Risk of Mental Illness Higher If Both Parents Mentally Ill
Research suggests information may be useful for personal decision making
TUESDAY, March 2 (HealthDay News) -- People whose parents are both diagnosed with schizophrenia or bipolar disorder are at much higher risk of developing these and other psychiatric disorders, according to a study in the March issue of the Archives of General Psychiatry.
Irving I. Gottesman, Ph.D., from the University of Minnesota Medical School in Minneapolis, and colleagues analyzed population-based data from 2.7 million Danish individuals to examine the risk of schizophrenia, bipolar disorder, unipolar depressive disorder, or any diagnosis in offspring 10 to 52 years old where both parents have been diagnosed with schizophrenia or bipolar disorder.
The researchers found that the risk of schizophrenia was significantly higher in children where both parents were diagnosed with schizophrenia (27.3 versus 7.0 percent for one parent diagnosed and 0.86 percent for neither parent diagnosed). Similarly higher risks were found for bipolar disorder (24.9 versus 4.4 percent for one parent diagnosed and 0.48 percent for neither parent diagnosed). The maximal risk of any psychiatric disorder was 67.5 percent when both parents were diagnosed with schizophrenia, and 44.2 percent when both parents were diagnosed with bipolar disorder.
The results may be useful for "personal decision making with regard to marriage, child bearing, adoption, and one's own prospects for the future," Gottesman and colleagues write. "Evidence must converge from twin, family, and adoption studies to convince the scientist that the largest part of the familiality we observed in this study for schizophrenia and bipolar disorder was indeed attributable to genetic factors, and such data exist in abundance."