Relative insulin insensitivity and cortisol secretion in depressed patients

Depression in Polycystic Ovary Syndrome: A Systematic Review and Meta-Analysis

Polycystic ovary syndrome (PCOS) is an endocrine disorder with a broad spectrum of clinical symptoms. Some of the serious complications of PCOS are mental disorders including depression. Therefore, the aim of the meta-analysis was to determine the prevalence, mean level, standardized mean difference and probability of depression based on the research conducted with the Hospital Anxiety and Depression Scale (HADS). A systematic literature search was performed using the following databases: PubMed, EMBASE, Scopus, ClinicalTrials.gov and Google for research published until January 2023. The meta-analysis was conducted on a group of 4002 patients obtained from 19 studies, which met the inclusion criteria (adult pre-menopausal women diagnosed with PCOS, papers on the prevalence of depression or the HADS scoring). According to the research performed, the mean prevalence of depression was 31% (I2 = 93%; p < 0.001), whereas the mean HADS depression score in patients with PCOS was 6.31 (I2 = 93%; p < 0.001). The standardized difference of mean depression scores was SMD = 0.421 (95% confidence interval = 0.17-0.68, I2 = 67%). The overall probability of depression in PCOS patients was more than 2.5-fold higher than in healthy women ((RR: 2.58), confidence interval [1.38-4.85]; I2 = 90%, p < 0.001). The research results imply an increased risk of depressive symptoms in women with PCOS.

PCOS and Depression: Common Links and Potential Targets

PCOS or polycystic ovary syndrome is a common endocrine disorder that occurs during the reproductive age in females. It manifests in the form of a wide range of symptoms including (but not limited to) hirsutism, amenorrhea, oligomenorrhea, obesity, acne vulgaris, infertility, alopecia, and insulin resistance. The incidence of depression in PCOS population is increasing as compared to the general population. Increased depression in PCOS significantly alters the quality of life (QOL) of affected females. Also, self-esteem is found to be low in both depression and PCOS. The loss in self-esteem in such patients can be largely attributed to the associated factors including (but not limited to) obesity, acne, androgenic alopecia, and hirsutism. The reason behind the occurrence of depression in PCOS remains elusive to date. Literature suggests that there is an overlap of clinical symptoms between depression and PCOS. As the symptoms overlap, there is a possibility of common associations between depression, PCOS, and PCOS-associated abnormalities including insulin resistance (IR), obesity, CVD, and androgen excess. Studies demonstrate that depression is an inflammatory disorder marked with increased levels of inflammatory markers. On the other hand, PCOS is also regarded as a pro-inflammatory state that is characterized by increased levels of pro-inflammatory markers. Thus, there is a possibility of an inflammatory relationship existing between depression and PCOS. It is also possible that the inflammatory markers in PCOS can cross the blood-brain barrier (BBB) leading to the development of depression. Through the present review, we have attempted to shed light on common associations/shared links between depression and PCOS with respect to the levels of cortisol, androgen, vitamin D, neurotransmitters, monoaminoxidase (MAO), and insulin-like growth factor-1 (IGF-1). Tracking down common associations between depression and PCOS will help find potential drug therapies and improve the QOL of females with depression in PCOS.

Adjuvant pioglitazone for unremitted depression: Clinical correlates of treatment response

Previous studies suggest that insulin-sensitizing agents could play a significant role in the treatment of major depression, particularly depression in patients with documented insulin resistance or those who are resistant to standard psychopharmacological approaches. This study aimed to assess the effects on depressive symptoms with adjuvant treatment with the PPARγ-agonist pioglitazone. Patients (N=37) with non-psychotic, non-remitting depression receiving standard psychiatric regimens for depression were randomized across an insulin sensitivity spectrum in a 12-week double blind, randomized controlled trial of pioglitazone or placebo. Improvement in depression was associated with improvement in glucose metabolism but only in patients with insulin resistance. An age effect was also shown in that response to pioglitazone was more beneficial in younger aged patients. Study findings suggest differential improvement in depression severity according to both glucose metabolic status and level of depression at baseline. A greater understanding of the reciprocal links between depression and IR may lead to a dramatic shift in the way in which depression is conceptualized and treated, with a greater focus on treating and/or preventing metabolic dysfunction.

Hypothalamic-pituitary-adrenocortical axis: neuropsychiatric aspects

Evidence of aberrant hypothalamic-pituitary-adrenocortical (HPA) activity in many psychiatric disorders, although not universal, has sparked long-standing interest in HPA hormones as biomarkers of disease or treatment response. HPA activity may be chronically elevated in melancholic depression, panic disorder, obsessive-compulsive disorder, and schizophrenia. The HPA axis may be more reactive to stress in social anxiety disorder and autism spectrum disorders. In contrast, HPA activity is more likely to be low in PTSD and atypical depression. Antidepressants are widely considered to inhibit HPA activity, although inhibition is not unanimously reported in the literature. There is evidence, also uneven, that the mood stabilizers lithium and carbamazepine have the potential to augment HPA measures, while benzodiazepines, atypical antipsychotics, and to some extent, typical antipsychotics have the potential to inhibit HPA activity. Currently, the most reliable use of HPA measures in most disorders is to predict the likelihood of relapse, although changes in HPA activity have also been proposed to play a role in the clinical benefits of psychiatric treatments. Greater attention to patient heterogeneity and more consistent approaches to assessing treatment effects on HPA function may solidify the value of HPA measures in predicting treatment response or developing novel strategies to manage psychiatric disease.

