Prolonged latency in the appearance of REM sleep as a marker of depression has been demonstrated in patients with the sickle-cell disease. To detect the possible existence of depressive disturbances in patients with sickle-cell disease, the Hamilton rating scale for depression (17 items) was used in 30 patients with homozygote sickle-cell disease and 31 carriers of the sickle-cell trait, treated or not with vasodilator drugs. None of the 61 subjects studied presented a score of 18 or more on the Hamilton rating scale, this being the threshold value for confirming the existence of moderate depression. However, analysis of variance showed an increase in mental dullness, agitation and somatization disorder. Dullness was related to the extent of anemia and the number of sickle-cell crises per year. Treatment had an effect on agitation in patients, with pentoxyfylline having a soothing effect unlike cinepazide maleate. Women complained of insomnia in the middle of the night and somatic anxiety and presented higher total scores than men. Men exhibited a higher degree of mental dullness. The findings of this preliminary study indicate that while not associated with frank depression, the sickle-cell gene has psychological repercussions on various depressive parameters and that these patients can benefit from treatment with pentoxyfylline.