Two primary outcomes of efficacy and acceptability showed a possible advantage of benzodiazepines over placebo .
Low- quality evidence shows a possible superiority of benzodiazepine over placebo in the short-term treatment of panic disorders .
Due to these limitations , our results regarding the efficacy of benzodiazepines versus placebo provide only limited guidance for clinical practice .
BACKGROUND Panic disorder is characterised by recurrent unexpected panic attacks consisting of a wave of intense fear that reaches a peak within a few minutes .
Panic disorder is a common disorder , with an estimated lifetime prevalence of 1 % to 5 % in the general population and a 7 % to 10 % prevalence in primary care setting s. Its aetiology is not fully understood and is probably heterogeneous .
Panic disorder is treated with psychological and pharmacological interventions , often used in combination .
Although benzodiazepines are frequently used in the treatment of panic disorder , guidelines recommend antidepressants , mainly selective serotonin reuptake inhibitors ( SSRIs ) , as first-line treatment for panic disorder , particularly due to their lower incidence of dependence and withdrawal reaction when compared to benzodiazepines .
Despite these recommendations , benzodiazepines are widely used in the treatment of panic disorder , probably because of their rapid onset of action .
OBJECTIVES To assess the efficacy and acceptability of benzodiazepines versus placebo in the treatment of panic disorder with or without agoraphobia in adults .
Overview of the Cross-National Collaborative Panic Study.
The Cross-National Collaborative Panic Study is a two-phase multinational , multicenter controlled trial for the evaluation of drug treatment of  panic disorder and associated agoraphobia .  The First Phase compared alprazolam with placebo in a large sample of more than 600 subjects at eight centers -- five in the United States , two in Canada , and one in Australia . The Second Phase compared alprazolam , imipramine hydrochloride , placebo  in more than 1100 patients in 14 countries . The scientific background , aims and purpose s , governance , and policies regarding statistical analyses and scientific presentations and publications are review ed as background for the series of individual articles reporting detailed findings from the First Phase
Two primary outcomes of efficacy and acceptability showed a possible advantage of benzodiazepines over placebo .
Low- quality evidence shows a possible superiority of benzodiazepine over placebo in the short-term treatment of panic disorders .
Due to these limitations , our results regarding the efficacy of benzodiazepines versus placebo provide only limited guidance for clinical practice .
BACKGROUND Panic disorder is characterised by recurrent unexpected panic attacks consisting of a wave of intense fear that reaches a peak within a few minutes .
Panic disorder is a common disorder , with an estimated lifetime prevalence of 1 % to 5 % in the general population and a 7 % to 10 % prevalence in primary care setting s. Its aetiology is not fully understood and is probably heterogeneous .
Panic disorder is treated with psychological and pharmacological interventions , often used in combination .
Although benzodiazepines are frequently used in the treatment of panic disorder , guidelines recommend antidepressants , mainly selective serotonin reuptake inhibitors ( SSRIs ) , as first-line treatment for panic disorder , particularly due to their lower incidence of dependence and withdrawal reaction when compared to benzodiazepines .
Despite these recommendations , benzodiazepines are widely used in the treatment of panic disorder , probably because of their rapid onset of action .
OBJECTIVES To assess the efficacy and acceptability of benzodiazepines versus placebo in the treatment of panic disorder with or without agoraphobia in adults .