β‐Adrenoceptor binding defects in cell lines from families with manic‐depressive disorder

Summary Binding of 125 I‐iodohydroxybenzylpindolol to β ‐adrenoceptors has been examined in lymphoblastoid cell lines from members of 5 families affected by manic‐depressive disorder. Cell lines from 6 manic‐depressives, 7 unaffected relatives and 11 non‐psychiatric controls were examined. Binding was reduced to less than half of control values in cell lines from 4 out of 6 manic‐depressives and only 1 out of 18 unaffected relatives or controls. All the cell lines with reduced β ‐adrenoceptor binding came from 3 families; members of the remaining 2 families showed normal binding. These findings suggest that genetic heterogeneity is present in manic‐depressive disorder and that a β ‐adrenoceptor defect may influence genetic susceptibility to the disorder.