RESUMEN
BACKGROUND: Many lines of evidence suggest the role of serotonin transporter (SERT)-mediated reuptake of serotonin in the pathophysiology and treatment of major depressive disorder (MDD). This study aimed to examine whether the pretreatment of SERT binding potential or SERT binding ratio between terminal projection regions relative to the midbrain raphe nuclei was associated with treatment outcomes to SERT-targeted antidepressants. METHODS: We recruited 39 antidepressant-naïve patients with MDD and 39 heathy controls. Positron emission tomography with N,N-dimethyl-2-(2-amino-4-[(18)F]fluorophenylthio)benzylamine (4-[(18)F]-ADAM) was used to measure in vivo SERT availability prior to antidepressant treatment. The 21-item Hamilton Depression Rating Scale (HDRS) was use to assess the severity of depression from baseline to week 6. All the patients with MDD had HDRS scores of 18 or more. RESULTS: Pretreatment SERT binding in the thalamus and striatum positively correlated with an early reduction in HDRS scores at week 3. Nonresponders and dropout patients showed a proportionate reduction in SERT binding in the terminal projection regions and midbrain compared to healthy controls. In contrast, a disproportionate reduction in SERT binding in the terminal projection regions relative to midbrain was observed in responders. CONCLUSIONS: The results of this study suggested that a disproportionate reduction in SERT binding between terminal projection regions and midbrain may predict better treatment outcomes in patients with MDD.
Asunto(s)
Antidepresivos/uso terapéutico , Encéfalo/metabolismo , Trastorno Depresivo Mayor/tratamiento farmacológico , Trastorno Depresivo Mayor/metabolismo , Tomografía de Emisión de Positrones , Proteínas de Transporte de Serotonina en la Membrana Plasmática/metabolismo , Adulto , Bencilaminas/administración & dosificación , Encéfalo/diagnóstico por imagen , Cuerpo Estriado/metabolismo , Trastorno Depresivo Mayor/diagnóstico por imagen , Femenino , Humanos , Masculino , Mesencéfalo/metabolismo , Persona de Mediana Edad , Radiofármacos/administración & dosificación , Tálamo/metabolismo , Resultado del Tratamiento , Adulto JovenRESUMEN
Although cobalamin deficiency is widely known and usually presents with hematologic and neuropsychiatric manifestations, the psychiatric symptoms are not usually the predominant manifestation. We describe a young single male vegetarian who developed a cobalamin-induced psychotic episode without preceding neurologic manifestations and without any hematologic symptoms. He recovered after a short course of antipsychotics and oral cobalamin supplementation and remained asymptomatic and functionally independent at 1 year of follow-up.