Provided are methods for treating and/or reducing the symptoms of a neurological or neurodevelopmental disease or disorder characterized by ectopic expression of certain ion channels, in particular, the Nav1.8 subtype SCN10a sodium channel, or the KCNQ1 potassium channel, in neuronal cells of the central nervous system (CNS) of a subject by administering to a subject in need an antagonist of one or both of these ion channels, and in particular, an antagonist of SCN10a, to block, reduce, or suppress the aberrant CNS neuronal ion channel expression and/or activity and normalize behavioral and cognitive defects associated with the neurological and neurodevelopmental disease or disorder, so as to treat and/or reduce the symptoms of the neurological or neurodevelopmental disease or disorder. Examples of such diseases or disorders that may be treated by the described methods include, for example, Pitt-Hopkins Syndrome (PTHS), autism, autism spectrum disorder, schizophrenia, 18q syndrome and the like.