Immunological biomarkers associated with brain structure and executive function in late-life depression: exploratory pilot study

OBJECTIVE

Several immunological biomarkers are altered in late-life major depressive disorder (LLD). Immunological alterations could contribute to LLD's consequences, but little is known about the relations between specific immunological biomarkers and brain health in LLD. We performed an exploratory pilot study to identify, from several candidates, the specific immunological biomarkers related to important aspects of brain health that are altered in LLD (brain structure and executive function).

METHODS

Adults (n = 31) were at least 60 years old and had major depressive disorder. A multiplex immunoassay assessed 13 immunological biomarkers, and we examined their associations with structural MRI (grey matter volume and white matter hyperintensity volume (WMH)) and executive function (Color-Word Interference and Trail-Making tests) measures.

RESULTS

Vascular endothelial growth factor (VEGF) and the chemokine eotaxin had significant negative associations with grey matter volume (VEGF: n = 31, r = -0.65; eotaxin: n = 29, r = -0.44). Tumor necrosis factor alpha (TNF-α) had a significant positive relationship with WMHs (n = 30, r = 0.52); interferon-γ (IFN-γ) and macrophage inflammatory protein-1α (MIP-1α) were also significantly associated with WMHs (IFN-γ: n = 31, r = 0.48; MIP-1α: n = 29, r = 0.45). Only eotaxin was associated with executive function (set-shifting performance as measured with the Trail-making test: n = 33, r = -0.43).

CONCLUSIONS

Immunological markers are associated with brain structure in LLD. We found the immunological correlates of grey and white matter differ. Prospective studies are needed to evaluate whether these immunological correlates of brain health increase the risk of LLD's consequences. Eotaxin, which correlated with both grey matter volume and set-shifting performance, may be particularly relevant to neurodegeneration and cognition in LLD. Copyright © 2016 John Wiley & Sons, Ltd.

Enhanced Molecular Aging in Late-Life Depression: the Senescent-Associated Secretory Phenotype

OBJECTIVE

This study aims to investigate whether a systemic molecular pattern associated with aging (senescent-associated secretory phenotype [SASP]) is elevated in adults with late-life depression (LLD), compared with never-depressed elderly comparison participants.

DESIGN

Cross-sectional study.

PARTICIPANTS

We included 111 older adults (80 with LLD and 31 comparison participants) in this study.

MEASUREMENT

A panel of 22 SASP-related proteins was extracted from a previous multiplex protein panel performed in these participants. We conducted a principal component analysis to create the SASP index based on individual weights of each of protein.

RESULTS

Participants with LLD showed a significantly increased SASP index compared with comparison participants, after controlling for age, depressive symptoms, medical comorbidity (CIRS-G) scores, sex, and cognitive performance (F(1,98) = 7.3, p = 0.008). Correlation analyses revealed that the SASP index was positively correlated with age (r = 0.2, p = 0.03) and CIRS score (r = 0.27, p = 0.005), and negatively correlated with information processing speed (r = -0.34, p = 0.001), executive function (r = -0.27, p = 0.004) and global cognitive performance (r = -0.28, p = 0.007).

CONCLUSIONS

To the best of our knowledge, this is the first study to show that a set of proteins (i.e., SASP index) primarily associated with cellular aging is abnormally regulated and elevated in LLD. These results suggest that individuals with LLD display enhanced aging-related molecular patterns that are associated with higher medical comorbidity and worse cognitive function. Finally, we provide a set of proteins that can serve as potential therapeutic targets and biomarkers to monitor the effects of therapeutic or preventative interventions in LLD.

