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We present diagnostic criteria for mal de débarquement syndrome (MdDS) for inclusion into the International Classification of Vestibular Disorders. The criteria include the following: 1] Non-spinning vertigo characterized by an oscillatory sensation ('rocking,' 'bobbing,' or 'swaying,') present continuously or for most of the day; 2] Onset occurs within 48 hours after the end of exposure to passive motion, 3] Symptoms temporarily reduce with exposure to passive motion (e.g. driving), and 4] Symptoms persist for >48 hours. MdDS may be designated as "in evolution," if symptoms are ongoing but the observation period has been less than 1 month; "transient," if symptoms resolve at or before 1 month and the observation period extends at least to the resolution point; or "persistent" if symptoms last for more than 1 month. Individuals with MdDS may develop co-existing symptoms of spatial disorientation, visual motion intolerance, fatigue, and exacerbation of headaches or anxiety. Features that distinguish MdDS from vestibular migraine, motion sickness, and persistent postural perceptual dizziness (PPPD) are reviewed. Motion-moderated oscillatory vertigo can also occur without a motion trigger, typically following another vestibular disorder, a medical illness, heightened psychological stress, or metabolic disturbance. Terminology for this non-motion triggered presentation has been varied as it has features of both MdDS and PPPD. Further research is needed into its phenomenological and biological relationship to MdDS, PPPD, and other vestibular disorders.

Objectives: Anhedonia, or the inability or the loss of the capacity to experience pleasure, is a core feature of several psychiatric disorders. Different types of anhedonia have been described including social and physical anhedonia, appetitive or motivational anhedonia, consummatory and anticipatory anhedonia. Musical anhedonia is a rare condition where individuals derive no reward responses from musical experience. Methods: We searched the PubMed electronic database for all articles with the search term "musical anhedonia". Results: A final set of 12 articles (six original research articles and six clinical case reports) comprised the set we reviewed. Conclusions: Individuals with specific musical anhedonia show normal responses to other types of reward, suggesting a specific deficit in musical reward pathways. Those individuals are not necessarily affected by psychiatric conditions, have normal musical perception capacities, and normal recognition of emotions depicted in music. Individual differences in the tendency to derive pleasure from music are associated with structural connections from auditory association areas in the superior temporal gyrus to the anterior insula. White matter connectivity may reflect individual differences in the normal variations of reward experiences in music. The moderate amount of heterogeneity between the reviewed studies is a limitation to the generalizability of our conclusions. (PsycInfo Database Record (c) 2021 APA, all rights reserved)