WINSTON-SALEM, N.C.--(BUSINESS WIRE)--Targacept, Inc. (NASDAQ: TRGT), a clinical-stage biopharmaceutical company developing novel NNR Therapeutics™, today announced the initiation of two clinical studies of TC-5619, a Phase 2b study evaluating the product candidate as a treatment for negative symptoms and cognitive dysfunction in schizophrenia and a Phase 2 study evaluating the product candidate in adults as a treatment for attention deficit/hyperactivity disorder (ADHD), inattentive-predominant. TC-5619 is a highly selective modulator of the alpha7 neuronal nicotinic receptor.