Fluoxetine improves bone microarchitecture and mechanical properties in rodents undergoing chronic mild stress - an animal model of depression.

Depression is one of the most prevalent mental disorders associated with reductions in bone mineral density and increased fracture risk. Fluoxetine is a highly prescribed selective serotonin reuptake inhibitor (SSRI) in the treatment of depression and is reported to be a risk factor for fractures. The present study examined the effect of fluoxetine on bone microarchitecture and the mechanical properties under chronic mild stress (CMS), a rodent model of depression. Thirty-one 6-9 week-old rats were allocated to 4 groups: 1) CMS + fluoxetine group (n = 10), 2) fluoxetine-only group (n = 5), 3) CMS + placebo group (n = 10) and 4) control group (no CMS and treatment) (n = 6). After 16 weeks, bone microarchitecture of the distal femur was analyzed by µCT. Mechanical properties were assessed by the three-point bending test, and antidepressant efficacy was determined by sucrose preference and forced swimming tests. Significant correlations were found between volume of sucrose intake and bone volume/tissue volume (BV/TV) (p = 0.019) and elastic absorption energy (p = 0.001) in the fluoxetine only group. The fluoxetine-only group showed significantly higher in the second moment of area in y-direction (p = 0.0298), horizontal outer diameter (mm) (p = 0.0488) and average midshaft thickness (mm) (p = 0.00047) than control group. Comparing with the control group, there was a significant reduction in trabecular number (Tb.N) in the CMS + fluoxetine group (p = 0.026) but not the fluoxetine-only group (p > 0.05). Significant increases in trabecular separation were observed in the metaphysis of CMS + placebo (p = 0.003) and CMS + fluoxetine (p = 0.004) groups when compared to the control group but not in the fluoxetine-only group (p > 0.05). During the three-point bending test, the fluoxetine-only group demonstrated significantly higher structural strength than controls (p = 0.04). Micro computed tomography (µCT) slices showed loss of trabecular bone in the metaphysis region of the CMS + fluoxetine and CMS + placebo groups but not the fluoxetine-only and control groups. In an animal model of depression, the adverse effect on the bone microarchitecture was caused by CMS but not by fluoxetine. Without exposure to CMS, fluoxetine significantly increased the cross-sectional area, trabecular bone area, structural strength and osteoblasts / bone area as compared to control condition.

Premenopausal Singaporean Women Suffering from Major Depressive Disorder Treated with Selective Serotonin Reuptake Inhibitors Had Similar Bone Mineral Density as Compared with Healthy Controls.

The association between selective serotonin reuptake inhibitor (SSRI) treatment and lower bone mineral density (BMD) remains controversial, and further research is required. This study aimed to compare the BMD, levels of bone formation and bone metabolism markers in medicated premenopausal Singaporean women with major depressive disorder (MDD) and matched healthy controls. We examined 45 women with MDD who received SSRI treatment (mean age: 37.64 ± 7) and 45 healthy controls (mean age: 38.1 ± 9.2). BMD at the lumbar spine, total hip and femoral neck were measured using dual-energy X-ray absorptiometry. We also measured bone formation markers, procollagen type 1 N-terminal propeptide (P1NP) and bone metabolism markers, osteoprotegerin (OPG) and receptor activator of nuclear factor-kappa-Β ligand (RANKL). There were no significant differences in the mean BMD in the lumbar spine (healthy controls: 1.04 ± 0.173 vs. MDD patients: 1.024 ± 0.145, p = 0.617, left hip (healthy controls: 0.823 ± 0.117 vs. MDD patients: 0.861 ± 0.146, p = 0.181) and right hip (healthy controls: 0.843 ± 0.117 vs. MDD patients: 0.85 ± 0.135, p = 0.784) between healthy controls and medicated patients with MDD. There were no significant differences in median P1NP (healthy controls: 35.9 vs. MDD patients: 37.3, p = 0.635), OPG (healthy controls: 2.6 vs. MDD patients: 2.7, p = 0.545), RANKL (healthy controls: 23.4 vs. MDD patients: 2178.93, p = 0.279) and RANKL/OPG ratio (healthy controls: 4.1 vs. MDD patients: 741.4, p = 0.279) between healthy controls and medicated patients with MDD. Chronic SSRI treatment might not be associated with low BMD in premenopausal Singaporean women who suffered from MDD. This finding may help female patients with MDD make an informed decision when considering the risks and benefits of SSRI treatment.

Chronic administration of fluoxetine and pro-inflammatory cytokine change in a rat model of depression.

