David Baxter PhD
Late Founder
Bipolar disorder and schizophrenia show genetic overlap
09 February 2007
Am J Psych 2007; 164: 236?247
Research findings suggest that mood-incongruent psychotic symptoms may arise in patients with bipolar disorder due to genetic variation within chromosomes previously linked to schizophrenia.
In their study of 708 families and 1561 bipolar disorder patients, James Potash, from Johns Hopkins Hospital in Baltimore, Maryland, USA, and colleagues found that mood-incongruent psychotic features were associated with a more severe course of illness, familial aggregation, and suggestive linkage to two chromosomal regions.
Bipolar I disorder patients with mood-incongruent psychotic features were more likely to have been hospitalized, attempted suicide, and to have a history of substance abuse or dependence than those with mood-congruent or no psychosis. They also had lower Global Assessment Scale scores, at 63.5 versus 69.3 and 68.5, respectively.
Familial aggregation analysis carried out on 708 bipolar I disorder patients and 1224 of their first-degree relatives showed that patients with mood-incongruent psychotic features were significantly more likely to have relatives with these features than the other bipolar patients, at 21.5% and 12.0%, respectively.
Restricting the analysis to bipolar I disorder first degree relatives increased the aggregation, at 29.8% versus 14.4%.
The researchers then genotyped 2899 individuals. Of these, 2034 had a major mood disorder, with 322 experiencing mood-incongruent symptoms.
The presence of mood-incongruent psychotic features was linked to chromosomes 13q21-33 and 2p11-q14. The logarithm of the odds ratios and their increase from baseline met "empirical genome-wide suggestive criteria for significance," the team notes in the American Journal of Psychiatry.
"The 13q21-33 finding supports prior evidence of bipolar disorder/schizophrenia overlap in this region, while the 2p11-q14 finding is, to the author's knowledge, the first to suggest that this schizophrenia linkage region might also harbor a bipolar disorder susceptibility gene," say Potash et al.
"Our results support the validity of mood-incongruent psychosis as a subset of bipolar disorder with increased clinical severity and closer ties to putative psychosis vulnerability genes shared with schizophrenia."
Abstract
09 February 2007
Am J Psych 2007; 164: 236?247
Research findings suggest that mood-incongruent psychotic symptoms may arise in patients with bipolar disorder due to genetic variation within chromosomes previously linked to schizophrenia.
In their study of 708 families and 1561 bipolar disorder patients, James Potash, from Johns Hopkins Hospital in Baltimore, Maryland, USA, and colleagues found that mood-incongruent psychotic features were associated with a more severe course of illness, familial aggregation, and suggestive linkage to two chromosomal regions.
Bipolar I disorder patients with mood-incongruent psychotic features were more likely to have been hospitalized, attempted suicide, and to have a history of substance abuse or dependence than those with mood-congruent or no psychosis. They also had lower Global Assessment Scale scores, at 63.5 versus 69.3 and 68.5, respectively.
Familial aggregation analysis carried out on 708 bipolar I disorder patients and 1224 of their first-degree relatives showed that patients with mood-incongruent psychotic features were significantly more likely to have relatives with these features than the other bipolar patients, at 21.5% and 12.0%, respectively.
Restricting the analysis to bipolar I disorder first degree relatives increased the aggregation, at 29.8% versus 14.4%.
The researchers then genotyped 2899 individuals. Of these, 2034 had a major mood disorder, with 322 experiencing mood-incongruent symptoms.
The presence of mood-incongruent psychotic features was linked to chromosomes 13q21-33 and 2p11-q14. The logarithm of the odds ratios and their increase from baseline met "empirical genome-wide suggestive criteria for significance," the team notes in the American Journal of Psychiatry.
"The 13q21-33 finding supports prior evidence of bipolar disorder/schizophrenia overlap in this region, while the 2p11-q14 finding is, to the author's knowledge, the first to suggest that this schizophrenia linkage region might also harbor a bipolar disorder susceptibility gene," say Potash et al.
"Our results support the validity of mood-incongruent psychosis as a subset of bipolar disorder with increased clinical severity and closer ties to putative psychosis vulnerability genes shared with schizophrenia."
Abstract
