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 ) .
Extended release quetiapine fumarate (quetiapine XR) monotherapy as maintenance treatment for generalized anxiety disorder: a long-term, randomized, placebo-controlled trial
The objective of this study was to evaluate the efficacy and tolerability of extended release quetiapine fumarate ( quetiapine XR ) as maintenance monotherapy for patients with generalized anxiety disorder ( GAD ) .  Time-to-event ( anxiety symptom recurrence ; maximum 52 weeks ) multicenter , r and omized-withdrawal , parallel-group , double-blind , placebo-controlled study of quetiapine XR ( 50–300 mg/day ) following open-label run-in ( 4–8 weeks ) and open-label stabilization ( ≥12 weeks ) . Primary variable : time from r and omization to anxiety event . Secondary variables included : Hamilton Anxiety Rating Scale ( HAM-A ) total , HAM-A psychic/somatic anxiety factors , Clinical Global Impression-Severity of Illness ( CGI-S ) , and Quality of Life , Enjoyment and Satisfaction Question naire ( Q-LES-Q ) scores ; adverse events ( AE ) reporting . Four hundred and thirty-two patients , stabilized on quetiapine XR , were r and omized to continue quetiapine XR ( N=216 ) or switch to placebo ( N=216 ) . Risk of anxiety symptom recurrence was significantly reduced by 81 % for quetiapine XR versus placebo : hazard ratio=0.19 ( 95 % confidence interval 0.12–0.31 ; P<0.001 ) . Fewer patients receiving quetiapine XR ( N=22 , 10.2 % ) than placebo ( N=84 , 38.9 % ) experienced anxiety symptom recurrence . Significant differences were observed between quetiapine XR and placebo in : HAM-A total , psychic/somatic , CGI-S ( all P<0.001 ) and Q-LES-Q ( P<0.05 ) scores . AEs ( > 10 % ) during open-label treatment were dry mouth , sedation , somnolence , dizziness , fatigue , and constipation . During r and omized treatment , the most common AEs for quetiapine XR were headache and nasopharyngitis  . Quetiapine XR monotherapy reduced the risk of anxiety symptom recurrence in patients with GAD stabilized on quetiapine XR , with tolerability results consistent with the known profile of quetiapine
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 ) .