
Subjects: subject: Dietary patterns
subject: Depression
subject: Nutrition
subject: Psychology
subject: FOS: Psychology

description: Over 300 million people worldwide experience the symptoms of depression. Depression is a chronic, complex and multifactorial condition. While psychotherapy and psychopharmacology are the most common treatment options, they are believed to be effective in just one-third of people experiencing symptoms. Nutritional psychiatry research explores dietary patterns as an adjunct treatment alongside these options. However, this evidence largely consists of observational research and conflicting findings across meta-analyses and systematic reviews. This thesis uses a convergent parallel mixed-methods design encompassing three studies to address the overarching research question: Is there a relationship between dietary patterns and depression in adults? The first study, an umbrella review of all meta-analyses and systematic reviews found that while many studies reported an association between dietary patterns and depression risk, the certainty of the body of evidence was very low due to high levels of measurement error, heterogeneity, and reliance on observational findings. The second study, a secondary analysis of the Australian Longitudinal Study on Women’s Health (ALWSH) data found a small, significant inverse association between diet quality on depressive symptoms after adjusting for covarying factors such as social functioning, physical activity levels, geographical location, alcohol and smoking status, marital status, body mass index and education. Finally, a qualitative focus group study using thematic template analysis exploring individuals’ experiences with food and mood uncovered four themes: (i) Food in Society and Related Social Economics, (ii) Reactive and Proactive Relationships with Food, (iii) Acknowledgement of Individual Diversity Relating to Eating and Mental Health, and (iv) Improving Mood by Removing Food Restriction and Eating Intuitively. The overall synthesis of the thesis suggested four key outcomes: (i) Quality and Diversity of Healthy Food and the Relationship with Mood (ii) The Link Between Food in a Social Context, Dietary Patterns and Depressive Symptoms, (iii) Population-Based Dietary Guidelines, Biodiversity and Mixed Nutrition Messages, and (iv) The Role of Food Restriction, Negative Relationships with Food and Body Image in Mental Health. Limitations within the thesis include: the inability to correct for differing depression terminologies and measurement error common in nutritional psychiatry research. The findings may not be generalisable to a population of people who eat a traditional Western dietary pattern. Despite these limitations, overall results suggest that evidence supports the theory that there is a relationship between dietary patterns and depression, however, more intervention and longitudinal studies are needed to assess for causal and temporal effects and clinical significance.