A method for reducing permeability of a physiological barrier comprising adherens junctions and/or tight junctions in a first subject suffering from a central nervous system (CNS) disorder or other disorder, wherein said CNS or other disorder is characterized by increased permeability of a physiological barrier relative to the permeability of said barrier in a second subject not suffering from said CNS or other disorder, wherein said CNS or other disorder is characterized by increased permeability of said physiological barrier due to enhanced tyrosine phosphorylation, said method comprising administering to said first subject an effective amount of an agent which promotes tyrosine protein dephosphorylation of at least one component of a cadherin/catenin complex in said adherens junctions and/or tight junctions.