“…In humans, chronic stress and anxiety or panic disorder are associated with hyperactivation of the HPA axis [146,167], In rats, adminis tration of CRH is associated with 'anxious' behavior opposite to that observed in rats treated with benzodiazepines [146], Withdrawal Difficulties (Rebound Insom nia and Anxiety). The role of the noradrener gic system in production of a full withdrawal syndrome after long-term use of benzodiaze pines has been well established in many stud ies [113,114,116,117,119,121,122,124], Also, drugs with a strong direct effect on LC-NE activity have a higher potential for toler ance and withdrawal effects [168]. For exam ple, antihypertensive medication with direct effects on the NE system such as clonidine or methyldopa, may, when abruptly withdrawn, cause rebound hypertension and adrenergic hyperactivity [169], Also, cb-adrenoreceptors and NE significantly modulate limbic sei zures.…”