 Several other European studies independently confirmed the occurrence of RBD in the general population and clinical samples.RBD was thus included in the 10th classification of mental and behavioural disorders (ICD-10 F38.1) published by the World Health Organization in 1992 (WHO, 1992; WHO, 1993).Less frequent episodes of brief depressions were labelled infrequent brief depression and not included in ICD-10.