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 ) .
Agomelatine prevents relapse in generalized anxiety disorder: a 6-month randomized, double-blind, placebo-controlled discontinuation study.
OBJECTIVE This study evaluated the efficacy and tolerability of agomelatine in the prevention of relapse in patients with generalized anxiety disorder ( GAD ) . METHOD Patients with GAD ( Hamilton Anxiety Rating Scale [ HARS ] ≥ 22 , with items 1 and 2 ≥ 2 , item 1 + 2 ≥ 5 ; Montgomery-Asberg Depression Rating Scale [ MADRS ] ≤ 16 ; and < 20 % decrease in HARS total score between screening and baseline ) who responded to a 16-week course of agomelatine 25 - 50 mg/d treatment were r and omly assigned to receive continuation treatment with agomelatine ( n = 113 ) or placebo ( n = 114 ) for 26 weeks . The main outcome measure was time to relapse during this maintenance period . The estimated risk of relapse was calculated using the Kaplan-Meier method , and groups were compared using a log-rank test stratified for country . The study was undertaken in 31 clinical centers in Canada , Denmark , Estonia , Finl and , Hungary , and Sweden from November 2007 to September 2009 . RESULTS During the 6-month maintenance period , the proportion of patients that relapsed during the double-blind period in the agomelatine group ( 22 patients , 19.5 % ) was lower than in the placebo group ( 35 patients , 30.7 % ) . The risk of relapse over time was significantly lower for patients who continued treatment than for those switched to placebo ( P = .046 , log-rank test stratified for country ) . Agomelatine was also superior to placebo in preventing relapse in the subset of more severe patients with baseline HARS total score ≥ 25 and CGI-S score ≥ 5 . The tolerability  of agomelatine was good throughout the study , and there were no differences in discontinuation symptoms after withdrawal of agomelatine in comparison to maintenance on agomelatine . CONCLUSIONS The present study extends the positive findings of an earlier short-term study of agomelatine in GAD , demonstrating that agomelatine is effective and well-tolerated in the longer-term treatment of this chronic disorder . TRIAL REGISTRATION www.is rct n.org identifier : IS RCT N38094599
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 ) .