Premenstrual Dysphoric Disorder (PMDD) can be differentiated from Premenstrual Syndrome (PMS) by the use of the research criteria provided by the Diagnostic and Statistical Manual (DSM) IV. Indeed, PMS corresponds to mild clinical symptoms, such as breast tenderness, bloating, headache and concomitant minor mood changes, while premenstrual magnification occurs when physical and psychological symptoms of a concurrent axis I disorder get worse during the late luteal phase. Changes in appetite and eating behavior have been documented in women suffering from PMS, with an increased food intake occurring during the luteal phase. Moreover, in women with PMS, a major effect of the phase of the menstrual cycle on appetite has been documented and a high correlation with self-ratings of mood, particularly depression, has been described only in such disturbance. The aim of the present study was to analyse the clinical similarities between PMDD and Eating Disorders (in particular Bulimia Nervosa and Binge Eating Disorder). Thus, we compared the DSM III-R comorbidity, the personality dimensions and the eating attitudes in these patients, attempting to identify any relationship between groups. Twelve PMDD women (mean age 28 years), diagnosed using DSM IV criteria and premenstrual assessor form, were compared with 10 eating disorder (ED) women (6 Bulimia Nervosa, 4 Binge Eating Disorder) (mean age 25 years) and with 10 control women matched for age. The following instruments were used: (i) clinical interview with DSM III-R criteria (SCID); (ii) a psychometric study with TPQ for the evaluation of three personality dimensions (novelty seeking, harm avoidance and reward dependence); (iii) EAT/26 for the evaluation of eating attitudes. Results show that a high comorbidity for mood and anxiety disorders in PMDD and ED is well documented. Our PMDD patients share a 16.6% of comorbidity with ED, whereas such an association is present only in 2.3% of the general population. In addition, as a common clue, the personality dimension, harm avoidance, linked to a serotonin mediation is significantly more frequent in PMDD and ED than in normal controls.
In conclusion: from the present study it seems clear that a certain degree of similarity exists between the PMDD and ED. However, whether or not these two disorders really share common ground from a physiopathological point of view still has to be clarified by more extensive studies.