And the winner is number 1. It takes longer than a week for a dose increase to have an effect. The improvement you noticed was almost certainly either happenstance or placebo. ADs have no direct effect on anxiety in the way say benzodiazepines do. They work by triggering brain changes and it is these physical changes which create the therapeutic response. This take more than a week. Give it at least 5-6 weeks. It could take even longer.