Altered emotion-modulated startle in young adults with a family history of alcoholism

BACKGROUND: Alcoholism risk may be accompanied by poor regulation of emotions, signaling altered central nervous system processes. This study used the emotion-modulated startle paradigm to test the hypothesis that young adults with a positive paternal history of alcoholism (FH+), relative to family-history-negative persons (FH-), have altered emotional reactivity to environmental cues. METHODS: We tested 30 FH+ and 30 FH-, 15 males and 15 females in each group. Participants completed self-report instruments and interviews and had eye blink electromyograms (EMG) measured to acoustic startle probes while viewing color photographs rated as affectively pleasant, neutral, and unpleasant. RESULTS: FH- had the expected linear increase in startle magnitude, with eye blink EMG gaining in strength (F = 18, p < 0.0002) from pleasant to neutral to unpleasant slides. In contrast, FH+ did not show EMG potentiation to the unpleasant slides and therefore lacked the same linear trend (F < 1, p > 0.4). Notably, FH groups rated the emotional valence and arousal of the photographs in similar ways. Self-reported negative affect partly accounted for the lack of startle potentiation in FH+, suggesting that startle modulation differences between the groups may be associated with underlying psychological characteristics. CONCLUSIONS: These findings implicate altered limbic outputs to the startle pathway in FH+ despite normal conscious evaluation of emotional arousal and pleasantness of the slides. This method may provide a useful paradigm for testing processing of emotionally relevant stimuli in relation to risk for alcohol use disorders.