The present disclosure relates to a series of substituted phenyl cycloalkyl pyrrolidine (piperidine) spirolactams and amides of formula (Ia) and formula (Ib). wherein R1, R2, R3, R4, X, m, l, n, p and s are as described herein. More specifically, the compounds of this invention are modulators of H3 receptors and are, therefore, useful as pharmaceutical agents, especially in the treatment and/or prevention of a variety of diseases modulated by H3 receptors including diseases associated with the central nervous system. Additionally, this disclosure relates to methods of preparation of substituted phenyl cycloalkyl pyrrolidine (piperidine) spirolactams and amides of formula (Ia) and (Ib), and intermediates therefor.