Circulating biosignatures of late-life depression (LLD): Towards a comprehensive, data-driven approach to understanding LLD pathophysiology

There is scarce information about the pathophysiological processes underlying Late-Life Depression (LLD). We aimed to determine the neurobiological abnormalities related to LLD through a multi-modal biomarker approach combining a large, unbiased peripheral proteomic panel and structural brain imaging. We examined data from 44 LLD and 31 control participants. Plasma proteomic analysis was performed using a multiplex immunoassay. We evaluated the differential protein expression between groups with random intercept models. We carried out enrichment pathway analyses (EPA) to uncover biological pathways and processes related to LLD. Machine learning analysis was applied to the combined dataset to determine the accuracy with which specific proteins could correctly discriminate LLD versus control participants. Sixty-one proteins were differentially expressed in LLD (p < 0.05 and FDR < 0.01). EPA showed that these proteins were related to abnormal immune-inflammatory control, cell survival and proliferation, proteostasis control, lipid metabolism, intracellular signaling. Machine learning analysis showed that a panel of three proteins (C-peptide, FABP-liver, ApoA-IV) discriminated LLD and control participants with 100% accuracy. The plasma proteomic profile in LLD revealed dysregulation in biological processes essential to the maintenance of homeostasis at cellular and systemic levels. These abnormalities increase brain and systemic allostatic load leading to the downstream negative outcomes of LLD, including increased risk of medical comorbidities and dementia. The peripheral biosignature of LLD has predictive power and may suggest novel putative therapeutic targets for prevention, treatment, and neuroprotection in LLD.

Combining moderators to identify clinical profiles of patients who will, and will not, benefit from aripiprazole augmentation for treatment resistant late-life major depressive disorder

Personalizing treatment for late-life depression requires identifying and integrating information from multiple factors that influence treatment efficacy (moderators). We performed exploratory moderator analyses using data from a multi-site, randomized, placebo-controlled, double-blind trial of aripiprazole augmentation. Patients (n = 159) aged ≥60 years had major depressive disorder that failed to remit with venlafaxine monotherapy. We examined effect sizes of 39 potential moderators of aripiprazole (vs. placebo) augmentation efficacy using the outcome of percentage reduction in depressive symptom after 12 weeks. We then incorporated information from the individually relevant variables in combined moderators. A larger aripiprazole treatment effect was related to: white race, better physical function, better performance on Trail-Making, attention, immediate, and delayed memory tests, greater psychomotor agitation and suicidality symptoms, and a history of adequate antidepressant pharmacotherapy. A smaller aripiprazole treatment effect was observed in patients with: more pain and more work/activity impairment and libido symptoms. Combining information from race and Trail-Making test performance (base combined moderator (Mb*)) produced a larger effect size (Spearman effect size = 0.29 (95% confidence interval (CI): 0.15, 0.42)) than any individual moderator. Adding other individually relevant moderators in the full combined moderator (Mf*) further improved effect size (Spearman effect size = 0.39 (95% CI: 0.25, 0.52)) and identified a sub-group benefiting more from placebo plus continuation venlafaxine monotherapy than adjunctive aripiprazole. Combining moderators can help clinicians personalize depression treatment. We found the majority of our patients benefited from adjunctive aripiprazole, but a smaller subgroup that is identifiable using clinical measures appeared to benefit more from continuation venlafaxine plus placebo.

Predictors and Moderators of Remission With Aripiprazole Augmentation in Treatment-Resistant Late-Life Depression: An Analysis of the IRL-GRey Randomized Clinical Trial

IMPORTANCE

Safe, efficacious, second-line pharmacological treatment options exist for the large portion of older adults with major depressive disorder who do not respond to first-line pharmacotherapy. However, limited evidence exists to aid clinical decision making regarding which patients will benefit from which second-line treatments.

OBJECTIVE

To test the moderating role of pretreatment executive function, severity of anxiety, and severity of medical comorbidity in remission of treatment-resistant late-life depression after aripiprazole augmentation.

DESIGN, SETTING, AND PARTICIPANTS

As follow-up to a 12-week randomized clinical trial of aripiprazole augmentation for first-line treatment-resistant late-life depression (Incomplete Response in Late-Life Depression: Getting to Remission [IRL-GRey]), we evaluated the effects of the following potential moderators and their interactions with treatment: baseline assessments of executive function (set shifting measured by the Trail Making Test) and response inhibition control (measured by a Color-Word Interference task), anxiety symptoms, and medical comorbidity. Analyses were conducted in May and June 2015.

INTERVENTIONS

Aripiprazole or placebo tablets were started at 2 mg daily and titrated as tolerated, to a maximal dose of 15 mg daily.

