Anxiety Sensitivity (AS) is the fear of normal, arousal-related bodily sensations due to the belief that they have negative consequences. AS is a transdiagnostic construct, and high AS is associated with psychopathology, including panic disorder, social anxiety disorder, generalized anxiety disorder, depression, and alcohol-use disorders. There is research and clinical interest in developing brief and transdiagnostic interventions to streamline treatment. Targeting AS through brief interventions may be one way to accomplish this goal. Therefore, the purpose of this dissertation was to advance the literature on AS by examining the efficacy and transdiagnosticity of two brief interventions for AS. Cognitive mediators of change in AS were also examined. Target variables were psychopathology symptoms and cognitive processes, including interpretation biases, attentional biases, and perceived control. Study 1 investigated the immediate and short-term efficacy of a brief intervention that included a single session of psychoeducation and daily interoceptive exposure practices. Participants with high AS were randomly assigned to the intervention (n = 19) or health education control condition (n = 16). Participants in the intervention condition appeared to demonstrate reductions in AS, one facet of interpretation bias, social anxiety symptoms, and motivation to consume alcohol. Methodological issues, however, limited conclusions about the efficacy of the intervention. Finally, the three potential cognitive mediators did not mediate change in AS. Study 2 investigated the efficacy of a computerized cognitive bias modification (CBM) program. Participants with high AS were randomly assigned to 4 sessions of CBM (n= 24) or 4 sessions of sham training (n= 24). Sessions occurred over a 2-week period. At the end of the intervention period, the CBM condition appeared to show reductions in AS, interpretive biases, and almost all facets of psychopathology. However, similar changes were found in the control condition. Again, the three potential cognitive mediators did not mediate change in AS. Taken together, these findings provide limited support for the efficacy of psychoeducation and CBM as brief, transdiagnostic interventions. However, both studies must be interpreted in light of major limitations, which include limited homework completion in Study 1 and a control training task that induced training effects in Study 2.