Celiac disease is an immuno-mediated pathogenesis disease characterised by a malabsorption of nutrients that causes partial or total atrophy of intestinal villi and the alteration of the absorbing epithelium. Several studies have demonstrated the presence of anxiety and depression symptoms and poor quality of life in people with celiac disease and emphasised the importance of diet in modulating these effects. However, few studies have investigated the role of motivation and the relationship it has with these factors. The purpose of this study was to fill this gap and investigate the relationship between motivation, diet adherence, anxiety symptoms, depression symptoms and physical functioning in people with celiac disease.

Questionnaires were administered to 433 people with celiac disease aged between 18 and 79 years (M = 32.73, DS = 11.54) to measure anxiety symptoms (State-Trait Anxiety Inventory-Y2), depression symptoms (Beck Depression Inventory), physical functioning (Scale of Physical Functioning), adherence to diet (Celiac Dietary Adherence Test) and motivation (Treatment Self-Regulation Questionnaire).

We used Structural Equation Modelling to examine the relationships of variables. Results revealed a direct relationship between motivation and diet adherence, anxiety symptoms, depression symptoms and physical functioning. They also illustrated the role played by diet adherence in mediating the relationship between motivation and anxiety symptoms, depression symptoms and physical functioning.

The results highlight the vital role played by motivation in people; indeed, analysis showed that motivation correlated to adherence to diet. It is therefore necessary to take this factor into account in the treatment of individuals with celiac disease.