MAIN OUTCOMES AND MEASURES

Remission of treatment-resistant late-life depression (defined as a Montgomery-Åsberg Depression Rating Scale score of ≤10 at both of the last 2 consecutive visits).

RESULTS

Of 181 trial participants (103 female [56.9%]) who were 60 years of age or older and whose major depression had failed to remit with venlafaxine hydrochloride monotherapy, 91 received aripiprazole and 90 received placebo. Remission occurred in 40 (43%) who received aripiprazole and 26 (29%) who received placebo. Baseline set shifting moderated the efficacy of aripiprazole augmentation (odds ratio [OR], 1.66 [95% CI, 1.05-2.62]; P = .03 for interaction with treatment). Among participants with a Trail Making Test scaled score of 7 or higher, the odds of remission were significantly higher with aripiprazole than with placebo (53% vs 28%; number needed to treat, 4; OR, 4.11 [95% CI, 1.83-9.20]). Among participants with a Trail Making Test scaled score of less than 7, aripiprazole and placebo were equally efficacious (OR, 0.64 [95% CI, 0.15-2.80]). Greater severity of anxiety at baseline predicted a lower remission rate but did not moderate aripiprazole efficacy; each standard deviation greater anxiety severity was associated with 50% reduced odds of remission in both aripiprazole and placebo arms. Medical comorbidity and Color-Word Interference test performance were neither general predictors nor treatment-moderating factors.

CONCLUSIONS AND RELEVANCE

Set-shifting performance indicates which older adults with treatment-resistant depression may respond favorably to augmentation with aripiprazole and thus may help to personalize treatment.

TRIAL REGISTRATION

clinicaltrials.gov Identifier: NCT00892047.

Inflammatory markers among adolescents and young adults with bipolar spectrum disorders

OBJECTIVE

Despite burgeoning literature in middle-aged adults, little is known regarding proinflammatory markers (PIMs) among adolescents and young adults with bipolar disorder. Similarly, few prior studies have considered potential confounds when examining the association between PIMs and bipolar disorder characteristics. We therefore retrospectively examined these topics in the Course and Outcome of Bipolar Youth (COBY) study.

METHOD

Subjects were 123 adolescents and young adults (mean [SD] = 20.4 ± 3.8 years; range, 13.4-28.3 years) in COBY, enrolled between October 2000 and July 2006. DSM-IV diagnoses were determined using the Schedule for Affective Disorders and Schizophrenia for School-Age Children (K-SADS). Clinical characteristics during the preceding 6 months, including mood, comorbidity, and treatment, were evaluated using the Longitudinal Interval Follow-Up Evaluation (LIFE). Serum levels of interleukin (IL)-6, tumor necrosis factor (TNF)-α, and high-sensitivity C-reactive protein (hsCRP) were assayed. Primary analyses examined the association of PIMs with bipolar disorder characteristics during the preceding 6 months.

RESULTS

Several lifetime clinical characteristics were significantly associated with PIMs in multivariable analyses, including longer illness duration (P = .005 for IL-6; P = .0004 for hsCRP), suicide attempts (P = .01 for TNF-α), family history of suicide attempts or completion (P = .01 for hsCRP), self-injurious behavior (P =.005 for TNF-α), substance use disorder (SUD) (P < .0001 for hsCRP), and family history of SUD (P = .02 for TNF-α; P = .01 for IL-6). The following bipolar disorder characteristics during the preceding 6 months remained significantly associated with PIMs in multivariable analyses that controlled for differences in comorbidity and treatment: for TNF-α, percentage of weeks with psychosis (χ(2) = 5.7, P =.02); for IL-6, percentage of weeks with subthreshold mood symptoms (χ(2)= 8.3, P = .004) and any suicide attempt (χ(2) = 6.1, P = .01); for hsCRP, maximum severity of depressive symptoms (χ(2) = 8.3, P =.004).

CONCLUSION

Proinflammatory markers may be relevant to bipolar disorder characteristics as well as other clinical characteristics among adolescents and young adults with bipolar disorder. Traction toward validating PIMs as clinically relevant biomarkers in bipolar disorder will require repeated measures of PIMs and incorporation of relevant covariates.

