Our review confirms the usefulness of long-term pharmacological treatments for PD and GAD and suggests that they can provide further improvement over that obtained during short-term therapy .
Paroxetine , escitalopram , and clonazepam can be effective for long-term treatment of PD .
Pregabalin and quetiapine can be effective for long-term treatment of GAD , while preliminary suggestions emerged for agomelatine and vortioxetine .
We did not find any evidence for determining the optimal length and /or dosage of medications to minimize the relapse risk .
Many aspects of long-term pharmacological treatments for  anxiety disorders ( AnxDs ) are still debated .
We undertook an up date d systematic review of long-term pharmacological studies on panic disorder ( PD ) , generalized anxiety disorder ( GAD ) , and social anxiety disorder ( SAD ) .
Pregabalin long-term treatment and assessment of discontinuation in patients with generalized anxiety disorder.
Discontinuation effects following cessation of 12 and 24 wk of pregabalin treatment for  generalized anxiety disorder ( GAD )  were evaluated in a placebo- and lorazepam-controlled , r and omized , double-blind , multicentre trial conducted in 16 countries . The study design consisted of two 12-wk treatment periods ( periods 1 and 2 ) , each followed by a 1-wk taper and two post-discontinuation assessment s , one immediately following the taper and one 1-wk post-taper . Patients were assigned to receive an initially flexible dose of pregabalin 450 - 600 mg/d , pregabalin 150 - 300 mg/d , or lorazepam 3 - 4 mg/d for 6 wk ; responders continued fixed-dose therapy for 6 additional weeks . Patients entering period 2 continued on the same fixed dose or switched to placebo .  Discontinuation effects were evaluated with the Physician Withdrawal Checklist ( PWC ) and reported discontinuation-emergent signs and symptoms . Rebound anxiety was measured with the Hamilton Anxiety Rating Scale . GAD symptoms improved with all treatments and improvements were maintained over 12 and 24 wk . Low levels of discontinuation symptoms were evident in all treatment groups . For patients who received active treatment during both periods , mean ( 95 % confidence interval ) increases on the PWC from last visit on active treatment to the second post-discontinuation assessment were : pregabalin 450 - 600 mg/d : 2.8 ( 1.6 - 3.9 ) , pregabalin 150 - 300 mg/d : 1.7 ( 0.7 - 2.8 ) , lorazepam 3 - 4 mg/d : 2.2 ( 1.0 - 3.5 ) . Rates of rebound anxiety were also low at both 12 and 24 wk ( 0 - 6 % ) . This suggests that risk of discontinuation symptoms and rebound anxiety are low for pregabalin after 12 and 24 wk of treatment
Our review confirms the usefulness of long-term pharmacological treatments for PD and GAD and suggests that they can provide further improvement over that obtained during short-term therapy .
Paroxetine , escitalopram , and clonazepam can be effective for long-term treatment of PD .
Pregabalin and quetiapine can be effective for long-term treatment of GAD , while preliminary suggestions emerged for agomelatine and vortioxetine .
We did not find any evidence for determining the optimal length and /or dosage of medications to minimize the relapse risk .
Many aspects of long-term pharmacological treatments for  anxiety disorders ( AnxDs ) are still debated .
We undertook an up date d systematic review of long-term pharmacological studies on panic disorder ( PD ) , generalized anxiety disorder ( GAD ) , and social anxiety disorder ( SAD ) .