The relationship between fasting serum glucose and cerebral glucose metabolism in late-life depression and normal aging

Evidence exists for late-life depression (LLD) as both a prodrome of and risk factor for Alzheimer׳s disease (AD). The underlying neurobiological mechanisms are poorly understood. Impaired peripheral glucose metabolism may explain the association between depression and AD given the connection between type 2 diabetes mellitus with both depression and AD. Positron emission tomography (PET) measures of cerebral glucose metabolism are sensitive to detecting changes in neural circuitry in LLD and AD. Fasting serum glucose (FSG) in non-diabetic young (YC; n=20) and elderly controls (EC; n=12) and LLD patients (n=16) was correlated with PET scans of cerebral glucose metabolism on a voxel-wise basis. The negative correlations were more extensive in EC versus YC and in LLD patients versus EC. Increased FSG correlated with decreased cerebral glucose metabolism in LLD patients to a greater extent than in EC in heteromodal association cortices involved in mood symptoms and cognitive deficits observed in LLD and dementia. Negative correlations in YC were observed in sensory and motor regions. Understanding the neurobiological consequences of diabetes and associated conditions will have substantial public health significance given that this is a modifiable risk factor for which prevention strategies could have an important impact on lowering dementia risk.

Obesity--a neuropsychological disease? Systematic review and neuropsychological model

Obesity is a global epidemic associated with a series of secondary complications and comorbid diseases such as diabetes mellitus, cardiovascular disease, sleep-breathing disorders, and certain forms of cancer. On the surface, it seems that obesity is simply the phenotypic manifestation of deliberately flawed food intake behavior with the consequence of dysbalanced energy uptake and expenditure and can easily be reversed by caloric restriction and exercise. Notwithstanding this assumption, the disappointing outcomes of long-term clinical studies based on this assumption show that the problem is much more complex. Obviously, recent studies render that specific neurocircuits involved in appetite regulation are etiologically integrated in the pathomechanism, suggesting obesity should be regarded as a neurobiological disease rather than the consequence of detrimental food intake habits. Moreover, apart from the physical manifestation of overeating, a growing body of evidence suggests a close relationship with psychological components comprising mood disturbances, altered reward perception and motivation, or addictive behavior. Given that current dietary and pharmacological strategies to overcome the burgeoning threat of the obesity problem are of limited efficacy, bear the risk of adverse side-effects, and in most cases are not curative, new concepts integratively focusing on the fundamental neurobiological and psychological mechanisms underlying overeating are urgently required. This new approach to develop preventive and therapeutic strategies would justify assigning obesity to the spectrum of neuropsychological diseases. Our objective is to give an overview on the current literature that argues for this view and, on the basis of this knowledge, to deduce an integrative model for the development of obesity originating from disturbed neuropsychological functioning.

Diabetes as a chronic metabolic stressor: causes, consequences and clinical complications

Diabetes mellitus is an endocrine disorder resulting from inadequate insulin release and/or reduced insulin sensitivity. The complications of diabetes are well characterized in peripheral tissues, but there is a growing appreciation that the complications of diabetes extend to the central nervous system (CNS). One of the potential neurological complications of diabetes is cognitive deficits. Interestingly, the structural, electrophysiological, neurochemical and anatomical underpinnings responsible for cognitive deficits in diabetes are strikingly similar to those observed in animals subjected to chronic stress, as well as in patients with stress-related psychiatric illnesses such as major depressive disorder. Since diabetes is a chronic metabolic stressor, this has led to the suggestion that common mechanistic mediators are responsible for neuroplasticity deficits in both diabetes and depression. Moreover, these common mechanistic mediators may be responsible for the increase in the risk of depressive illness in diabetes patients. In view of these observations, the aims of this review are (1) to describe the neuroplasticity deficits observed in diabetic rodents and patients; (2) to summarize the similarities in the clinical and preclinical studies of depression and diabetes; and (3) to highlight the diabetes-induced neuroplasticity deficits in those brain regions that have been implicated as important pathological centers in depressive illness, namely, the hippocampus, the amygdala and the prefrontal cortex.

Insulin resistance and depressive symptoms in middle-aged and elderly Chinese: findings from the Nutrition and Health of Aging Population in China Study

BACKGROUND

Depression is associated with an increased risk of incident diabetes, and insulin resistance is thought to be the underlying link between them. Nevertheless, only a few studies have explored the association between insulin resistance and depression with contradictory results, and none have been conducted in Chinese populations.

METHODS

We aimed to determine the association between insulin resistance and depressive symptoms among middle-aged and elderly Chinese using data from the Nutrition and Health of Aging Population in China Study, a population-based cross-sectional study conducted in 2005 in China. Participants included 3285 community residents aged 50-70 years. Depressive symptoms were defined as a Center for Epidemiological Studies of Depression Scale (CES-D) score of 16 or higher. Insulin resistance was calculated using the updated homeostasis model assessment (HOMA2-IR) methods.

RESULTS

Value of HOMA2-IR was significantly higher in participants with depressive symptoms (0.284 vs. 0.261, P=0.008), even after adjustment for various confounding factors in the regression model (0.311 vs. 0.291, P=0.026). Logistical regression analyses showed that participants with depressive symptoms had a higher risk of having insulin resistance (defined as in the top quartile of HOMA2-IR values, odds ratio=1.54, 95% confidence intervals=1.17-2.04).

LIMITATIONS

Due to the cross-sectional study design, causal relation remains unknown.

CONCLUSIONS

The present study found positive associations between depressive symptoms and insulin resistance among Chinese populations. Further prospective studies are needed to validate the results and find the temporal and causal relation between them.

Depression and type 2 diabetes mellitus: the multiethnic study of atherosclerosis

OBJECTIVE

To assess the cross-sectional association between depression and glucose tolerance status.

METHODS

We conducted a study of 6754 White, Black, Hispanic, and Chinese men and women aged 45 to 84 years in the Multiethnic Study of Atherosclerosis (MESA). Depression was defined as Center for Epidemiologic Studies Depression scale score of > or =16 and/or antidepressant use. Glucose tolerance status was defined as normal, impaired fasting glucose (IFG) or Type 2 diabetes mellitus (untreated and treated).