This study evaluated the chronic effects of fluoxetine, a commonly prescribed SSRI antidepressant, on the peripheral and central levels of inflammatory cytokines including IL-1ß, IL-6, TNF-α and IL-17 over a 4-interval in a rat model of chronic mild stress (CMS) which resembles the human experience of depression. Twenty-four Sprague-Dawley rats were randomly assigned to CMS+vehicle (n = 9), CMS+fluoxetine (n = 9) and the control (n = 6) groups. Sucrose preference and forced swim tests were performed to assess behavioral change. Blood samples were collected on day 0, 60, 90 and 120 for measurement of cytokine levels in plasma. On day 120, the brain was harvested and central level of cytokines was tested using Luminex. Four months of fluoxetine treatment resulted in changes in the sucrose preference and immobility time measurements, commensurate with antidepressant effects. The CMS+vehicle group exhibited elevated plasma levels of IL-1ß, IL-17, and TNF-α on day 60 or 120. Rats treated with fluoxetine demonstrated lower IL-1ß in plasma and brain after 90 and 120-day treatment respectively (p<0.05). There was a trend of reduction of IL-6 and TNF-α concentration. This study revealed the potential therapeutic effects of fluoxetine by reducing central and peripheral levels of IL-1ß in the alleviation of depressive symptoms.

The effect of severity of depressive disorder on economic burden in a university hospital in Singapore.

BACKGROUND: Depressive disorder is treatable but costly, thus influencing quality of life of people. AIM: Determine direct and indirect costs incurred by depressive disorder in Singapore. METHODS: A 1-year prospective naturalistic study was conducted in a university mood disorder center between 2007 and 2008. Patients with primary International Classification of Disease-10 diagnosis of depressive disorder were recruited. Disease costs between mild, moderate and severe depression, and cost predictors were analyzed and determined. RESULTS: Forty nine patients completed the study. Mean annual total costs per patient were US$7638. Indirect costs (81%) dominated the total costs. Approximately 50% of indirect costs were associated with loss of productivity and unemployment. Higher education level, higher mean Hamilton Rating Scale for Depression score and number of suicide attempts were independent variables associated with increased direct costs while mean Hamilton Rating Scale for Depression scale score was an independent variable for indirect costs. CONCLUSION: Medical cost saving strategies should focus on indirect costs.

Clinical and psychosocial factors associated with depression and anxiety in Singaporean patients with rheumatoid arthritis.

AIM: To assess the frequency of, and factors associated with, depression and anxiety in Singaporean patients with rheumatoid arthritis (RA). METHOD: One hundred RA patients were recruited in a cross-sectional study. Socio-demographics, severity of anxiety and depression, disease activity, levels of serological markers and health-related quality of life were analyzed. RESULTS: Twenty-six percent presented with anxiety, 15% with depression and 11% with both. Univariate regression showed that age (P = 0.039), Disease Activity Scale (DAS-28) (P < 0.001), number of medications (P < 0.001) and rheumatoid factor (RF) (P < 0.001) were positively associated with severity of depression, while income (P = 0.001), education (P = 0.029), self-perceived social support (P = 0.007), Short form 12 (SF-12) physical health (P < 0.001) and SF-12 mental health (P < 0.001) were negatively associated with severity of depression. After adjustment for confounding factors in multivariate regression, income (ß = -0.347, P = 0.018), RF (ß = 0.304, P = 0.043) and SF-12 mental health (ß = -0.501 P = 0.001) remained significantly associated with depression. Univariate regression showed that DAS-28 (P = 0.009), number of medications (P = 0.004) and RF (P = 0.043) were positively associated with anxiety, while income (P = 0.022), self-perceived social support (P = 0.04), SF-12 physical health (P < 0.001) and SF-12 mental health (P < 0.001) were negatively associated with anxiety. After adjustment for confounding factors, no factors remained significantly associated with anxiety. CONCLUSION: Low income, high levels of RF and poor mental health were associated with depression in RA. Our findings may help to formulate depression screening strategies. Further research is required to identify the role of RF in depression.

Research on psychoneuroimmunology: does stress influence immunity and cause coronary artery disease?

This review addresses the importance of psychoneuroimmunology (PNI) studies in understanding the role of acute and chronic psychological stressors on the immune system and development of coronary artery disease (CAD). Firstly, it illustrates how psychological stressors change endothelial function and lead to chemotaxis. Secondly, acute psychological stressors lead to leukocytosis, increased natural killer cell cytotoxicity and reduced proliferative response to mitogens while chronic psychological stressors may lead to adverse health effects. This will result in changes in cardiovascular function and development of CAD. Thirdly, acute and chronic psychological stressors will increase haemostatic factors and acute phase proteins, possibly leading to thrombus formation and myocardial infarction. The evidence for the effects of acute and chronic psychological stress on the onset and progression of CAD is consistent and convincing. This paper also highlights potential research areas and implications of early detection of immunological changes and cardiovascular risk in people under high psychological stress.