Children referred for growth hormone (GH) treatment have increased school achievement problems, lack appropriate social skills and show several forms of behavior problems. A multicenter study in the United States has revealed that many GH-impaired children exhibit a cluster of behavioral symptoms involving disorders of mood and attention. Anxiety, depression, somatic complaints and attention deficits have been identified. These symptoms decline in frequency over a period of 3 years, beginning shortly after GH replacement therapy is started. Many of the patients who have received GH and had good growth responses show lower than average quality of life in young adulthood after treatment is completed. GH-deficient adults placed on GH therapy report improvement in psychological well-being and health status, suggesting that GH might have a central neuroendocrine action. Among a group of adults who were GH deficient as children, we find a high incidence of social phobia, a psychiatric disorder linked to GH secretion and usually accompanied by poor life quality. An ongoing study of non-GH-deficient short individuals suggests that short stature is not the cause of this outcome. We conclude that the origins of psychiatric comorbidities, such as social phobia and depression, in GH deficient adults are likely to be neuroendocrine as well as psychosocial.