RESULTS

In the minimally adjusted model, although depression was not associated with a greater odds of IFG (odds ratio (OR) = 1.01; 95% confidence interval (CI): 0.87-1.18) or untreated diabetes (OR = 1.03; 95% CI: 0.74-1.45), it was associated with a greater odds of treated diabetes (OR = 1.57; 95% CI: 1.27-1.96). This persisted following adjustment for body mass index (OR = 1.52; 95% CI: 1.22-1.90), metabolic (OR = 1.54; 95% CI: 1.23-1.93), and inflammatory (OR=1.53; 95% CI: 1.21-1.92) factors, daily caloric intake and smoking (OR = 1.48; 95% CI: 1.16-1.88), and socioeconomic markers (OR = 1.47; 95% CI: 1.17-1.85). Among individuals with treated diabetes, median depression scores were higher in those with microalbuminuria compared with those without microalbuminuria (median = 7; interquartile range: 3-13 versus median = 6; interquartile range: 2-11; p = .046). Depression scores were not associated with homeostatic model assessment of insulin resistance among individuals without diabetes.

CONCLUSIONS

In MESA, depression was significantly associated with treated diabetes. Further studies are needed to determine the temporality of this association.

Major depressive disorder viewed as a dysfunction in astroglial bioenergetics

For many years scientists and physicians have pondered upon the apparent connection between depressive disorder and diabetes mellitus. Several epidemiologic studies confirm that diabetics have increased incidence of depression, and vice versa. In addition: depressive, non-diabetic patients have several insulin- and glucose-metabolism disturbances, probably exerting a compensatory reaction to the malfunction in the depressed brain as these disturbances are normalised in remission. After the discovery of PET-scanning, such studies have shown that patients with depressive disorder have reduced glucose metabolism in frontal parts of the brain. The present hypothesis regards the PET findings as observations of the primary pathophysiology of depression. Furthermore: two studies of post mortem samples from depressed patients show reduced numbers of astroglia. This is in accordance to the mentioned insulin disturbances, as only astroglia, not neurons, have insulin-sensitive glucose metabolism. Hence: the astroglia, not necessarily the neurons, are proposed to be the type of cells in which the disease resides. Most probably depressive disorder is a multitude of diseases, explaining the apparent multitude of symptoms, and the fact that different patients do respond to different drugs. Therefore: one can only formulate the hypothesis by mentioning a common denominator to these specific malfunctions, namely: disturbed glucose metabolism in the depressed brain. The present paper reviews several findings and proposes that attenuated cerebral glucose metabolism in frontal parts of the brain, in the astroglia, is the cause of depressive disorder.

Evaluation of pituitary function in the fatigued patient: a review of 59 cases

OBJECTIVE

The aim of this study was to review the results of dynamic pituitary testing in patients presenting with fatigue.

METHODS

We reviewed clinical histories and insulin tolerance test (ITT) results of 59 patients who presented with fatigue and other symptoms of glucocorticoid insufficiency over a 4-year period. All patients referred for ITT had an early-morning cortisol level of <400 nM and a low or normal ACTH level.

RESULTS

Peak cortisol and GH responses following insulin-induced hypoglycaemia were normal in only seven patients (12%). Median age of the remaining 52 patients was 47 years (range, 17-67 years); all but five were female. Common presenting symptoms were neuroglycopaenia (n = 47), depression (n = 37), arthralgia and myalgia (n = 28), weight gain (n = 25), weight loss (n = 9), postural dizziness (n = 15) and headaches (n = 13). Other medical history included autoimmune disease (n = 20; particularly Hashimoto's thyroiditis, Graves' disease and coeliac disease), postpartum (n = 8) and gastrointestinal (n = 2) haemorrhage and hyperprolactinaemia (n = 13). 31 subjects had peak cortisol levels of <500 nM (suggestive of ACTH deficiency; 18 of whom had levels < 400 nM) and a further six had indeterminate results (500-550 nM). The remaining 15 subjects had normal cortisol responses (median 654 nM; range, 553-1062 nM) but had low GH levels following hypoglycaemic stimulation (5.9 mU/l; 3-11.6 mU/l).

CONCLUSION

Our results suggest that patients presenting with fatigue and symptoms suggestive of hypocortisolism should be considered for screening for secondary adrenal insufficiency, particularly in the presence of autoimmune disease or a history of postpartum or gastrointestinal haemorrhage. Whether physiological glucocorticoid replacement improves symptoms in this patient group is yet to be established.

Impact of the selective serotonin reuptake inhibitor citalopram on insulin sensitivity, leptin and basal cortisol secretion in depressed and non-depressed euglycemic women of reproductive age

INTRODUCTION

Major depression in women of reproductive age may be accompanied by multiple endocrine and metabolic disturbances, which, in turn, may affect reproductive functioning. Enhanced cortisol synthesis, impaired leptin production and diminished insulin sensitivity have been reported in some depressed populations. We sought to determine whether an 8-week administration of citalopram would have an effect on these endocrine factors in a group of euglycemic depressed and non-depressed women of reproductive age.

MATERIALS AND METHODS

Fourteen depressed and 18 non-depressed women (diagnosed by structured clinical interview) aged between 18 and 45 years completed an 8-week study. All depressed women were treated with citalopram and non-depressed subjects randomized to citalopram or no treatment in an open label cohort study. An oral glucose tolerance test with insulin levels was performed at baseline and at the end of the 8-week trial. Weight, blood pressure, fasting serum cortisol, fasting serum leptin and Beck Depression Inventory were assessed at baseline, 2, 4 and 8 weeks.

RESULTS

Citalopram significantly improved depressive symptoms and Beck Depression Inventory scores in the depressed cohort. Cortisol production was higher in depressed women but did not diminish with citalopram therapy over 8 weeks. Indices of insulin sensitivity and leptin production were similar between depressed and non-depressed women and did not change despite citalopram therapy.

