Background: Increasing evidence shows that PTSD and AD are both associated with abnormalities in stress reactivity. In PTSD, the increase in hormonal response and subjective increases in affective symptoms provide evidence for abnormalities in stress reactivity. In AD, significant increases in craving after stressful stimuli and alcohol cues point to abnormalities in stress response. There is increasing evidence that these laboratory paradigms are clinically relevant and may be useful in predicting treatment outcomes in patients with substance use disorders. Stress induced craving has been used as a marker for relapse. Individuals with greater stress reactivity have a shorter time to relapse to their preferred substance than individuals with lesser stress reactivity.