The impact of childhood experiences on the development of psychopathology is well established in the literature. Few studies, however, have assessed parental bonding during childhood as a predictor of response to anxiety disorders treatment. The aim of the study was to examine whether emotional memories of childhood parenting could predict short-term and long-term outcome in three different interventions for patients with generalized anxiety disorder (GAD): mindfulness-based intervention (Body in Mind Training [BMT]), fluoxetine (FLX), and an active control group (quality of life [QoL]). A total of 124 participants from a randomized controlled trial for GAD treatment were evaluated pre- and post-treatment and after 18 months. Patients were assessed for the severity of GAD symptoms (GAD-7, PSWQ, and DERS), early memories of warmth and safeness (EMWSS), and recall of perceived threat and subordination/submission in childhood (ELES). Negative childhood memories predicted a greater reduction in anxiety symptoms on BMT treatment compared to FLX and QoL, whereas positive childhood memories predicted more symptomatic improvement in the QoL group. Our findings suggest that individuals with GAD who have early memories of subordination and threat appear to benefit more from interventions that focus on developing emotion-regulation strategies and enhancing self-compassion, such as mindfulness-based interventions.