CONCLUSION

. Insulin sensitivity in moderately depressed women of reproductive age does not differ from that in a similar group of non-depressed women. Insulin sensitivity, cortisol secretion and leptin production do not change significantly in depressed women following an 8-week course of citalopram despite substantial improvement in depression scores.

A double-blind, placebo-controlled, exploratory trial of chromium picolinate in atypical depression: effect on carbohydrate craving

BACKGROUND

: In a small pilot trial, patients with atypical depression demonstrated significant positive therapeutic response to chromium picolinate. This finding is of interest because of the demonstrated link between depression, decreased insulin sensitivity, and subsequent diabetes and chromium picolinate's insulin enhancing effect.

METHODS

: In this double-blind, multicenter, 8-week replication study, 113 adult outpatients with atypical depression were randomized 2:1 to receive 600 mug/day of elemental chromium, as provided by chromium picolinate (CrPic), or placebo. Primary efficacy measures were the 29-item Hamilton Depression Rating Scale (HAM-D-29) and the Clinical Global Impressions Improvement Scale (CGI-I).

RESULTS

: Of the 113 randomized patients, 110 (70 CrPic, 40 placebo) constituted the intent-to-treat (ITT) population (i.e., received at least one dose of study medication and completed at least one efficacy evaluation) and 75 (50 CrPic, 25 placebo) were evaluable (i.e., took at least 80% of study drug with no significant protocol deviations). In the evaluable population, mean age was 46 years, 69% were female, 81% were Caucasian, and mean body mass index (BMI) was 29.7. There was no significant difference between the CrPic and placebo groups in both the ITT and evaluable populations on the primary efficacy measures, with both groups showing significant improvement from baseline on total HAM-D-29 scores during the course of treatment (p < 0.0001). However, in the evaluable population, the CrPic group showed significant improvements from baseline compared with the placebo group on 4 HAM-D-29 items: appetite increase, increased eating, carbohydrate craving, and diurnal variation of feelings. A supplemental analysis of data from the subset of 41 patients in the ITT population with high carbohydrate craving (26 CrPic, 15 placebo; mean BMI = 31.1) showed that the CrPic patients had significantly greater response on total HAM-D-29 scores than the placebo group (65% vs. 33%; p < 0.05) as well as significantly greater improvements on the following HAM-D-29 items: appetite increase, increased eating, carbohydrate craving, and genital symptoms (e.g., level of libido). Chromium treatment was well-tolerated.

LIMITATIONS

: The study did not include a placebo run-in period, did not require minimum duration or severity of depression, and enrolled patients with major depression, dysthymia, or depression NOS.

CONCLUSIONS

: In a population of adults with atypical depression, most of whom were overweight or obese, CrPic produced improvement on the following HAM-D-29 items: appetite increase, increased eating, carbohydrate craving, and diurnal variation of feelings. In a subpopulation of patients with high carbohydrate craving, overall HAM-D-29 scores improved significantly in patients treated with CrPic compared with placebo. The results of this study suggest that the main effect of chromium was on carbohydrate craving and appetite regulation in depressed patients and that 600 mug of elemental chromium may be beneficial for patients with atypical depression who also have severe carbohydrate craving. Further studies are needed to evaluate chromium in depressed patients specifically selected for symptoms of increased appetite and carbohydrate craving as well as to determine whether a higher dose of chromium would have an effect on mood.

Depression and glycemic control in Hispanic primary care patients with diabetes

CONTEXT

Maintaining optimal glycemic control is an important goal of therapy in patients with diabetes mellitus. Patients of Hispanic ancestry have been shown to have high rates of diabetes and poor glycemic control (PGC). Although depression is common in adults with diabetes, its relationship to glycemic control remains unclear, especially among Hispanics.

OBJECTIVE

To assess the association of depression with PGC in Hispanics.

DESIGN

Data from a cross-sectional mental health survey in primary care were crosslinked to the hospital's computerized laboratory database.

SETTING

Urban general medicine practice at a teaching hospital.

PATIENTS

Two hundred and nine patients (mean [standard deviation] age, 57.1 [10.3] years; 68% females) with recent International Classification of Diseases, Ninth Revision (ICD-9) codes for diabetes mellitus, and 1 or more hemoglobin A(1c) (HbA(1c)) tests.

MAIN OUTCOME MEASURE

Probability of PGC (HbA(1c)>or=8%).

RESULTS

Probability for PGC steadily increased with severity of depression. Thirty-nine (55.7%) of the 70 patients with major depression had HbA(1c)>or=8%, compared with 39/92 (42.4%) in the minimal to mild depression group, and 15/47 (31.9%) in the no depression group (P(trend)=.01; adjusted odds ratio, 3.27; 95% confidence interval, 1.23 to 8.64, for moderate or severe depression vs no depression). Only 29 (41.4%) of the patients with major depression received mental health treatment in the previous year.

CONCLUSIONS

In this primary care sample of Hispanic patients with diabetes, we found a significant association between increasing depression severity and PGC. Yet, less than one half of the patients with moderate or severe depression received mental health treatment in the previous year. Improving identification and treatment of depression in this high-risk population might have favorable effects on diabetic outcomes.

Depression in diabetic patients: the relationship between mood and glycemic control

PROBLEM

Evidence from prospective and cross-sectional studies demonstrates that the presence of diabetes doubles the risk of comorbid depression. This commonly overlooked comorbidity affects more than one quarter of the diabetic population, making its recognition and treatment in diabetic patients clinically relevant.

METHODS

PubMed, PsycINFO, and MEDLINE databases were searched (search words: diabetes, depression, metabolic control, hyperglycemia, hypoglycemia) for articles that evaluated outcomes, relationships, and/or management of comorbid depression and diabetes published between 1980 and 2002. This review represents a synthesis of the findings including treatment recommendations.

