Previous studies have established a link between the lack of affective modulation of startle response and either clinical or nonclinical depression. Although we found no evidence that never-quitters had been diagnosed with major depressive disorder more often than had abstainers, relapsers, and control participants, never-quitters reported a significant increase in self-reported negative affect and a significant decrease in self-reported positive affect, as measured by the PANAS negative and positive affect subscales respectively, across the postcessation sessions. Both PANAS negative and positive affect subscales have been shown to be significantly correlated with the BDI, and they measures two dimensions of mood that are consistent with subjective depressive experiences of distress and anhedonia (Watson et al., 1988). Thus, while it is unlikely that a diagnosis of depression would account for the undifferentiated startle response in never-quitters, the post-cessation increase in negative affect and decrease in positive affect reported by never-quitters may explain the decomposition of their affect-modulated startle response.
