The primary objective of this study is to evaluate the efficacy of quetiapine SR compared to placebo in increasing time from randomisation to an anxiety event in patients with generalised anxiety disorder (GAD).

PLEASE NOTE: Seroquel SR and Seroquel XR refer to the same formulation. The SR designation was changed to XR after consultation with FDA.

Inclusion Criteria:

• Patients will be male or female, 18 to 65 years of age (inclusive), with a diagnosis of GAD according to DSM-IV criteria 300.02 as assessed by the MINI.

Exclusion Criteria:

• Patients suffering from depressive symptoms, defined as having a Montgomery-Åsberg Depression Rating Scale (MADRS) total score of 17 or more at the enrolment visit, will be excluded from participation in this study.