Abstract Accumulating data suggest that behavioral activation interventions may be an effective approach to treating clinical depression. Given the high comorbidity and construct overlap between anxiety and mood disorders, a conceptually and methodologically integrated intervention that addresses symptoms of both conditions is indicated. As a means to this end, two questions are addressed. First, is the construct overlap and functional similarities of anxiety and mood disorders substantial enough to warrant an integrated intervention? Second, are behavioral activation treatments conceptually compatible with traditional behavioral interventions for anxiety disorders? To address these questions, behavioral activation interventions and their underlying principles briefly are described, followed by a functional analytic framework in which depressive and anxiety based symptom patterns are viewed as conceptually parallel in the context of a general negative affective syndrome. Finally, practical applications of behavioral activation for anxiety are discussed, and a case illustration is presented to highlight how behavioral activation may be used to treat a patient with coexistent anxiety and depressive pathology. Key Words: Behavioral Activation, Anxiety, Depression, Emotional Disorders. ********** Behavioral activation may be defined as a therapeutic process that emphasizes structured attempts at engendering increases in overt behaviors that are likely to bring patients into contact with reinforcing environmental contingencies and produce corresponding improvements in thoughts, mood, and overall quality of life (Hopko, Lejuez, Ruggiero, & Eifert, 2003). Traditional behavior therapy for depressive disorders included an activation component whereby the objective was to increase access to pleasant events and positive reinforcers and simultaneously decrease the intensity and frequency of aversive events and consequences (Lewinsohn & Atwood, 1969; Lewinsohn & Graf, 1973; Zeiss, Lewinsohn, & Munoz, 1979). Empirical support for these interventions generally was favorable, with such approaches deemed as effective in attenuating depressive behaviors as cognitive and interpersonal skills training methods (Zeiss et al., 1979). Other researchers were less supportive of conventional behavior therapy, however, and it was demonstrated that mildly to moderately depressed college students did not become less depressed following participation in events and behaviors rated as highly pleasurable (Hammen & Glass, 1975). Given equivocal support for pure behavioral interventions, paradigmatic undercurrents associated with the cognitive revolution, and the contention that more multi-faceted interventions that included cognitive restructuring rendered superior outcomes to pure behavioral approaches (Blaney, 1981; McLean & Hakstian, 1979), these pioneering behavioral therapies for depression gradually were replaced by more integrative cognitive-behavioral therapies (Beck, Rush, Shaw, & Emery, 1979; Lewinsohn, Antonuccio, Breckenridge, & Teri, 1984; Lewinsohn, Munoz, Youngren, & Zeiss, 1986; Lewinsohn, Sullivan, & Grosscup, 1980; Rehm, 1977). Following the publication of a component analysis study indicating that comprehensive cognitive-behavioral therapy was no more effective than a behavioral intervention in treating depression, interest in pure behavioral approaches was revitalized (Gortner, Gollan, Dobson, & Jacobson, 1998; Jacobson et al., 1996). Subsequent to this study, substantial preliminary data have accumulated that support the utility of two new interventions: Behavioral Activation (BA; Addis & Martell, 2004; Martell, Addis, & Jacobson, 2001) and the Brief Behavioral Activation Treatment for Depression (BATD; Lejuez, Hopko, & Hopko, 2001, 2002). These approaches have been effectively used with depressed patients in a community mental health center (Lejuez, Hopko, LePage, Hopko, & McNeil, 2001), an inpatient psychiatric facility (Hopko, Lejuez, LePage, Hopko, & McNeil, 2003), as a supplemental intervention for patients with co-existent Axis I (Hopko, Hopko, & Lejuez, 2004; Jakupak et al. …