The present invention relates to the use of cannabidiol (CBD) in the treatment of Angelman syndrome (AS). CBD has It been shown to be particularly effective in improving anxiety in rodent models of AS. The CBD is preferably substantially pure. It may take the form of a highly purified extract of Cannabis such that the CBD is present at greater than 98% of the total extract (w/w) and the other components of the extract are characterised. Alternatively, the CBD is synthetically produced. Alternatively, the CBD may be used as a botanical drug substance (BDS) from a Cannabis plant in which CBD is the predominant cannabinoid. The CBD may also be present in combination with other cannabinoids and non-cannabinoid components such as terpenes. In use the CBD may be used concomitantly with one or more other medicaments. Alternatively, the CBD may be formulated for administration separately, sequentially or simultaneously with one or more medicaments or the combination may be provided in a single dosage form. Where the CBD is formulated for administration separately, sequentially or simultaneously it may be provided as a kit or together with instructions to administer the one or more components in the manner indicated. It may also be used as the sole medication, i.e. as a monotherapy.La présente invention concerne l'utilisation de cannabidiol (CBD) dans le traitement du syndrome d'Angelman (SA). Il a été démontré que CBD est particulièrement efficace pour améliorer l'anxiété dans des modèles de rongeur de SA. Le CBD est, de préférence, sensiblement pur. Il peut prendre la forme d'un extrait hautement purifié de cannabis de sorte que le CBD soit présent à plus de 98 % de l'extrait total (m/m) et que les autres composants de l'extrait soient caractérisés. En variante, le CBD est produit par synthèse. En variante, le CBD peut être utilisé en tant que substance médicamenteuse botanique (BDS) à partir d'une plante de cannabis dans laquelle CBD est le cannabinoïde prédominant. Le CB
