Familial aggregation of delusional depression: re-examination in a recent family study.
BACKGROUND
Delusional (D-MDD) and nondelusional depression (ND-MDD) differ in clinical presentation, biological abnormalities, course of illness, and treatment response. Family data, however, have been less consistent regarding differential risk both for any major depression (MDD) and specifically D-MDD in relatives of D-MDD probands. In an earlier family study, we observed a 1.5-fold increase in rates of any MDD, specificity of transmission of D-MDD, and increased rates of bipolar disorders in relatives of D-MDD compared to relatives of ND-MDD probands. In a new family study, we attempted to replicate these findings.


METHODS
A family study of 361 directly interviewed adult first-degree relatives (FDRs) of 163 probands (118 with MDD and 45 screened normal controls) was used to examine familial aggregation of any MDD, D-MDD, and bipolarity by proband delusional status.


RESULTS
Compared to FDRs of ND-MDD probands, FDRs of D-MDD probands were at modestly increased risk for any MDD. These results were unaffected by adjustment for proband ascertainment source, comorbidity, or whether probands had chronologically primary MDD. There was a trend toward increased rates of broadly defined bipolarity (bipolar I, bipolar II, or cyclothymia) in FDRs of D-MDD compared to FDRs of ND-MDD probands.


CONCLUSIONS
Results from the present study were broadly consistent with those from our previous work. While other lines of evidence for D-MDD as a distinct subtype are more compelling than family data, it would be of methodologic interest to identify sources of inconsistency across studies in findings concerning the familial aggregation of delusional depression.
Goldstein
R B
RB
Department of Psychiatry, College of Physicians and Surgeons of Columbia University, New York, New York, USA. RBGOLDST@hsc.vcu.edu
Horwath
E
E
Wickramaratne
P J
PJ
Wolk
S I
SI
Warner
V
V
Weissman
M M
MM
D000293:Adolescent; D000328:Adult; D000368:Aged; D003702:Delusions / Q000235:genetics*; D003866:Depressive Disorder / Q000235:genetics*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D012720:Severity of Illness Index