RESULTS

Concurrent depression is associated with a decrease in metabolic control, poor adherence to medication and diet regimens, a reduction in quality of life, and an increase in health care expenditures. In turn, poor metabolic control may exacerbate depression and diminish response to antidepressant regimens. Psychotherapy and pharmacotherapy are effective in the presence of diabetes; both cognitive behavior therapy and selective serotonin reuptake inhibitors are weight neutral and have been associated with glycemic improvement in some studies.

CONCLUSION

Depression is common in both type 1 and type 2 diabetes and has significant effects on the course and outcome of this medical illness. Conventional antidepressant management strategies are effective and the regimen should be tailored to the individual patient. Enhanced efforts toward good glycemic control may also contribute to improvements in mood and perceptions of well-being.

Depression-related hyperglycemia in type 1 diabetes: a mediational approach

OBJECTIVE

Depression is linked with hyperglycemia and with an increased risk for diabetes complications, but the mechanisms underlying these relationships have not been established. In this study, we applied mediational analysis methods to determine whether the hyperglycemic effect of depression could be mediated by poor diabetes self-care.

METHODS

Depression symptoms and diabetes self-care activity were assessed in a primary care sample of 188 patients with type 1 diabetes by using the Hopkins Symptom Checklist-90 (SCL-90) and the Summary of Diabetes Self-Care Activities (SDSCA). A composite score of self-care activity was formed from SDSCA ratings for diet amount, exercise, and glucose testing. Degree of hyperglycemia (level of glycosylated hemoglobin [HbA1c]), weight, insulin dose, and other clinical characteristics were obtained from electronic medical records. Ordinary least-squares regression was used to determine the effect of depression on HbA1c level controlling for weight and insulin dose. The SDSCA score was then added to the regression model to determine whether it attenuated the effect of depression symptoms on HbA1c level, thus providing suggestive evidence of mediation from these cross-sectional data.

RESULTS

Depression symptoms, poor diabetes self-care, and hyperglycemia were correlated with one another in univariate analyses (p <.05). Depression symptoms were associated with higher HbA1c after controlling for weight and insulin dose (parameter estimate for depression 0.53, t = 3.6, p <.001). Inclusion of SDSCA in the model minimally attenuated the effect of depression symptoms (adjusted parameter estimate for depression 0.50, t = 3.3, p = .001).

CONCLUSIONS

These findings do not support mediation of the depression-hyperglycemia relationship by diabetes self-care behavior. Other pathways, including psychophysiological mechanisms, should be investigated.

High CSF-insulin in violent suicide attempters

Several studies have investigated a connection between diabetes and major depressive disorder (MDD). Whether these associations are mediated by changes in insulin is not known. Insulin seems to play a role in violent behaviour. To further elucidate the role of insulin in MDD and violent, aggressive, or impulsive behaviour, we measured insulin in cerebrospinal fluid (CSF) in 74 patients with a recent suicide attempt. Patients were divided into those with and without MDD, and they were also subgrouped by whether the suicide attempt was considered to be violent or not. It was found that patients with a violent suicide attempt had significantly higher CSF-insulin (5.9+/-1.0 pmol/l) than those with a nonviolent attempt (5.3+/-0.7 pmol/l). In contrast, there were no significant differences in CSF-insulin between patients with MDD and patients without. Our findings support the hypothesis that CSF-insulin is involved in violent behaviour, but not connected to MDD as such.

Lipid metabolism and insulin resistance in depressed patients: significance of weight, hypercortisolism, and antidepressant treatment

Major depression increases cardiovascular risk despite lower cholesterol levels. Little is known about effects of antidepressants on metabolic risk factors. We studied lipoprotein composition, insulin sensitivity (quantitative insulin sensitivity check index), and saliva cortisol in 78 depressed patients before and after 35 days of amitriptyline or paroxetin treatment. Data were analyzed by principal component factor analyses and analysis of variance (ANOVA). At baseline, quantitative insulin sensitivity check index was inversely correlated with cortisol (r = -0.46; P = 0.005) in normal weight patients, with body mass index in overweight patients (r = -0.50; P < 0.001). In overweight patients, hypercortisolemia correlated inversely with total and low density lipoprotein cholesterol (eg, cortisol at 4:00 PM and low density lipoprotein cholesterol: r = -0.49, P = 0.002). After treatment, quantitative insulin sensitivity check index was unchanged. Triglycerides increased in responders to amitriptyline only (P < 0.05). Parameters of cholesterol metabolism improved slightly without differences between treatment groups (eg, high density lipoprotein: pre 43.5 +/- 12.0; post 47.6 +/- 13.0 mg/dL; P = 0.01; low density lipoprotein triglycerides, a measure of low density lipoprotein atherogenicity: pre 458 +/- 120; post 415 +/- 130 mg/g; P < 0,01). The inverse correlation of cortisol and cholesterol, at least in the obese subgroup, proposes a mechanism for the known association of depression with low cholesterol. As determinants of plasma lipids in major depression, we identified body mass index, insulin sensitivity, and cortisol. Although uncontrolled, our data suggest that treatment of depression exerts a mainly beneficial effect on lipid regulation.

Insulin resistance, affective disorders, and Alzheimer's disease: review and hypothesis

Affective disorders (ad) and Alzheimer's disease (AD) have been associated for almost a century, and various neurophysiologic factors have been implicated as common biologic markers. Yet, links between ad and AD still await elucidation. We propose that insulin resistance (IR) is one of the missing links between ad and AD. IR with hyperinsulinemia and subsequent impairment of glucose metabolism especially in ad patients may promote neurodegeneration and facilitate the onset of AD. According to our hypothesis, IR may persist even into ad remission in some patients. Persistent regional hypometabolism and vascular changes resulting from long-standing IR may lead to currently irreversible structural changes. Evidence in support of the hypothesis is reviewed and clinical implications suggested.

