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 ) .
A Randomized, Naturalistic, Parallel-Group Study for the Long-Term Treatment of Panic Disorder With Clonazepam or Paroxetine
Abstract This long-term extension of an 8-week r and omized , naturalistic study in patients with panic disorder with or without agoraphobia compared the efficacy and safety of clonazepam  ( n = 47 ) and paroxetine  ( n = 37 ) over a 3-year total treatment duration . Target doses for all patients were 2 mg/d clonazepam and 40 mg/d paroxetine ( both taken at bedtime ) . This study reports data from the long-term period ( 34 months ) , following the initial 8-week treatment phase . Thus , total treatment duration was 36 months . Patients with a good primary outcome during acute treatment continued monotherapy with clonazepam or paroxetine , but patients with partial primary treatment success were switched to the combination therapy . At initiation of the long-term study , the mean doses of clonazepam and paroxetine were 1.9 ( SD , 0.30 ) and 38.4 ( SD , 3.74 ) mg/d , respectively . These doses were maintained until month 36 ( clonazepam 1.9 [ SD , 0.29 ] mg/d and paroxetine 38.2 [ SD , 3.87 ] mg/d ) . Long-term treatment with clonazepam led to a small but significantly better Clinical Global Impression (CGI)–Improvement rating than treatment with paroxetine ( mean difference : CGI-Severity scale −3.48 vs −3.24 , respectively , P = 0.02 ; CGI-Improvement scale 1.06 vs 1.11 , respectively , P = 0.04 ) . Both treatments similarly reduced the number of panic attacks and severity of anxiety . Patients treated with clonazepam had significantly fewer adverse events than those treated with paroxetine ( 28.9 % vs 70.6 % , P < 0.001 ) . The efficacy of clonazepam and paroxetine for the treatment of panic disorder was maintained over the long-term course . There was a significant advantage with clonazepam over paroxetine with respect to the frequency and nature of adverse events
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 ) .