This research tested the idea that a cognitive vulnerability to depression can be concealed by thought suppression and revealed when cognitive demands undermine mental control. Depressive, at-risk, and nondepressive participants unscrambled sentences that could from either positive or depressive statements. Half of the participants also received a cognitive load. The results indicated that without a load, at-risk participants showed little evidence of depressive thinking, producing a similar rate of positive statements as did nondepressive individuals and a lower percentage of negative statements than did depressive participants. However, the cognitive load caused an increase in at-risk participants' production of negative statements, revealing a previously undetected tendency toward negative thinking that made them resemble depressive participants. As predicted, this effect was especially pronounced among individuals who routinely engaged in thought suppression.