Depression in women with polycystic ovary syndrome: clinical and biochemical correlates

BACKGROUND

We assessed the prevalence of mood disturbance among women with prospectively documented polycystic ovary syndrome (PCOS).

METHODS

Thirty-two women with PCOS completed the Center for Epidemiological Studies-Depression Rating Scale (CES-D). Clinical and biochemical characteristics were assessed.

RESULTS

Sixteen women had CES-D scores indicative of depression. Depression was associated with greater insulin resistance (P=0.02) and higher body mass index (P=0.05). Women receiving oral contraceptives for the treatment of PCOS were less depressed than patients not receiving treatment (P=0.03).

LIMITATIONS

Possible selection bias, use of a screening tool alone without further diagnostic evaluation of depression, small samples size and lack of direct comparison with an age matched control group, should be considered in interpretation of these results.

CONCLUSION

Findings suggest a high prevalence of depression among women with PCOS, and an association between depression and PCOS markers.

Insulin resistance: a metabolic link between depressive disorder and atherosclerotic vascular diseases

The association of depression with insulin resistance (IR) and athersclerotic vascular diseases has been well documented. This review examines the relevance of IR as a link between depressive disorder and atherosclerotic vascular diseases. Relevant articles collected from Medline database over the period of 1966-2001 were reviewed. Studies have shown that IR is a state-dependent abnormality in depression and depression increases the risk of vascular morbidity and mortality. Given that IR is a central component of cardiovascular risk factors, depression-related IR might play a role in the development and progression of coronary and cerebral atherosclerosis in chronic-resistant depression. Further, IR may contribute to the pathophysiology of depressive disorder. In conclusion IR could account for the linkage between depression and atherosclerotic vascular diseases. More studies are needed to examine the importance of improving insulin sensitivity in the treatment of chronic-resistant depression and prevention of depression-related vascular morbidity and mortality.

Treatment of depression in diabetes: impact on mood and medical outcome

Depression is prevalent as a co-morbid condition in diabetes. The efficacy of depression treatment with either pharmacological agents or psychotherapy has been demonstrated in the few available controlled trials. Depression has been associated with poor glycemic control and with accelerated rates of coronary heart disease in diabetic patients. Reported depression treatment trials demonstrate benefits of depression remission on glycemic control as well as mood and the potential for improvement in the course and outcome of diabetes. Because adverse effects of pharmacological agents on glycemic control have been observed, optimal therapies that improve both depression and measures of diabetes are still being sought. This review critically examines the efficacy of depression treatment in diabetes patients, the effects of depression treatment on the medical condition, and methodological issues important in the performance of treatment trials in the patient population.

Cushing’s disease and melancholia

Striking similarities exist in the endocrinology of Cushing's disease and melancholic depression.Laboratory abnormalities, which have been found in both, include raised urinary,plasma and salivary cortisol, non-suppression of cortisol in the dexamethasone suppression test and adrenocorticotrophin (ACTH) hypersecretion. The hypercortisolism can be so severe in melancholic depression that it is difficult to distinguish from Cushing's disease and has been described as a "pseudo-Cushing's" state. Cerebrospinal fluid corticotrophin-releasing hormone (CRH) levels have been found to be lower in patients with Cushing's disease than in depressed subjects. Dynamic endocrine tests may help to distinguish between the two disorders.An exaggerated response to synacthen has been found in both but a reduced ACTH response to CRH occurs in depression, unlike those with Cushing's disease who show ACTH hyper-responsiveness. Other tests, which may help to distinguish between the two disorders,include the dexamethasone-CRH test, the naloxone test, the insulin-induced hypoglycemia test and the desmopressin stimulation test. Similarities in psychiatric symptoms have been recognised for many years. More recently, the physical complications of melancholic depression have been noted. These include osteoporosis, an increased risk of death from cardiovascular disease, hypertension, a redistribution of fat to intra abdominal sites and insulin resistance. Cushing's disease shares these physical complications and we propose that the common underlying factor is excessive plasma glucocorticoids. The increasing recognition of the physical complications and the increased morbidity and mortality in those who suffer from depression underscores the necessity for early detection and treatment of this illness and screening for undetected physical complications.

Alpha lipoic acid: a novel treatment for depression

Insulin resistance has been associated with people diagnosed with depression. Conversely, it has also been documented that diabetics have an increased risk of depression. Evidence suggests that insulin activity plays a role in serotonergic activity by increasing the influx of tryptophan into the brain. This increased influx of tryptophan has been shown to result in an increase in serotonin synthesis. In accordance with the serotonin theory of depression, it may be possible to treat depression by increasing insulin activity. The antioxidant alpha lipoic acid has been shown to increase insulin sensitivity and is used to treat people with diabetes. Therefore, the nutrient alpha lipoic acid should be clinically tested as an adjunct treatment for depression.

The relationship between central serotonergic activity and insulin sensitivity in healthy volunteers

In order to determine whether central serotonin (5-HT) activity is related to sensitivity of insulin receptors, 19 healthy volunteers with normal basal glycemia and HbAlc were studied. The relationship between prolactin response to D-fenfluramine (delta PRL) in a challenge test and metabolic clearance rates (MCR) of glucose during the hyperinsulinemic-euglycemic clamp technique was evaluated. delta PRL had been chosen as a correlate of central 5-HT activity. Two levels of insulin concentration of approximately 70 mU/l (MCRsubmax) and 2000 mU/l (MCRmax) were used in a clamp, each for a duration of 120 min. A negative correlation was found between delta PRL and MCRsubmax (r = -0.55, P < 0.02) and between delta PRL and MCRmax (r = -0.51, P < 0.03). We did not find any correlation between the prolactin response to D-fenfluramine and body weight, body mass index (BMI) or waist and hip circumference (WHR). The data support the hypothesis of a close connection between 5-HT activity in the brain and peripheral sensitivity to insulin. The possible physiological mechanisms of this connection are discussed.

