Brain lithium levels and effects on cognition and mood in geriatric bipolar disorder: a lithium-7 magnetic resonance spectroscopy study.
OBJECTIVE
The authors investigated the relationship between brain lithium, serum lithium and age in adult subjects treated with lithium. In addition, the authors investigated the association between brain lithium and serum lithium with frontal lobe functioning and mood in a subgroup of older subjects.


METHODS
Cross-sectional assessment.


METHODS
McLean Hospital's Geriatric Psychiatry Research Program and Brain Imaging Center; The Division of Psychiatry, Boston University School of Medicine.


METHODS
Twenty-six subjects, 20 to 85 years, with Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition-TR bipolar disorder (BD), currently treated with lithium.


METHODS
All subjects had measurements of mood (Hamilton Depression Rating Scale [HDRS] and Young Mania Rating Scale) and serum and brain lithium levels. Brain lithium levels were assessed using lithium Magnetic Resonance Spectroscopy. Ten subjects older than 50 years also had assessments of frontal lobe functioning (Stroop, Trails A and B, Wis. Card Sorting Task).


RESULTS
Brain lithium levels correlated with serum lithium levels for the group as a whole. However, this relationship was not present for the group of subjects older than 50. For these older subjects elevations in brain (but not serum) lithium levels were associated with frontal lobe dysfunction and higher HDRS scores. The higher HDRS were associated with increased somatic symptoms.


CONCLUSIONS
Frontal lobe dysfunction and elevated depression symptoms correlating with higher brain lithium levels supports conservative dosing recommendations in bipolar older adults. The absence of a predictable relationship between serum and brain lithium makes specific individual predictions about the "ideal" lithium serum level in an older adult with BD difficult.
Forester
Brent P
BP
Geriatric Psychiatry Research Program, McLean Hospital, 115 Mill Street, Belmont, MA 02478, USA. bforester@mclean.harvard.edu
Streeter
Chris C
CC
Berlow
Yosef A
YA
Tian
Hua
H
Wardrop
Megan
M
Finn
Chelsea T
CT
Harper
David
D
Renshaw
Perry F
PF
Moore
Constance M
CM
D000328:Adult; D000339:Affect / Q000187:drug effects; D017668:Age of Onset; D000368:Aged; D000369:Aged, 80 and over; D014150:Antipsychotic Agents / Q000627:therapeutic use*; D001714:Bipolar Disorder / Q000188:drug therapy* / Q000378:metabolism; D001923:Brain Chemistry; D003071:Cognition / Q000187:drug effects; D005260:Female; D005625:Frontal Lobe / Q000502:physiology; D006801:Humans; D018020:Lithium Compounds / Q000097:blood / Q000378:metabolism / Q000627:therapeutic use*; D009682:Magnetic Resonance Spectroscopy; D008297:Male; D008875:Middle Aged; D009483:Neuropsychological Tests
D014150:Antipsychotic Agents; D018020:Lithium Compounds