Effects of Anxious Depression on Antidepressant Treatment Response

Anxious depression represents a subtype of major depressive disorder and is associated with increased suicidality, severity, chronicity and lower treatment response. Only a few studies have investigated the differences between anxious depressed (aMDD) and non-anxious depressed (naMDD) patients regarding treatment dosage, serum-concentration and drug-specific treatment response. In our naturalistic and prospective study, we investigated whether the effectiveness of therapy including antidepressants (SSRI, SNRI, NaSSA, tricyclics and combinations) in aMDD patients differs significantly from that in naMDD patients. In a sample of 346 patients, we calculated the anxiety somatization factor (ASF) and defined treatment response as a reduction (≥50%) in the Hamilton Depression Rating Scale (HDRS)-21 score after 7 weeks of pharmacological treatment. We did not observe an association between therapy response and the baseline ASF-scores, or differences in therapy outcomes between aMDD and naMDD patients. However, non-responders had higher ASF-scores, and at week 7 aMDD patients displayed a worse therapy outcome than naMDD patients. In subgroup analyses for different antidepressant drugs, venlafaxine-treated aMDD patients showed a significantly worse outcome at week 7. Future prospective, randomized-controlled studies should address the question of a worse therapy outcome in aMDD patients for different psychopharmaceuticals individually.

Deep phenotyping as a contribution to personalized depression therapy: the GEParD and DaCFail protocols

Depressive patients suffer from a complex of symptoms of varying intensity compromising their mood, emotions, self-concept, neurocognition, and somatic function. Due to a mosaic of aetiologies involved in developing depression, such as somatic, neurobiological, (epi-)genetic factors, or adverse life events, patients often experience recurrent depressive episodes. About 20-30% of these patients develop difficult-to-treat depression. Here, we describe the design of the GEParD (Genetics and Epigenetics of Pharmaco- and Psychotherapy in acute and recurrent Depression) cohort and the DaCFail (Depression-associated Cardiac Failure) case-control protocol. Both protocols intended to investigate the incremental utility of multimodal biomarkers including cardiovascular and (epi-)genetic markers, functional brain and heart imaging when evaluating the response to antidepressive therapy using comprehensive psychometry. From 2012 to 2020, 346 depressed patients (mean age 45 years) were recruited to the prospective, observational GEParD cohort protocol. Between 2016 and 2020, the DaCFail case-control protocol was initiated integrating four study subgroups to focus on heart-brain interactions and stress systems in patients > 50 years with depression and heart failure, respectively. For DaCFail, 120 depressed patients (mean age 60 years, group 1 + 2), of which 115 also completed GEParD, and 95 non-depressed controls (mean age 66 years) were recruited. The latter comprised 47 patients with heart failure (group 3) and 48 healthy subjects (group 4) of a population-based control group derived from the Characteristics and Course of Heart Failure Stages A-B and Determinants of Progression (STAAB) cohort study. Our hypothesis-driven, exploratory study design may serve as an exemplary roadmap for a standardized, reproducible investigation of personalized antidepressant therapy in an inpatient setting with focus on heart comorbidities in future multicentre studies.

Effects of Pharmacokinetic Gene Variation on Therapeutic Drug Levels and Antidepressant Treatment Response

Introduction Pharmacogenetic testing is proposed to minimize adverse effects when considered in combination with pharmacological knowledge of the drug. As yet, limited studies in clinical settings have investigated the predictive value of pharmacokinetic (pk) gene variation on therapeutic drug levels as a probable mechanism of adverse effects, nor considered the combined effect of pk gene variation and drug level on antidepressant treatment response.

Methods Two depression cohorts were investigated for the relationship between pk gene variation and antidepressant serum concentrations of amitriptyline, venlafaxine, mirtazapine and quetiapine, as well as treatment response. For the analysis, 519 patients (49% females; 46.6±14.1 years) were included.

Results Serum concentration of amitriptyline was associated with CYP2D6 (higher concentrations in poor metabolizers compared to normal metabolizers), of venlafaxine with CYP2C19 (higher concentrations in intermediate metabolizers compared to rapid/ultrarapid metabolizers) and CYP2D6 (lower metabolite-to-parent ratio in poor compared to intermediate and normal metabolizers, and intermediate compared to normal and ultrarapid metabolizers). Pk gene variation did not affect treatment response.

Discussion The present data support previous recommendations to reduce starting doses of amitriptyline and to guide dose-adjustments via therapeutic drug monitoring in CYP2D6 poor metabolizers. In addition, we propose including CYP2C19 in routine testing in venlafaxine-treated patients to improve therapy by raising awareness of the risk of low serum concentrations in CYP2C19 rapid/ultrarapid metabolizers. In summary, pk gene variation can predict serum concentrations, and thus the combination of pharmacogenetic testing and therapeutic drug monitoring is a useful tool in a personalized therapy approach for depression.

