Clinical diagnoses in young offspring from eastern Québec multigenerational families densely affected by schizophrenia or bipolar disorder

Abstract

. Clinical diagnoses in young offspring from eastern Que´bec multigenerational families densely affected by schizophrenia or bipolar disorder.Objective: The follow-up since 1989 of a large sample of multigenerational families of eastern Que´bec that are densely affected by schizophrenia (SZ) or bipolar disorder (BP) has permitted to look at the rates of DSM diagnoses in the young offspring of a SZ parent (HRSZ) and of a BP parent (HRBP) who had an extremely loaded family history. Method: The sample (average age of 17.5, SD 4.5) consisted of 54 highrisk offspring (HR) having one parent affected by a DSM-IV SZ or BP. The parents descended from 21 multigenerational families that constitute a quasi-total sample of such kindred in eastern Que´bec. The HRs were administered a lifetime best estimate DSM-IV diagnosis. Results: We observed that the rates, the diversity of diagnoses, the high comorbidity, the severity and the age of onset of the clinical diagnoses tended to be similar with those already reported in the offspring of affected parents with a low familial loading. Although the sample size was small, HRSZ and HRBP also tended to show similarities in their clinical status. Conclusion: Overall, taking into account methodological limitations, the observation early in life of some shared characteristics among HRSZ and HRBP in terms of non-psychotic diagnosis may be congruent with the accumulating evidence that several phenotypic features are shared in adulthood by the two major psychoses. Significant outcomes• Offspring at high genetic risk of major psychosis displayed early in life non-psychotic DSM disorders warranting a consultation.• Various and highly comorbid disorders were observable in these offspring at extreme genetic risk.• HRSZ and HRBP showed similarities in their clinical status. Limitations• Normal control group from the general population was absent.• Small sample size may have prevented detection of differences between HRSZ and HRBP.• Caution is required before generalizing findings to the offspring of an ill parent from the general population.Re-use of this article is permitted in accordance with the Creative Commons Deed, Attribution 2.5, which does not permit commercial exploitation.

Chromosome 13q13–q14 locus overlaps mood and psychotic disorders: the relevance for redefining phenotype

“…Although family studies suggest little co-aggregation of SZ and BP, 1 an observable trend is that many of the genetic vulnerability loci may be shared by SZ and BP, which challenges the traditional Kraepelinian dichotomy and current nosology. 2 -8 This trend is congruent with the observations that BP and SZ share early in life, 9,10 and later on, 11,12 several phenotypic features encompassing the neurobiological, neuropsychological and clinical domains. Seemingly in contrast with the evidence of genetic influences crossing the SZ and BP DSM boundaries, a second emerging pattern of findings suggests distinct subgroups within the SZ or within the BP diagnosis, such as the negative symptoms and of SZ found associated with a 6p locus, 13,14 or the psychotic BP subtype with a 16p locus or 13q21 -q33.…”

Toward a Comprehensive Clinical Staging Model for Bipolar Disorder: Integrating the Evidence

“…10,44,45 Granted there are intermediate clinical presentations and reports of overlapping genetic and neurobiological findings; however, in part this reflects the broadening of the BD concept 20,46 and assortative mating. 47,48 Another challenge to the proposal of simply generalizing the early psychosis model to mood disorders is that BD is not diagnosed until the manifestation of the first-activated (hypomanic or manic) episode; however, the classical disorder almost always starts with depressive episodes. 49 Moreover, depressive episodes typically antecede the first diagnosable activated episode by many years.…”

The Dutch Bipolar Offspring Study: 12-Year Follow-Up

“…More recently, two review articles on bipolar offspring reported elevated but varying prevalence rates of bipolar disorder (ranging from 3% to 27%), mood disorders (ranging from 5% to 67%), and non-mood disorders (ranging from 5% to 52%) (2,3). However, these studies could not fully address the development and early course of bipolar disorder and other mood disorders because they used either a crosssectional design or a longitudinal design without follow-up into adulthood (1)(2)(3)(4)(5)(6)(7)(8)(9)(10)(11)(12). We report here on one of the largest prospective bipolar offspring studies with a follow-up into adulthood: the 12-year follow-up of the Dutch bipolar offspring cohort (7,10,12).…”