Effect of 2 psychotherapies on depression and disease activity in pediatric Crohn's disease

BACKGROUND

Crohn's disease (CD) is associated with depression. It is unclear if psychosocial interventions offer benefit for depressive symptoms during active CD. In this secondary analysis of a larger study of treating depression in pediatric inflammatory bowel disease, we assessed whether cognitive behavioral therapy (CBT) would differentiate from supportive nondirective therapy in treating depression and disease activity in youth with CD. We also explored whether somatic depressive symptoms showed a different pattern of response in the overall sample and the subset with active inflammatory bowel disease.

METHODS

Youth with depression and CD (n = 161) were randomized to 3 months of CBT (teaching coping skills) or supportive nondirective therapy (supportive listening). Depressive severity was measured using the Children's Depression Rating Scale-Revised (CDRS-R) with the somatic depressive subtype consisting of those CDRS-R items, which significantly correlated with CD activity. Disease activity was measured by the Pediatric Crohn's disease Activity Index. Given the potential confound of higher dose steroids, subanalyses excluded subjects on >20 mg/d prednisone equivalent (n = 34).

RESULTS

Total CDRS-R scores in the overall sample significantly decreased over time after both treatments (P < 0.0001). Treatment with CBT was associated with a significantly greater improvement in the Pediatric Crohn's disease Activity Index (P = 0.05) and somatic depressive subtype (P = 0.03) in those with active inflammatory bowel disease (n = 95) compared with supportive nondirective therapy. After excluding those on steroids (n = 34), there was a significant improvement in total CDRS-R (P = 0.03) and in Pediatric Crohn's disease Activity Index (P = 0.03) after CBT.

CONCLUSIONS

Psychotherapy may be a useful adjunct to treat depression in the context of CD-related inflammation in youth who are not concurrently on higher dose steroids.

Fibromyalgia symptoms and cirrhosis

BACKGROUND

An association between fibromyalgia and hepatitis C virus (HCV) has been previously described. However, the relationship between nonalcoholic steatohepatitis (NASH) and fibromyalgia symptoms has not been assessed, though they share several risk factors.

AIM

We aimed to assess the factors associated with fibromyalgia symptoms across etiologies of liver disease.

METHODS

Patients with cirrhosis due to HCV, NASH, or alcohol were recruited from an outpatient hepatology clinic and administered the Hospital Anxiety and Depression Score, Pittsburgh Sleep Quality Index, and the modified 2010 American College of Rheumatology Diagnostic Criteria for Fibromyalgia. Serum inflammatory markers were measured with standard luminex assays.

RESULTS

Of 193 participants, 53 (27 %) met criteria for fibromyalgia. Fibromyalgia symptoms were significantly associated with etiology of liver disease (HCV: 35 %, NASH: 30 %, alcohol-related liver disease: 12 %, p < 0.01). Using logistic regression, mood symptoms (OR 1.14, 95 % CI 1.06, 1.22), sleep disturbance (OR 1.32, 95 % CI 1.16, 1.52), and etiology of liver disease (NASH vs. HCV not different, alcohol vs. HCV OR 0.19, 95 % CI 0.05, 0.63) were associated with fibromyalgia symptoms. If abdominal pain was included in the model, etiology became nonsignificant, indicating that it may be central sensitization due to abdominal pain in patients with chronic liver disease that explains fibromyalgia symptoms rather than the etiology of liver disease or inflammation.

CONCLUSIONS

Fibromyalgia symptoms were significantly associated with HCV and NASH cirrhosis and with psychiatric symptoms. Future work should focus on the underlying pathophysiology and management of widespread pain in patients with cirrhosis.

