title: Higher dopamine transporter density in Parkinson's disease patients with depression.
abstract: BACKGROUND
  Depression is a frequent non-motor symptom in Parkinson's disease (PD) with increasing rates with the progression of the disease. Molecular imaging studies have shown a reduction of dopamine transporter (DAT) density in depressed PD patients (dPD); however, DAT role in the pathophysiology of PD depression is not clear since clinical matching was inappropriate and DAT reduction could be attributed to PD severity.
  
  
  OBJECTIVE
  To further examine the role of DAT in PD depression, this study compared thoroughly matched depressed vs. non-depressed PD patients (ndPD).
  
  
  METHODS
  Twenty PD patients (n = 10 ndPD; n = 10 dPD) matched for age and disease severity were submitted to brain SPECT imaging with [(99m)Tc]-TRODAT-1, a DAT radioligand. DAT-binding potential was calculated using regions of interest bilaterally drawn in the striatum, caudate, and putamen. Depression was defined according to Beck Depression Inventory (BDI; cut-off >18).
  
  
  RESULTS
  Mean BDI scores were higher in dPD (25.0 +/- 5.6) than in ndPD patients (8.0 +/- 1.9, p < 0.0001). DAT density was greater on dPD especially in the left caudate (dPD 0.87 +/- 0.19 vs. ndDP 0.69 +/- 0.18, p = 0.02) and right putamen (dPD 0.37 +/- 0.07 vs. ndPD 0.28 +/- 0.13, p = 0.03) than in ndPD patients.
  
  
  CONCLUSIONS
  Our results suggest that in vivo DAT density is increased in dPD patients as compared to ndPD, suggesting that DAT is implicated in the pathophysiology of PD depression.
authors.affiliation: Instituto Israelita de Ensino e Pesquisa (IIEP), Hospital Israelita Albert Einstein (HIAE), Francisco Morato ave, 4293, Postal Code 05521-000, Sao Paulo, Brazil. cf.andre@gmail.com
authors.forename: Andre C
authors.initials: AC
authors.lastname: Felicio
authors.forename: Tais S
authors.initials: TS
authors.lastname: Moriyama
authors.forename: Clecio
authors.initials: C
authors.lastname: Godeiro-Junior
authors.forename: Ming C
authors.initials: MC
authors.lastname: Shih
authors.forename: Marcelo Q
authors.initials: MQ
authors.lastname: Hoexter
authors.forename: Vanderci
authors.initials: V
authors.lastname: Borges
authors.forename: Sonia M A
authors.initials: SM
authors.lastname: Silva
authors.forename: Edson
authors.initials: E
authors.lastname: Amaro-Junior
authors.forename: Luiz A F
authors.initials: LA
authors.lastname: Andrade
authors.forename: Henrique B
authors.initials: HB
authors.lastname: Ferraz
authors.forename: Rodrigo A
authors.initials: RA
authors.lastname: Bressan
mesh_terms: D000368:Aged; D001921:Brain / Q000000981:diagnostic imaging / Q000187:drug effects / Q000378:metabolism*; D016022:Case-Control Studies; D003863:Depression / Q000000981:diagnostic imaging / Q000188:drug therapy / Q000209:etiology / Q000378:metabolism* / Q000473:pathology; D015259:Dopamine Agents / Q000494:pharmacology / Q000627:therapeutic use; D050483:Dopamine Plasma Membrane Transport Proteins / Q000378:metabolism*; D005260:Female; D006801:Humans; D007980:Levodopa / Q000494:pharmacology / Q000627:therapeutic use; D008297:Male; D008875:Middle Aged; D015609:Organotechnetium Compounds / Q000493:pharmacokinetics; D010300:Parkinson Disease / Q000150:complications / Q000188:drug therapy; D011485:Protein Binding / Q000187:drug effects; D019275:Radiopharmaceuticals / Q000493:pharmacokinetics; D018709:Statistics, Nonparametric; D015899:Tomography, Emission-Computed, Single-Photon / Q000379:methods; D014326:Tropanes / Q000493:pharmacokinetics
chemical_list: D015259:Dopamine Agents; D050483:Dopamine Plasma Membrane Transport Proteins; D015609:Organotechnetium Compounds; D019275:Radiopharmaceuticals; D014326:Tropanes; C104196:technetium Tc 99m TRODAT-1; D007980:Levodopa