Table 1 Summary of key evidence at the forefront of the boundaries of schizophrenia, schizoaffective disorder, and bipolar I disorder debate
Evidence | Conclusion |
|---|---|
Family studies | |
Tsuang et al., 1980 [26]; Mortensen et al., 2003 [27]; Lichtenstein et al., 2009 [28]; Van Snellenberg et al., 2009 [29]; Dean et al., 2010 [30] | Increased risk for bipolar disorder in families of individuals with schizophrenia and for schizophrenia in families of individuals with bipolar disorder |
Schizophrenia and bipolar disorder linked to unipolar depression | |
Kendler et al., 1998 [33] | Roscommon Family Study; vulnerability to psychosis may extend across schizophrenia, major depression, and bipolar disorder |
Twin studies | |
Cardno et al., 2002 [34] | Significant genetic correlations between schizophrenia, schizoaffective disorder, and mania |
Genome wide association studies (GWAS) | |
O’Donovan et al., 2009 [14]; Green et al., 2009 [35]; Williams et al., 2010 [36]; Lee et al., 2012 [37] | ZNF804A and CACNA1C may influence risk for both schizophrenia and bipolar disorder |
Brain morphology | |
Ellison-Wright and Bullmore, 2010 [38]; Arnone et al., 2009 [39]; Rimol et al., 2012 [40] | Some overlapping white and gray matter deficits, but cortical reductions exclusive to schizophrenia |
McIntosh et al., 2006 [41] | Genetic liability for gray matter reductions in DLPRC and VLPFC exclusively in schizophrenia |
Hulshoff et al., 2012 [42] | Overlapping white matter volume and areas of thin cortex suggest shared neurodevelopment |
Pharmacotherapeutics | |
Suppes et al., 1991 [43]; Schulz et al., 1999 [44]; Baldessarini et al., 1999 [45]; Leucht et al., 2006 [46] | Lithium can be used as monotherapy or for augmentation of antipsychotics in bipolar disorder but ineffective in schizophrenia |
Casey et al., 2003 [47] | Divalproex prescribed for acute mania but minimal efficacy in schizophrenia |
Tiihonen et al., 2003 [48]; Kremer et al., 2004 [49]; Zoccali et al., 2007 [50]; Goff et al., 2007 [51] | Initial reports of lamotrigine positive in add-on schizophrenia, but no better than placebo in multicenter, randomized trials |
Post et al., 1999 [52] | Unexpected broad efficacy across psychotic disorders for second generation antipsychotics |