Joel Hamovit

Lithium in children of lithium-responding parents

Six offspring of manic-depressive patients, whose parents were lithium responders, were selected on the basis of their incapacitating psychopathology for treatment with lithium. The children ranged in age from 6 to 12. A double-blind, crossover design was used over 16-18 weeks. Weekly ratings were done, and average evoked potentials (EPs) were measured at each crossover. Two children diagnosed as having a bipolar affective disorder had a clear-cut response to lithium and were strong augmenters on the EP. This, taken together with the similarity of the EP changes on lithium to those occurring in adult patients treated with lithium, supports a physiological parallel between bipolar affective illness in adults and children.

Supersensitivity to melatonin suppression by light in young people at high risk for affective disorder. A preliminary report

Affective illness aggregates in families and appears to be heritable. Bipolar affective patients have been found to be supersensitive to the suppressive effect of light on the nocturnal secretion of melatonin, both in ill and well states. We tested young people aged 15 to 25 years with one manic-depressive parent (n = 18), major affective disorder on both sides of the family (n = 7), and age-matched controls (n = 20). The subjects in the high-risk groups were more likely to show supersensitivity in melatonin response to light at night than controls. Follow-up studies are necessary to assess the predictive value of this response.

A family study of rapid-cycling bipolar illness

Twenty-nine out of 195 bipolar/episodic schizoaffective patients were judged to be rapid-cyclers (15%). Twenty-five of the 29 were female (86%). The age-corrected morbid risk for major affective disorder was 23.5% in 179 relatives of rapid-cyclers and 31.0% in 189 relatives of matched non-rapid cyclers (chi 2 = 2.6, NS). The prevalence of rapid-cycling itself was also not different in the two groups of relatives. Rapid-cycling thus appears to arise from factors which are separable from the genetic vulnerability to bipolar illness and which do not lead to aggregation within families.

A bipolar pedigree series for genomic mapping of disease genes: Diagnostic and analytic considerations

Twenty-one multiplex bipolar (BP) families, suitable for linkage studies, are described. The families include 365 informative persons (whose genotypes can be determined from available DNA samples), 154 of whom have BP, schizoaffective or recurrent unipolar diagnoses. The power of such a series to detect linkage is estimated through simulations under assumptions concerning the inheritance of BP illness, the genetic distances between the illness locus and markers, and marker heterozygosity. It is concluded that this series has greater than 50% power to detect linkage when only 25% of the families are linked to the locus under study. This paper is intended to serve as an introduction to a systematic genomic search for genes causing vulnerability to BP disease among these families.