Pharmaceutical formulations for treating neurological diseases are described, wherein the formulations comprise a pharmaceutically active agent-transport moiety complex. The formulations are suitable for administration via an intranasal route. Neurological diseases and conditions are associated with reduced brain insulin signaling (i.e., CNS insulin insensitivity), reduced dopaminergic signaling, reduced serotonergic signaling, reduced cholinergic signaling, or reduced GABAergic signaling, and include Alzheimers disease, Parkinsons disease, epilepsy, neuropathic pain, fibromyalgia, post-herpetic neuralgia, insomnia, or anxiety. Neurological diseases also include cancers of the central nervous system (CNS).