Inhibition of acid sphingomyelinase increases regulatory T cells in humans

Genetic deficiency for acid sphingomyelinase or its pharmacological inhibition has been shown to increase Foxp3⁺ regulatory T-cell frequencies among CD4⁺ T cells in mice. We now investigated whether pharmacological targeting of the acid sphingomyelinase, which catalyzes the cleavage of sphingomyelin to ceramide and phosphorylcholine, also allows to manipulate relative CD4⁺ Foxp3⁺ regulatory T-cell frequencies in humans. Pharmacological acid sphingomyelinase inhibition with antidepressants like sertraline, but not those without an inhibitory effect on acid sphingomyelinase activity like citalopram, increased the frequency of Foxp3⁺ regulatory T cell among human CD4⁺ T cells in vitro. In an observational prospective clinical study with patients suffering from major depression, we observed that acid sphingomyelinase-inhibiting antidepressants induced a stronger relative increase in the frequency of CD4⁺ Foxp3⁺ regulatory T cells in peripheral blood than acid sphingomyelinase-non- or weakly inhibiting antidepressants. This was particularly true for CD45RA⁻ CD25^high effector CD4⁺ Foxp3⁺ regulatory T cells. Mechanistically, our data indicate that the positive effect of acid sphingomyelinase inhibition on CD4⁺ Foxp3⁺ regulatory T cells required CD28 co-stimulation, suggesting that enhanced CD28 co-stimulation was the driver of the observed increase in the frequency of Foxp3⁺ regulatory T cells among human CD4⁺ T cells. In summary, the widely induced pharmacological inhibition of acid sphingomyelinase activity in patients leads to an increase in Foxp3⁺ regulatory T-cell frequencies among CD4⁺ T cells in humans both in vivo and in vitro.

Stress impairs response to antidepressants via HPA axis and immune system activation

Childhood trauma as well as severe events occurring later in life have been associated with the development of major depressive disorder (MDD). However, the interaction of early and later occurring adverse events in patients with MDD is understudied. This study aims to disentangle this interaction by investigating the effects on two of the main stress-response systems of the body, the hypothalamic-pituitaryadrenal (HPA-) axis and the immune system in depressed patients. The function of the HPA-axis was assessed by measuring FKBP5, SGK1 and NR3C1 mRNA-expression in peripheral blood after an in vivo glucocorticoid receptor (GR) challenge with 1.5 mg dexamethasone in 150 depressed in-patients (47.4% females). Childhood trauma was evaluated using the Childhood Trauma Questionnaire (CTQ), severe life events occurring one year prior to hospital admission were assessed with the List of Threatening Experiences (LTE). Multiple childhood traumata, i.e. ≥ 3, were present in 68 (45.5%) patients, 59 (39.3%) experienced ≥ 3 severe recent life events. The history of ≥ 3 severe recent life events was associated with an impaired GR-induction of SGK1 (F = 10.455; df = 1; p = 0.002) and FKBP5 mRNA expression (F = 8.720; df = 1; p = 0.004), and with elevated measures of the immune system such as CRP and lymphocyte count. In addition, severe recent life events were associated with a substantially impaired treatment response to antidepressants (F = 7.456; df = 1; p = 0.008). These effects could not be observed in relation to childhood trauma. Severe life events occurring prior to MDD development substantially impaired the stress-response systems and the response to treatment with antidepressants. This finding may indicate the need to employ additional treatment options such as psychotherapy right at the beginning of treatment or immune-modulating approaches.

Impaired fear learning and extinction, but not generalization, in anxious and non-anxious depression

Fear conditioning and generalization are well-known mechanisms in the pathogenesis of anxiety disorders. Extinction of conditioned fear responses is crucial for the psychotherapeutic treatment of these diseases. Anxious depression as a subtype of major depression shares characteristics with anxiety disorders. We therefore aimed to compare fear learning mechanisms in patients with anxious versus non-anxious depression. Fear learning mechanisms in patients with major depression (n = 79; for subgroup analyses n = 41 patients with anxious depression and n = 38 patients with non-anxious depression) were compared to 48 healthy participants. We used a well-established differential fear conditioning paradigm investigating acquisition, generalization, and extinction. Ratings of valence, arousal and probability of expected threat were assessed as well as skin conductance response as an objective psychophysiological measure. Patients with major depression showed impaired acquisition of conditioned fear. In addition, depressed patients showed impaired extinction of conditioned fear responses after successful fear conditioning. Generalization was not affected. However, there was no difference between patients with anxious and non-anxious depression. Results differed between objective and subjective measures. Our findings show altered fear acquisition and extinction in major depression as compared to healthy controls, but they do not favor differential fear learning and extinction mechanisms in the pathogenesis of anxious versus non-anxious depression. The results of impaired extinction warrant future studies addressing extinction learning elements in the treatment of depression.