Brain-derived neurotrophic factor levels in late-life depression and comorbid mild cognitive impairment: a longitudinal study

Changes in brain-derived neurotrophic factor (BDNF) level are implicated in the pathophysiology of cognitive decline in depression and neurodegenerative disorders in older adults. We aimed to evaluate the longitudinal association over two years between BDNF and persistent cognitive decline in individuals with remitted late-life depression and Mild Cognitive Impairment (LLD + MCI) compared to either individuals with remitted LLD and no cognitive decline (LLD + NCD) or never-depressed, cognitively normal, elderly control participants. We additionally evaluated the effect of double-blind, placebo-controlled donepezil treatment on BDNF levels in all of the remitted LLD participants (across the levels of cognitive function). We included 160 elderly participants in this study (72 LLD + NCD, 55 LLD + MCI and 33 never-depressed cognitively normal elderly participants). At the same visits, cognitive assessments were conducted and blood sampling to determine serum BDNF levels were collected at baseline assessment and after one and two years of follow-up. We utilized repeated measure, mixed effect models to assess: (1) the effects of diagnosis (LLD + MCI, LLD + NCD, and controls), time, and their interaction on BDNF levels; and (2) the effects of donepezil treatment (donepezil vs. placebo), time, baseline diagnosis (LLD + MCI vs. LLD + NCD), and interactions between these contrasts on BDNF levels. We found a significant effect of time on BDNF level (p = 0.02) and a significant decline in BDNF levels over 2 years of follow-up in participants with LLD + MCI (p = 0.004) and controls (p = 0.04). We found no effect of donepezil treatment on BDNF level. The present results suggest that aging is an important factor related to decline in BDNF level. Clinicaltrials.gov Identifier: NCT00177671.

Inflammatory cytokines, growth factors, and depression

There is a plausible role for cytokines, brain-derived neurotrophic factor (BDNF), and their interaction in major depressive disorder's (MDD) etiology. This review includes (i) briefly defining cytokines, (ii) a discussion of theories for why they may affect brain function, (iii) cross-sectional associations between cytokines and MDD, (iv) the effect of antidepressants on cytokines, (v) the behavioral effects of cytokines administration to humans, (vi) the behavior effects of their administration to animal models, and (vii) potential neurochemical systems influenced by cytokines. The role of BDNF is then briefly examined, along with a review of several studies that have examined a Val/Met polymorphism in the BDNF gene. The bidirectional relationship between BDNF and cytokines is subsequently discussed. Potential ramifications for MDD treatment that are appraised include (i) use of cytokine biomarkers for identifying specific populations for targeted MDD therapy, (ii) the use of medications that directly antagonize the role of inflammatory cytokines, (iii) potential indirect modifiers of cytokine activity, and (iv) possible downstream intracellular second messenger targets.

Preliminary findings regarding proinflammatory markers and brain-derived neurotrophic factor among adolescents with bipolar spectrum disorders

Mood symptoms in adult bipolar disorder are associated with increased proinflammatory markers and decreased brain-derived neurotrophic factor (BDNF). We examined serum interleukin-6, high-sensitivity C-reactive protein (hsCRP), and BDNF among 30 bipolar disorder adolescents. Hypomanic/manic symptoms were positively associated with hsCRP. BDNF levels were negatively associated with interleukin-6. Forty percent had cardiovascular high-risk hsCRP levels. Larger longitudinal studies are warranted.

Predicting 6-week treatment response to escitalopram pharmacotherapy in late-life major depressive disorder

OBJECTIVE

Approximately half of older patients treated for major depressive disorder (MDD) do not achieve symptomatic remission and functional recovery with first-line pharmacotherapy. This study aims to characterize sociodemographic, clinical, and neuropsychologic correlates of full, partial, and non-response to escitalopram monotherapy of unipolar MDD in later life.

METHODS

One hundred and seventy-five patients aged 60 and older were assessed at baseline on demographic variables, depression severity, hopelessness, anxiety, cognitive functioning, co-existing medical illness burden, social support, and quality of life (disability). Subjects received 10 mg/d of open-label escitalopram and were divided into full (n = 55; 31%), partial (n = 75; 42.9%), and non-responder (n = 45; 25.7%) groups based on Hamilton depression scores at week 6. Univariate followed by multivariate analyses tested for differences between the three groups.

RESULTS

Non-responders to treatment were found to be more severely depressed and anxious at baseline than both full and partial responders, more disabled, and with lower self-esteem than full responders. In general partial responders resembled full responders more than they resembled non-responders. In multivariate models, more severe anxiety symptoms (both psychological and somatic) and lower self-esteem predicted worse response status at 6 weeks.

