flexible with flexural stiffness of not more than 2 cn u00d7 cm 2 examples of additives which are used with the acrylate copolymers containing carboxy groups are alkali metal hydroxides preferably potassium hydroxide and basic polymers preferably the abovementioned butyl methacrylate 2 dimethylaminoethyl methacrylate methyl methacrylate copolymer in one particularly advantageous embodiment the acrylate copolymer containing carboxyl groups has been crosslinked by aluminum ions or titanium ions it is advantageous for their also to be at least one strongly water binding auxiliary present in the ttss of the invention preferably a polymer containing carboxy groups or its pharmaceutically acceptable salt this is preferably an auxiliary from the group consisting of the sodium or calcium salts of crosslinked carboxymethylcellulose or of crosslinked polyacrylic acid and it is advantageous for this auxiliary to be present in powder form dispersed in one or more of the matrix layers the content of the water binding constituent in the matrix is generally from 1 to 10 w w preferably from 2 to 4 w w the other active ingredients and or auxiliaries which act on the central nervous system and may be used are those previously described in the prior art in connection with nicotine for transdermal therapeutic systems.