Rorschach personality characteristics in obesity, eating behaviour and treatment outcome

Abstract

Obesity is a growing public health problem influenced by several factors. Psychology is essential in the study of obesity. Reasons for behaviour are complex and can be partly inaccessible and difficult to reveal in self-reported information. A performance-based psychological technique such as the Rorschach method enables a study of underlying personality aspects affecting behaviours and can provide data complementary to self-reports. This can be of particular relevance in deriving more understanding for obesity behaviours. The aim of this thesis was to study Rorschach personality characteristics in relation to obesity, eating behaviour and treatment outcome.

Patients with more difficulties with emotions could be considered to constitute a subgroup that was characterized by eating disorders, periodic variations in food intake and reporting psychological reasons for having an obese body size. Another type of difficulties in obesity could be related to coping with everyday demands. This was more frequent on a lower socio-economic level, and was further confirmed by irregular or chaotic meal habits. Mental distress was not worse in higher degrees of obesity. Bodily concern was negatively related to body weights, which can give more information on those patients who have reached the most health hazardous, physically limiting weights. (Study I and II)

Eating behaviour measured by means of a computerized eating monitor was studied in relation to personality. Affective responsiveness to external stimuli that would also include food cues was related to appetite through a higher eating rate. This finding could give new information on the classic externality theory implying that obese are more responsive to food stimuli. Results further showed that psychological stress overload can prompt eating, resulting in a higher eating rate. Affective responsiveness was also related to greater effect of the satiety-enhancing drug sibutramine in experimental test meals, implying that patients with sensitivity to food cues benefited from the enhanced satiety. Results further revealed that psychological moderators related to wishes for being helped and adjustment to social expectations can affect results in experimental designs. (Study III and IV)

Personality predictors of more weight loss in obesity treatments could be identified. These were related to physical or dependency needs for food. Such reasons for eating could be specifically altered by treatment interventions targeting hunger or eating habits, such as a satiety-enhancing drug or behaviour modification treatment. Ego dysfunctions such as distortions in perception of reality predicted less weight loss. Such ego dysfunctions would constitute more profound difficulties in obesity behaviours. These patients could have difficulties managing the demands posed on the participants in a behaviour modification treatment. (Study V and VI)