Are schizophrenic and bipolar disorders related? A review of family and molecular studies

Biol Psychiatry. 2000 Sep 15;48(6):531-8. doi: 10.1016/s0006-3223(00)00883-0.


Schizophrenic and bipolar disorders are similar in several epidemiologic respects, including age at onset, lifetime risk, course of illness, worldwide distribution, risk for suicide, gender influence (men and women at equal risk for both groups of disorders), and genetic susceptibility. Despite these similarities, schizophrenia and bipolar disorders are typically considered to be separate entities, with distinguishing clinical characteristics, non-overlapping etiologies, and distinct treatment regimens. Over the past three decades, multiple family studies are consistent with greater nosologic overlap than previously acknowledged. Molecular linkage studies (conducted during the 1990s) reveal that some susceptibility loci may be common to both nosologic classes. This indicates that our nosology will require substantial revision during the next decade, to reflect this shared genetic susceptibility, as specific genes are identified.

Publication types

  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, P.H.S.
  • Review

MeSH terms

  • Bipolar Disorder / epidemiology
  • Bipolar Disorder / genetics*
  • Family
  • Genetic Linkage
  • Genetic Markers
  • Genetic Predisposition to Disease
  • Humans
  • Lod Score
  • Schizophrenia / epidemiology
  • Schizophrenia / genetics*
  • Twin Studies as Topic


  • Genetic Markers