CONCLUSION

Among treatment-seeking elderly persons with MDD, higher anxiety symptoms and lower self-esteem predict poorer response after six weeks of escitalopram treatment.

Association of the serotonin transporter gene-linked polymorphic region (5-HTTLPR) genotype with depression in elderly persons after hip fracture

OBJECTIVE

The authors examined the serotonin transporter gene-linked polymorphic region (5-HTTLPR) as a predictor of major depressive disorder and depressive symptoms after hip fracture, a common stressful medical event.

METHODS

This was a prospective, observational study of 23 elderly rehabilitation-hospital patients during their inpatient stay. Depressive symptoms were assessed by Hamilton Rating Scale for Depression (Ham-D) and PRIME-MD. Subjects were also genotyped for 5-HTTLPR.

RESULTS

Survival analysis showed that genotype significantly predicted time-to-major depressive episode. Subjects with an s allele (genotype s/l or s/s) had significantly higher Ham-D scores over 14 weeks of follow-up than those with the l/l genotype.

CONCLUSION

Depressive symptoms and major depressive disorder in elderly persons after a stressful medical event may be associated with 5-HTTLPR genotype. This finding requires confirmation in a larger sample.

Achieving long-term optimal outcomes in geriatric depression and anxiety

Depression and anxiety disorders are very common in the elderly. Data accumulated over the past 2 decades have shown that most older patients can tolerate and respond to acute treatment with serotonergic antidepressants, other psychotropic agents, or manual-based psychotherapy. However, outcomes under usual-care conditions remain poor. This review proposes that clinicians may significantly improve the long-term outcomes of their older patients with depression and anxiety by focusing on four key factors: (1) identification and treatment of comorbid conditions; (2) full remission of acute symptoms; (3) education of patients, families, and professional colleagues about the need for long-term treatment; and (4) prevention and management of medication side-effects.

Genetic differences in behavioral sensitivity to a neuroactive steroid

Recent work found that lower endogenous levels of the gamma-aminobutyric acid-agonist, neuroactive steroid 3alpha-hydroxy-5alpha-pregnan-20-one (3alpha,5alpha-THP) may be correlated with increased ethanol withdrawal severity in the selectively bred Withdrawal Seizure-Prone and -Resistant mice. The present studies were conducted to determine whether decreased sensitivity to 3alpha,5alpha-THP was correlated with ethanol withdrawal hyperexcitability in another genetic mouse model, namely the C57BL/6 (B6) and DBA/2 (D2) inbred strains. These strains also differ in ethanol withdrawal severity (D2 >> B6). B6 and D2 male mice were injected with 3alpha,5alpha-THP (0-10 mg/kg i.p.) 15 min before the timed tail vein infusion of pentylenetetrazol. B6 mice were more sensitive than D2 animals to the anticonvulsant effect of 3alpha,5alpha-THP. Subsequent studies measured sensitivity to several of the pharmacological effects of 3alpha,5alpha-THP. B6 and D2 male mice were injected with 3alpha,5alpha-THP (0-32 mg/kg) before testing for locomotor activation (total number of entries) and anxiolysis (percent open arm entries) on the elevated plus maze, muscle relaxation (impairment of forelimb grip strength), ataxia (impairment of Rotarod performance) and seizure susceptibility to pentylenetetrazol. B6 mice were more sensitive than D2 animals to the anxiolytic, locomotor stimulant and anticonvulsant effects of 3alpha,5alpha-THP. In contrast, D2 mice were more sensitive than B6 mice to 3alpha,5alpha-THP-induced muscle relaxation and ataxia. Plasma 3alpha,5alpha-THP levels did not differ in the B6 and D2 mice injected with this steroid, suggesting that the strain differences were not pharmacokinetic. Collectively, the results in selectively bred Withdrawal Seizure-Prone and -Resistant mice and B6 and D2 inbred strains suggest that genetic differences in neuroactive steroid sensitivity and biosynthesis may contribute to ethanol withdrawal severity.