2012 Revisiting Thyroid Hormones in Schizophrenia, Journal of Thyroid Research, Nadine Correia Santos,1,2 Patrício Costa,1,2 Dina Ruano,1,3 António Macedo,4 Maria João Soares,4 José Valente,4 Ana Telma Pereira,4 Maria Helena Azevedo,4 and Joana Almeida Palha The timing and adequate amount of TH’s (Thyroid hormones) action is crucial for the normal neurodevelopment and maturation of the central nervous system (CNS) and for proper functioning of the adult brain . Given their described roles, it is not entirely unexpected that a link between TH and psychiatric disease may be considered [24, 26]. Among others, T3 promotes differentiation in astrocytes, mediates cerebellar astrocyte and neuronal proliferation, and participates in the organization of extracellular matrix molecules via astrocytes [15, 135]… Recently, Scanlan and team (review ) have explored a similar neurotransmitter function for 3-iodothyronamine (T(1)AM), a molecule proposed to result from a unique biosynthetic deiodination pathway starting from the decarboxylation products of either T4 or rT3. The hormone T3 is reported to accumulate in nerve endings reaching high concentrations in the synaptosome [137, 138] and being released from it in a Ca2+-dependent mechanism . In in vitrostudies T1AM has been found to block the transporters for the amines/neurotransmitters dopamine, norepinephrine, and serotonin. Interestingly, T1AM binds with high affinity to the trace-amine-associated receptor (TAAR) [136, 140], a class of G-protein-coupled receptors, and genetic linkage studies have shown a significant association between the TAAR gene and susceptibility to schizophrenia [141
2012 Hypothyroxinemia (Low T4) in Pregnancy is Related with Attention Deficit Hyperactivity Disorder, Miriam Muñoz Lopez, Contemporary Trends in ADHD Research, www.intechopen.com
2007 Iodine deficiency, (accompanying maternal hypothyroxinemia (low T4), and brain development in the first half of pregnancy. Public Health Nutrition, Cambridge Journals Online, Gabriella Morreale de Escobar, Maria Jesus Obregon and Francisco Escobar del Rey, …even a relatively mild and transient hypothyroxinemia during corticogenesis, which takes place mostly before mid-gestation in humans, affects the migration of radial neurons, which settle permanently in heterotopic locations within the cortex and hippocampus.
2006 The down-regulation of transthyretin found in patients with schizophrenia is of special interest to the researchers. Transthyretin is a thyroid hormone–binding protein that transports thyroxine (T4) from the bloodstream to the brain. They suggest that the reduced level of transthyretin in CSF results in a lower thyroxine transport in brains of patients with schizophrenia. They further point out that thyroid dysfunction is relatively common in patients with schizophrenia and other psychiatric disorders, and hypothesize that thyroid dysfunction may somehow be genetically linked to schizophrenia and other psychiatric disorders…Interestingly, long-term administration of clozapine has been shown to induce transthyretin expression in rat hippocampus and cerebral cortex, implying that clozapine enhances central nervous system thyroxine function, supporting the clinical relevance of transthyretin in the early pathophysiology of schizophrenia. Transthyretin has also been found to be differentially expressed in CSF of several other neurological and psychiatric diseases.