The objective is to evaluate the efficacy and safety of two doses of SSR149415 (250 mg and 100 mg twice daily) compared to placebo and paroxetine 20 mg once daily in outpatients with generalized anxiety disorder

Inclusion Criteria:

• Diagnosis of generalized anxiety disorder, as defined by Diagnostic and Statistical Manual of Mental Disorders, 4th Edition (DSM-IV) criteria and confirmed by the semi-structured Mini International Neuropsychiatric Interview (MINI) General Anxiety Disorder (GAD) Plus Module.

Exclusion Criteria:

• Total score of less than 22 on the (Hamilton Anxiety rating scale)HAM-A.
• Montgomery-Asberg Depression Rating Scale (MADRS) total score greater than 17.
• Patients with a current history (within 6 months) of major depressive disorder or history or presence of bipolar disorders or psychotic disorders.
• Patients with alcohol dependence or abuse or substance dependence or abuse in the past 12 months except nicotine or caffeine dependence.
• Patients who have used the following prior to entry into Acute Phase: antipsychotics within 3 months, antidepressants including Monoamine oxidase inhibitors (MAOIs) within 1 month, anxiolytics within 2 weeks, mood-stabilizer (lithium, anticonvulsants) within 1 month, and/or high dose or prolonged benzodiazepine (continuous use for 3 months prior to admission) use.

The investigator will evaluate whether there are other reasons why a patient may not participate.