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 ) .
Long-term efficacy of pregabalin in generalized anxiety disorder
A multicenter , r and omized , placebo-controlled , double-blind study was conducted to evaluate the efficacy of pregabalin in preventing relapse of generalized anxiety disorder ( GAD )  after response to short-term treatment . Out patients ( n=624 ) with GAD for ≥1 year received open-label pregabalin ( 450 mg/day ) for 8 weeks and , if a clinical response was observed , were r and omized to receive either pregabalin ( 450 mg/day ; n=168 ) or placebo ( n=170 ) for 24 weeks . The primary efficacy parameter was time to relapse . Among responders to open-label acute treatment with pregabalin  , time to relapse of GAD was significantly longer for patients treated with pregabalin compared with placebo ( P<0.0001 ) . Fifty per cent of the placebo group had relapsed by day 23 , and at study endpoint , 65 % had relapsed . In the pregabalin group , only 42 % had relapsed by study end . Total attrition during double-blind treatment was somewhat higher on pregabalin compared with placebo ( 21.4 vs. 15.3 % ) ; attrition owing to adverse events ( AEs ) was also somewhat higher on pregabalin ( 6.0 vs. 2.4 % ) . AEs were relatively low in the double-blind phase ; only three AEs occurred with an incidence of more than 5 % on pregabalin and placebo , respectively : infection ( 14.9 vs. 11.2 % ) , headache ( 10.1 vs. 11.2 % ) , and somnolence ( 6.0 vs. 0 % ) . No safety concerns were identified with long-term treatment . The study indicates that pregabalin is an effective treatment for the prevention of relapse in patients with GAD
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 ) .