Inclusion Criteria:  Male or female of at least 18 years at screening Diagnosis of chronic (at least 6 wks.) idiopathic pruritus Pruritus Numeric Rating Scale > = 4  Exclusion Criteria:  Pruritus caused by a dermatological or a systemic conditions Suicidal crisis, moderate, or severe Psychosis (schizophrenia, persistent delusional disorder) Bipolar disorder, not stabilized or decompensating Personality disorder, decompensated