Mirtazapine, sold under the brand name Remeron among others, is an antidepressant of the atypical antidepressants class primarily used to treat depression.[1][9] Its full effect may take more than four weeks to occur, with some benefit possibly as early as one to two weeks.[9][3] Often it is used in depression complicated by anxiety or trouble sleeping.[8][11] It is taken by mouth.[9]