The authors present the case of an adult woman who was treated in the mental health system for many years for a syndrome of mixed anxiety and depression unresponsive to psychopharmacologic or psychotherapeutic treatment. A computed tomography scan revealed asymmetrical enlargement of the right temporal horn. This finding, as well as findings of severe difficulties in spatial relations together with mildly abnormal posturing of the left hand when walking (especially when the gait was stressed), suggested that the patient had a developmental disability of the right cerebral hemisphere. The authors conclude that because such patients might appear to have primarily psychiatric rather than neurologic problems, the diagnosis of right hemisphere dysfunction should be considered when the clinical presentation is indicative of atypical anxiety and affective disorders.