[Emotional reactivity in euthymic bipolar patients].

BACKGROUND

Euthymic states in bipolar disorders are usually considered to be lacking serious psychiatric disorders. Moreover, recent results prove the need to take an interest in a potential emotional dysregulation during these intercrisis periods. Therefore, it seems relevant not only to focus on the emotions tonality (sadness/euphoria) felt by patients, but also on the intensity of their emotional background. Several reasons argue for a disturbance of emotional reactivity in euthymic bipolar patients. First, most bipolar patients spontaneously claim they have a higher sensitivity than average, which may lead to extreme emotional reactions, even during intercrisis periods. Secondly, the emotional reactivity is a way to raise the question of the bipolar patients' vulnerability to stress in euthymic periods. Several studies have shown the impact of stressful life events on the rate of relapse into bipolar disorders. The aim of this study is to examine the emotional reactivity of euthymic bipolar patients in comparison with a control group, using a test of emotional induction. Our hypothesis is that euthymic bipolar patients have a higher emotional reactivity than controls.

METHOD

One hundred and forty-five subjects were recruited: 90 controls and 55 euthymic bipolar patients. The patients were interviewed by a trained psychologist using the French version of the DIGS providing DSM-IV diagnosis. The euthymic state was confirmed with both MADRS (score<12) and Bech's Manic Scale (score<4). The subjective emotional reactivity of the subjects was assessed using a method of emotional induction, based on viewing a set of 18 (positive, negative or neutral) pictures. The subjects have to appreciate the valence (pleasant, neutral or unpleasant thoughts) and assess the arousal (degree of emotion triggered by each picture).

RESULTS

On average, euthymic bipolar patients report the same valence and arousal to positive (F [1.143]=0.18, p=0.68) and negative (F [1.143]=0.52, p=0.47) pictures as control subjects. Neutral pictures, however, were considered more pleasant and moving by euthymic bipolar patients than by control subjects (F [1.143]=8.40, p=0.004).

CONCLUSION

Euthymic bipolar patients seem to present an emotional hyperactivity which occurs especially in neutral situations. These results partly corroborate outcomes of other authors, while providing a new methodology through the emotional induction test. The highlight of emotional hyperreactivity during intercrisis periods allows us to understand differently the topic of specific vulnerability to stress of bipolar patients. This hypersensitivity could lead to thymic decompensations and could be linked with an emotional dysregulation, potential endophenotype of the bipolar pathology. Beyond the interest in understanding the physiopathology of the bipolar disorder, it could be associated with several clinical applications as well as in the psychoeducational field and in the screening of the individual risk within the family of bipolar subjects.