The study will evaluate the long-term maintenance of efficacy of Lu AA21004 in patients with Generalized Anxiety Disorder (GAD) who responded to acute treatment with Lu AA21004.

GAD is a common and disabling mental disorder associated with substantial medical and psychiatric comorbidity and occupational impairment. It is characterized by inappropriate or excessive anxiety and worrying that persists over time for more than six months. Common features include apprehension, with worries about future misfortune; inner tension and difficulty in concentrating; motor tension, with restlessness, tremor and headache; and autonomic anxiety symptoms, with excessive perspiration, dry mouth and epigastric discomfort. GAD is typically a chronic disorder with a high relapse rate and therefore requires effective long-term treatment. Long-term studies are necessary to demonstrate that the short-term effect is maintained.

Inclusion Criteria:

The patient has GAD as the primary diagnosis according to DSM-IV-TR criteria (classification code 300.02).

• The patient has a HAM-A total score >=20 at screening and baseline visits
• The patient has a HAM-A score >=2 on both Item 1 (anxious mood) and Item 2 (tension) at screening and baseline visits
• The patient has a MADRS total score <=16 at screening and baseline visits

Exclusion Criteria:

• Any current psychiatric disorder other than GAD as defined in the DSM-IV-TR (assessed with the MINI)
• Any substance disorder (except nicotine and caffeine) within the previous 6 months as defined in the DSM-IV-TR
• Women of childbearing potential not using effective contraception

Other protocol-defined inclusion and exclusion criteria may apply.