Symptoms at the menopausal and premenopausal years: their relationship with insulin, glucose, cortisol, FSH, prolactin, obesity and attitudes towards sexuality

The symptoms of 81 premenopausal and 70 menopausal women were studied to determine the association with obesity, attitudes towards sexuality (ATS), and diverse hormone values: fasting and postprandial glucose (FG, PG) and insulin (FI, PI), cortisol, prolactin, follicle-stimulating hormone (FSH). The mean age of the women studied was 49.1 years. The frequency of symptoms was 35.4% for depression, 34.3% for nonspecific symptoms of depression (NSSD), 38.6% for empty nest syndrome (ENS), and 42.3% for anxiety. NSSD, ENS, FSH and cortisol levels all possessed higher values at late-menopausal stage. A multiple regression analysis revealed the following results; NSSD was associated to ATS (negative); sleep alterations were correlated to prolactin, FSH, PI/PG, FI/FG and waist/hip ratio; FSH was associated with both a decreased sexual interest and depression. In the study of hormone levels it was found that cortisol, insulin and FI/FG were associated with ATS; PI, cortisol, FI/FG and PI/PG were associated with body mass index (BMI) and FSH; prolactin and FI/FG were associated with age. We concluded that: (1) data indicative of insulin resistance correlated to both depression and sleep alterations; (2) overweight is related to NSSD, sleep alterations, and hormonal changes.

Enhancing central and peripheral insulin activity as a strategy for the treatment of endogenous depression--an adjuvant role for chromium picolinate?

Depression is often associated with insulin resistance, owing to cortisol overproduction; conversely, many studies suggest that diabetics are at increased risk for depression. Recent evidence indicates that insulin is transported through the blood-brain barrier and influences brain function via widely distributed insulin receptors on neurons. These receptors are particularly dense on catecholaminergic synaptic terminals, and, while effects are variable dependent on brain region, several studies indicate that insulin promotes central catecholaminergic activity, perhaps by inhibiting synaptic re-uptake of norepinephrine. Additionally, it is well known that insulin enhances serotonergic activity in increasing blood-brain barrier transport of tryptophan. Since impaired monoaminergic activity in key brain pathways is believed to play an etiological role in depression, techniques which promote effective insulin activity, both centrally and peripherally, may be therapeutically beneficial in this disorder. This may rationalize anecdotal reports of improved mood in clinical depressives and diabetics receiving the insulin-sensitizing nutrient chromium picolinate. This nutrient, perhaps in conjunction with other insulin-sensitizing measures such as low-fat diet and aerobic exercise training (already shown to be beneficial in depression), should be tested as an adjuvant for the treatment and secondary prevention of depression.

Weak magnetic fields antagonize the effects of melatonin on blood glucose levels in Parkinson's disease

Treatment with picoTesla magnetic fields recently has been reported to attenuate symptoms of Parkinson's disease (PD). The mechanisms by which weak magnetic fields ameliorate Parkinsonian symptoms are unknown. There is evidence that the pineal gland is a "magnetosensor" in the brain since in experimental animals exposure to external magnetic fields alters the firing rate of pineal cells and induces inhibition of melatonin secretion. Hence, the clinical effects of weak magnetic fields in PD likewise may involve the mediation of the pineal gland. Animal data indicate that the pineal gland is involved in the regulation of glucose metabolism and that exogenous administration of melatonin induces an hyperglycemic effect. To investigate the hypothesis that the pineal gland mediates the therapeutic properties of weak magnetic fields in PD, I studied the effects of orally administered melatonin (3.0 mg) followed by a 6 minute application of low intensity external weak magnetic fields (7.5 picoTesla) on blood glucose levels in two Parkinsonian patients. In both patients melatonin challenge produced a moderate hyperglycemic effect which was reversed by subsequent stimulation with weak magnetic fields. These findings support the hypothesis that weak magnetic fields inhibit melatonin secretion and that the antiParkinsonian properties of weak magnetic fields are mediated partially via the inhibition of melatonin secretion. Furthermore, these data suggest that melatonin receptor antagonists could be beneficial as an adjunctive treatment in PD and highlight the importance of the pineal-hypothalamic axis in the pathophysiology of the disease as well as in the mechanisms of action of antiParkinsonian drugs.

Blunted ACTH response to hypoglycemic stress in depressed patients but not in patients with schizophrenia

In this study, 7 hospitalized patients with major depression (MD), 5 hospitalized patients with schizophrenia (S), and 13 control subjects (C) were administered 0.15 units/kg of regular insulin at 1600 h by intravenous bolus infusion. ACTH, cortisol, and glucose levels were measured intermittently for 2h following infusion. Baseline ACTH, cortisol and glucose levels were similar in Cs, MDs, and Ss. The mean glucose nadir was equivalent for Cs, patients with MD, and patients with S. Patients with MD had a blunted ACTH response (F = 3.28; df = 12,126; p = .0004) and cortisol response (F = 4.20; df = 12,132; p = .0001) to hypoglycemia when compared to Cs and patients with S. Carroll Depression Rating Scale scores in patients with S (23 +/- 10) were similar to patients with MD (30 +/- 8) and significantly higher than in controls (1 +/- 2) (F = 55.2; df = 2.22; p = .0001). These findings suggest that patients with MD show different ACTH and cortisol responses to hypoglycemic stress which are not explained by negative feedback of baseline ACTH or cortisol, glucose nadir, or the number of depressive symptoms per se.

