title: Midbrain serotonin and striatum dopamine transporter binding in double depression: a one-year follow-up study.
abstract: Data on neurobiological differences between major depression (MD) and double depression (DD) are scarce. We examined the striatum dopamine (DAT) and midbrain serotonin transporter (SERT) binding of [123I] nor-beta-CIT in DD patients (n=8) and compared it to that in MD patients (n=11) and healthy controls (n=19). Drug-naïve patients and controls were imaged by single-photon emission computed tomography at baseline, and the patients also after one year of psychodynamic psychotherapy. Both DD and MD groups had lower midbrain [123I] nor-beta-CIT binding compared with the controls. Baseline 17-item Hamilton Depression Rating Scale (HAM-D-17) scores significantly decreased in both groups after one year of psychotherapy (DD: t=3.55, p=0.009; MD: t=5.86, p<0.001). No differences between the DD and MD groups were observed in age-adjusted baseline striatum or midbrain [123I] nor-beta-CIT binding or its change during psychotherapy. Age-adjusted baseline striatum [123I] nor-beta-CIT binding correlated inversely with the duration of both dysthymia (rho=-0.76, p=0.03) and MD (rho=-0.83, p=0.01) in the DD group. No such finding was observed in the MD group (rho=0.26, p=0.44). Baseline HAM-D-17 did not correlate with the change in striatum or midbrain [123I] nor-beta-CIT binding in either group. In conclusion, our findings suggest that when using midbrain [123I] nor-beta-CIT binding as a marker of SERT binding, no differences are detectable between patients with DD and MD. However, low striatum [123I] nor-beta-CIT binding, a marker of DAT binding, may be associated with a longer illness duration in dysthymia.
authors.affiliation: Department of Psychiatry, Kuopio University Hospital, 70210 Kuopio, Finland. Soili.Lehto@kuh.fi
authors.forename: Soili M
authors.initials: SM
authors.lastname: Lehto
authors.forename: Tommi
authors.initials: T
authors.lastname: Tolmunen
authors.forename: Jyrki
authors.initials: J
authors.lastname: Kuikka
authors.forename: Minna
authors.initials: M
authors.lastname: Valkonen-Korhonen
authors.forename: Mikko
authors.initials: M
authors.lastname: Joensuu
authors.forename: Pirjo I
authors.initials: PI
authors.lastname: Saarinen
authors.forename: Ritva
authors.initials: R
authors.lastname: Vanninen
authors.forename: Pasi
authors.initials: P
authors.lastname: Ahola
authors.forename: Jari
authors.initials: J
authors.lastname: Tiihonen
authors.forename: Johannes
authors.initials: J
authors.lastname: Lehtonen
mesh_terms: D000328:Adult; D001667:Binding, Competitive / Q000187:drug effects; D015415:Biomarkers / Q000032:analysis / Q000378:metabolism; D015283:Citalopram; D003342:Corpus Striatum / Q000000981:diagnostic imaging / Q000378:metabolism* / Q000503:physiopathology; D003865:Major Depressive Disorder / Q000000981:diagnostic imaging / Q000378:metabolism* / Q000503:physiopathology; D004185:Disability Evaluation; D004298:Dopamine / Q000378:metabolism; D050483:Dopamine Plasma Membrane Transport Proteins / Q000378:metabolism*; D015536:Down-Regulation / Q000502:physiology; D019263:Dysthymic Disorder / Q000000981:diagnostic imaging / Q000378:metabolism* / Q000503:physiopathology; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D007457:Iodine Radioisotopes; D008297:Male; D008636:Mesencephalon / Q000000981:diagnostic imaging / Q000378:metabolism* / Q000503:physiopathology; D009483:Neuropsychological Tests; D049268:Positron-Emission Tomography; D011237:Predictive Value of Tests; D011379:Prognosis; D012701:Serotonin / Q000378:metabolism; D050486:Serotonin Plasma Membrane Transport Proteins / Q000378:metabolism*; D017367:Selective Serotonin Reuptake Inhibitors; D013997:Time Factors
chemical_list: D015415:Biomarkers; D015283:Citalopram; D004298:Dopamine; D050483:Dopamine Plasma Membrane Transport Proteins; D007457:Iodine Radioisotopes; D012701:Serotonin; D050486:Serotonin Plasma Membrane Transport Proteins; D017367:Selective Serotonin Reuptake Inhibitors