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Background Attention Bias Modification Treatment (ABMT) is a newly-emerging promising treatment for anxiety disorders. While recent randomized control trials (RCTs) suggest that ABMT reduces anxiety, therapeutic effects have not been summarized quantitatively. Methods Standard meta-analytic procedures were used to summarize the effect of ABMT on anxiety. Using MEDLINE, January 1995 to February 2010, we identified RCTs comparing the effects on anxiety of ABMT and quantified effect sizes using Hedge’s d. Results Twelve studies met inclusion criteria, including 467 participants from 10 publications. ABMT produced significantly greater reductions in anxiety than control training, with a medium effect (d = 0.61, p <.001). Age and gender did not moderate the effect of ABMT on anxiety, while several characteristics of the ABMT training did. Conclusions ABMT shows promise as a novel treatment for anxiety. Additional RCTs are needed to fully evaluate the degree to which these findings replicate and apply to patients. Future work should consider the precise role for ABMT in the broader anxiety-disorder therapeutic armamentarium.

The aim of the current study was twofold: (1) to systematically examine differences in fear conditioning between anxiety patients and healthy controls using meta-analytic methods, and (2) to examine the extent to which study characteristics may account for the variability in findings across studies. Forty-four studies (published between 1920 and 2013) with data on 963 anxiety disordered patients and 1,222 control subjects were obtained through PubMed and PsycINFO, as well as from a previous meta-analysis on fear conditioning (Lissek et al.). Results demonstrated robustly increased fear responses to conditioned safety cues (CS-) in anxiety patients compared to controls during acquisition. This effect may represent an impaired ability to inhibit fear in the presence of safety cues (CS-) and/or may signify an increased tendency in anxiety disordered patients to generalize fear responses to safe stimuli resembling the conditioned danger cue (CS+). In contrast, during extinction, patients show stronger fear responses to the CS+ and a trend toward increased discrimination learning (differentiation between the CS+ and CS-) compared to controls, indicating delayed and/or reduced extinction of fear in anxiety patients. Finally, none of the included study characteristics, such as the type of fear measure (subjective vs. psychophysiological index of fear), could account significantly for the variance in effect sizes across studies. Further research is needed to investigate the predictive value of fear extinction on treatment outcome, as extinction processes are thought to underlie the beneficial effects of exposure treatment in anxiety disorders.

Objective-Classical conditioning features prominently in many etiological accounts of panic disorder. According to such accounts, neutral conditioned stimuli present during panic attacks acquire panicogenic properties. Conditioned stimuli triggering panic symptoms are not limited to the original conditioned stimuli but are thought to generalize to stimuli resembling those co-occurring with panic, resulting in the proliferation of panic cues. The authors conducted a laboratory-based assessment of this potential correlate of panic disorder by testing the degree to which panic patients and healthy subjects manifest generalization of conditioned fear.Method-Nineteen patients with a DSM-IV-TR diagnosis of panic disorder and 19 healthy comparison subjects were recruited for the study. The fear-generalization paradigm consisted of 10 rings of graded size presented on a computer monitor; one extreme size was a conditioned danger cue, the other extreme a conditioned safety cue, and the eight rings of intermediary size created a continuum of similarity from one extreme to the other. Generalization was assessed by conditioned fear potentiating of the startle blink reflex as measured with electromyography (EMG).Results-Panic patients displayed stronger conditioned generalization than comparison subjects, as reflected by startle EMG. Conditioned fear in panic patients generalized to rings with up to three units of dissimilarity to the conditioned danger cue, whereas generalization in comparison subjects was restricted to rings with only one unit of dissimilarity.Conclusions-The findings demonstrate a marked proclivity toward fear overgeneralization in panic disorder and provide a methodology for laboratory-based investigations of this central, yet understudied, conditioning correlate of panic. Given the putative molecular basis of fear conditioning, these results may have implications for novel treatments and prevention in panic disorder.Many etiological accounts of panic disorder implicate classical conditioning as a central pathogen (1-4). According to these accounts, neutral conditioned stimuli that are present during an aversive panic attack acquire the capacity to trigger anticipatory anxiety for, or an actual occurrence of, panic attacks through classical conditioning (1,2,5). Conditioned stimuli contributing to the onset and maintenance of panic disorder are thought to extend to exteroceptive and interoceptive stimulus events resembling those co-occurring with panic (1, 2,6) via stimulus generalization-a learning mechanism whereby fear responses extend to a range of stimuli resembling the original conditioned stimuli (7). For example, conditioned fear to the environment where a panic attack occurs (e.g., a specific shopping mall) might transfer, Address correspondence and reprint requests to Dr. Lissek, NIMH, 15K North Dr., Rm. 200, Bethesda, MD 20892-2670; lisseks@mail.nih.gov. Presented in part at the 161st annual meeting of the American Psychiatric Association, Washington, D.C., May 3-8, 2008; and the 47...

Though generalization of conditioned fear has been implicated as a central feature of pathological anxiety, surprisingly little is known about the psychobiology of this learning phenomenon in humans. Whereas animal work has frequently applied methods to examine generalization gradients to study the gradual weakening of the conditioned-fear response as the test stimulus increasingly differs from the conditioned stimulus (CS), to our knowledge no psychobiological studies of such gradients have been conducted in humans over the last 40 years. The current effort validates an updated generalization paradigm incorporating more recent methods for the objective measurement of anxiety (fear-potentiated startle). The paradigm employs 10, quasi-randomly presented, rings of graduallyincreasing size with extremes serving as CS+ and CS-. The eight rings of intermediary size serve as generalization stimuli (GS's) and create a continuum-of-similarity from CS+ to CS-. Both startle data and online self-report ratings demonstrate continuous decreases in generalization as the presented stimulus becomes less similar to the CS+. The current paradigm represents an updated and efficacious tool with which to study fear generalization-a central, yet understudied conditioningcorrelate of pathologic anxiety.