Hypothalamic-pituitary-adrenal axis dysregulation among diabetic outpatients

We compared insulin-requiring diabetic outpatients (n = 49) with normal controls (n = 42) for indices of hypothalamic-pituitary-adrenal (HPA) axis activity. Diabetic patients showed significantly elevated 9 a.m. plasma levels of cortisol as well as significantly elevated plasma levels of cortisol and adrenocorticotropic hormone (ACTH) at both 4 p.m. before and 4 p.m. after dexamethasone. Also, there was a significant correlation between postdexamethasone plasma levels of ACTH and duration of diabetes. These results suggest that HPA-axis dysregulation is found among diabetic outpatients. The possible psychiatric implications are discussed.

Hyperinsulinemia; a mediator of decreased food intake and weight loss in anorexia nervosa and major depression

Decreased food intake and weight loss are seen in eating and depressive disorders. No satisfactory pathophysiological mechanisms have been proposed to explain those findings. While it should be kept in mind that the etiology of those diseases is still unclear, it seems reasonable to propose that the maintenance of anorectic behavior in the eating disorders as well as the decreased food intake of major depression, leading to continued weight loss seen in both conditions, are either caused or mediated by insulin in levels which are elevated but insufficient to cause hypoglycemia. A brief review is made of the role of insulin in satiety and in the control of body weight, and of the newly available techniques to accurately quantify secretion, hepatic extraction, and post-hepatic delivery rates of insulin. Neural, metabolic, and endocrine stimuli affect insulin secretion. The hypothesis is therefore compatible with several etiologic factors leading to hyperinsulinemia in anorexia nervosa and major depression, and resulting in decreased food intake and weight loss.

Serotonergic function in diabetic rats: psychotherapeutic implications

Extracellular serotonin in striatum was studied in untreated streptozotocin-induced diabetic rats and in untreated nondiabetic rats that served as age-, food-, and sex-matched controls. Extracellular serotonin was studied under anesthesia in vivo and dynamically with voltammetry. The results showed that an early and significant increase in extracellular serotonin occurred in striatum in the untreated acutely (3 days) diabetic rat. In untreated long-term (3-7 weeks) diabetic rats, however, the increase in serotonin in extracellular fluid in striatum decreased and returned to normal. The findings show a change in serotonergic function in acutely diabetic rats. The serotonergic alteration may have psychotherapeutic implications.

Insulin-induced hypoglycaemic response and release of growth hormone in depressed patients and healthy controls

As part of the Collaborative Study of the Psychobiology of Depression, we have examined the pretreatment growth hormone response (delta GH) to insulin (0.1 U/kg) and the magnitude of the hypoglycaemic response in a large number of well-defined depressed patients (N = 132) and healthy controls (N = 80). After applying rigorous exclusion criteria, data were analysed from 93 patients and 66 controls for blood glucose response and from 56 patients and 52 controls for delta GH. Depressed patients, either unipolar or bipolar, showed less of a fall in glucose than controls. A weak association was found between the magnitude of the fall in glucose and the severity of depression. No significant differences were found in values for delta GH between the unipolar or bipolar depressed patients and controls either for males, pre-menopausal or post-menopausal females, or the total female group. These data do not support previous claims of a lowered delta GH response to insulin in depressed patients. However, the resistance to hypoglycaemia seen in the depressed patients is consistent with previous reports.

Chronic imipramine treatment and weight gain

A study of weight change in subjects treated with imipramine was performed on recurrent depressive outpatients. The patients (n = 52) were treated with imipramine (200-250 mg/day) and psychotherapy for 16 weeks. Each individual was weighed upon entry to the study (drug-free) and then weekly thereafter for 16 weeks. Of the 44 women (85%) and 8 men (15%) in the study, 60% of the total group had a weight gain or loss less than 5 pounds (mean = 1.1 pounds) over this time. A weight gain of 6-10 pounds was observed in 19% of subjects, while 9% of the group gained 11-15 pounds. Only 6% (3 subjects) gained more than 15 pounds. Three subjects (6%) lost 6-10 pounds. No correlations were observed between a change in weight and the subject's age, sex, prior weight, or response to medication.

Neuroendocrine changes in depression

Biological research in depression has concentrated on 'endogenous' depressions and over the past 30 years has been guided by the amine theory. Neuroendocrine abnormalities in depression have been reported for over 20 years and include changes in the hypothalamic-pituitary-adrenal and thyroid axes, in growth hormone and prolactin secretion. As neurotransmitters regulate neuroendocrine secretion, inter-relationships between neurochemical and neuroendocrine abnormalities may provide a window for understanding the pathophysiology of depression. The availability of these biological markers for depression opens new possibilities for research in psychiatric diagnosis and for management.

[Causal analytic studies on demonstration of neuroendocrine parameters in combined hypoglycemia test in depressive subgroups]

With the help of an analytical path structure model (causal analysis) the aim of the study was to elucidate further, in female patients with various depressive disorders, some correlations of causal interdependencies between changes both in basal secretion of anterior pituitary hormones and in their responses to the (combined) insulin tolerance test (ITT) with extraneous factors--such as age, deviation from ideal body weight (in percentage), severity of depression and score in the Newcastle Scale (NCS)--that may influence these abnormalities. In various depressive subgroups the strength of influence and the different importance of deviation from ideal body weight and basal growth hormone (GH) concentration (as exclusion criteria) for their neuroendocrine reactivity in the combined ITT was shown. The hypothesis that cortisol hypersecretion may be the primary disturbance and the other possible neuroendocrine changes such as blunted GH, cortisol and TSH responses to stimuli in some depressive patients all may be secondary to the (elevated) cortisol level could not be corroborated. The endogenous mono- and bipolar subtypes of major depressive disorders showed intimate connections between the various neuroendocrine functional systems and the above mentioned extraneous factors resulting in a narrowed variability and a stronger coupling in the reactivity of these hormonal functional systems, a condition which can be seen as analogous to experimental results at the psychophysiological level in these nuclear groups of depressed patients, whose psychopathological state is also characterized by similar limitations in their "degree of freedom" (Heimann).