Haptoglobin types and unipolar depression

Haptoglobin (Hp) has been used in association studies with unipolar depression and has led to investigations on the possible association of Hp genotypes with disease. Because of the reported association between the Hp-2 allele and depression we phenotyped 65 elderly patients with unipolar depression and 40 elderly individuals without mental disorders. We failed to find an association between either of the Hp alleles and unipolar depression. The Hp2 gene frequencies for the depressed patients and the comparison group were 0.585 and 0.550, respectively, and these values were not significantly different. Both values were within the gene frequency range reported for Caucasian populations.