Caudate nucleus volumes and genetic determinants of homocysteine metabolism in the prediction of psychomotor speed in older persons with depression.
OBJECTIVE
The authors sought to determine whether caudate nucleus volumes or specific genotypes predict psychomotor slowing in older persons with depression.


METHODS
Forty-seven persons with depression (mean age=51.8 years, SD=12.4) and 20 healthy volunteers (mean age=56.1 years, SD=9.8) underwent clinical assessments, a neuropsychological test of psychomotor speed (part A of the Trail Making Test), high-resolution magnetic resonance imaging scans, and genotyping for the apolipoprotein E epsilon4 allele and a mutation of the methylenetetrahydrofolate reductase enzyme.


RESULTS
Multivariate analyses revealed that psychomotor speed was uniquely predicted by age, a diagnosis of depression, right caudate nucleus volume, and mutation of the methylenetetrahydrofolate reductase enzyme.


CONCLUSIONS
Psychomotor slowing, a key clinical and cognitive phenomenon in older persons with depression, is predicted by reduced caudate nucleus volumes and genetic determinants of homocysteine metabolism.
Naismith
Sharon
S
School of Psychiatry, University of New South Wales, PO Box 1, Rozelle NSW 2039, Sydney, Australia. Sharon_Naismith@wsahs.nsw.gov.au
Hickie
Ian
I
Ward
Philip B
PB
Turner
Keelin
K
Scott
Elizabeth
E
Little
Craig
C
Mitchell
Philip
P
Wilhelm
Kay
K
Parker
Gordon
G
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001057:Apolipoproteins E / Q000378:metabolism; D002421:Caudate Nucleus / Q000033:anatomy & histology* / Q000201:enzymology / Q000378:metabolism*; D003865:Major Depressive Disorder / Q000175:diagnosis* / Q000235:genetics* / Q000378:metabolism; D005260:Female; D005838:Genotype; D006710:Homocysteine / Q000235:genetics* / Q000378:metabolism*; D006801:Humans; D008279:Magnetic Resonance Imaging; D008297:Male; D042965:Methylenetetrahydrofolate Reductase (NADPH2); D008875:Middle Aged; D009483:Neuropsychological Tests; D000587:Oxidoreductases Acting on CH-NH Group Donors / Q000378:metabolism; D011596:Psychomotor Disorders / Q000175:diagnosis*
D001057:Apolipoproteins E; D006710:Homocysteine; D000587:Oxidoreductases Acting on CH-NH Group Donors; D042965:Methylenetetrahydrofolate Reductase (NADPH2)