Unrecognized glucose intolerance is not associated with depression. Screening for Impaired Glucose Tolerance study 3 (SIGT 3).

AIMS: To understand the metabolic and temporal links in the relationship between diabetes and depression, we determined the association between depressive symptoms and unrecognized glucose intolerance. METHODS: In a cross-sectional study, 1047 subjects without known diabetes were screened for diabetes or pre-diabetes using the oral glucose tolerance test and for depressive symptoms using the Patient Health Questionnaire (PHQ). RESULTS: Mean age was 48 years, body mass index 30 kg/m(2); 63% were female, 54% black, 11% previously treated for depression and 10% currently treated; 5% had diabetes and 34% pre-diabetes. Median PHQ score was 2 (interquartile range 0-5). Depressive symptoms did not increase with worsening glucose tolerance, after adjusting for age, sex, ethnicity, body mass index, family history, exercise, education and depression treatment. CONCLUSIONS: There is no association between depressive symptoms and unrecognized glucose intolerance. However, it remains possible that diagnosed diabetes, with its attendant health concerns, management issues, and/or biological changes, may be a risk for subsequent development of depression. Thus, patients with newly diagnosed diabetes should be counselled appropriately and monitored for the development of depression.

Limbic-hypothalamic-pituitary-adrenal axis activity and ventricular-to-brain ratio studies in affective illness and schizophrenia.

Some investigators have speculated that structural brain alterations observed in some psychiatric patients might be related to increased limbic-hypothalamic-pituitary-adrenal axis (LHPA) activity. To explore this hypothesis, we prospectively studied 166 research volunteers (19 patients with research diagnostic criteria (RDC) major depression, 9 patients with RDC bipolar depression, 45 patients with RDC schizophrenia, and 94 RDC normal controls), examining the relationship between magnetic resonance image-determined ventricular-to-brain ratio (VBR) and indices of LHPA axis function (cerebrospinal fluid (CSF) corticotropin-releasing factor (CRF), CSF adrenocorticotropic hormone (ACTH), and 24-hour urinary-free cortisol secretion). We observed no significant differences in mean VBR among the three patient groups and the normal control volunteers. Of the indices of LHPA activity, only CSF CRF concentrations distinguished the four subject groups, with CSF CRF being significantly elevated in the more severely depressed major depression patients. Indices of LHPA activity were not significantly correlated with VBR in any of the three patient groups or in the normal volunteers. These preliminary results suggest that VBR is not highly associated with alterations in LHPA activity, at least as determined cross-sectionally. Further longitudinal studies with reference to diagnostic subtypes, severity, symptom profiles, and more specific neuroanatomic regions may allow the elucidation of possible relationships between LHPA pathology and structural brain alterations.