Higher venlafaxine serum concentrations necessary for clinical improvement? Time to re-evaluate the therapeutic reference range of venlafaxine

BACKGROUND

The therapeutic reference range for venlafaxine in antidepressant treatment has been defined as 100 to 400 ng/mL. However, in an everyday setting active moiety concentrations above the therapeutic reference range were often reported.

AIM

The aim of this study was to re-evaluate the therapeutic reference range of venlafaxine.

METHODS

In-patients (⩽60 years) with major depressive episodes receiving antidepressant monotherapy with venlafaxine during routine clinical treatment were included in this observational study. Depressive symptom severity was evaluated on a weekly basis using the Hamilton Depression Rating Scale (HAMD-21), and therapeutic drug monitoring analyses were performed. Resting electrocardiograms were analyzed in week 3, week 5 and week 7 of study participation.

RESULTS

Clinical improvement from baseline to week 4 was significantly associated with increasing serum concentrations of the active moiety of venlafaxine (N = 23, Pearson correlation, p = 0.009), but not with the dose of venlafaxine. Patients achieving remission showed significantly higher serum concentrations than patients achieving response/non-response (Kruskal-Wallis test, p = 0.019). Moreover, in patients with serum concentrations above 400 ng/mL time to remission and time to response was significantly shorter than in patients with concentrations below 400 ng/mL (Mantel-COX test, p = 0.001; p = 0.010). QTc time was below the upper limit of a normal QTc time (450 ms) for all patients.

CONCLUSION

The serum concentration of the active moiety and not the dose determined the effect of venlafaxine. Shorter remission times without ECG alterations in patients with serum concentrations above the therapeutic reference range suggest a re-evaluation of the therapeutic reference range for venlafaxine in larger studies.

Extent of cortisol suppression at baseline predicts improvement in HPA axis function during antidepressant treatment

BACKGROUND

A dysregulation in the hypothalamic-pituitary-adrenal (HPA)-axis function has been repeatedly observed in major depressive disorders (MDD). Normalization of this dysregulation, i.e. of cortisol suppression after glucocorticoid receptor (GR)-stimulation, may be mandatory for clinical remission in some patient subgroups. However, there are no biological measures applied in the clinical setting to identify patient subgroups with HPA axis alterations.

OBJECTIVE

We aimed to define a suppression index of cortisol concentrations before and after GR stimulation with dexamethasone to predict the variability in improvement of HPA axis activity during antidepressant treatment.

METHODS

A modified dexamethasone suppression test (mDST) was performed with blood withdrawal for cortisol and ACTH measurement before and 3 h after 1.5 mg dexamethasone intake at 18:00 in two cohorts of depressed patients treated in a naturalistic setting. The discovery sample consisted of 106 patients, the replication sample of 117 patients. The suppression index was defined as cCORTpreDEXcCORTpostDEX.

RESULTS

The baseline suppression index explained 27.4 % of the variance in changes of HPA axis activity before and after treatment with antidepressants. Age, cCORTpreDEXcACTHpreDEX at baseline and sex explained further variance up to 56.2 % (stepwise linear regression, p = 7.8e^-8). A threshold of the suppression index at baseline was determined by ROC analysis and revealed, that only patients with a maximum index of 2.32 achieved a normalization of the HPA axis activity after antidepressant treatment. In the replication sample, the threshold was 2.86. However, the estimated suppression index was not associated with treatment response.

CONCLUSION

For the first time, by establishing a short-term suppression index of cortisol before and after GR-stimulation a threshold could be identified to predict improvement of HPA axis activity during antidepressant therapy. After replication in further studies this index may help to identify patients who benefit from a specific treatment that targets components of the HPA axis in the future.

Covariation bias in depression - a predictor of treatment response?

Covariation bias, defined as an overestimation of the relationship between fear-relevant stimuli and aversive consequences, is a well-investigated cognitive bias in anxiety disorders. As patients with affective disorders also show biased information processing, the aim of the present study was to investigate whether depressed patients also display a covariation bias between negative stimuli and aversive consequences. Covariation estimates of 62 inpatients with a current severe depressive episode were assessed at admission (n = 31) or after 6 weeks of treatment (n = 31) and were compared in a between-group design with 31 age- and sex-matched healthy controls. All participants showed a covariation bias for the relationship between negative stimuli and aversive consequences. Moreover, covariation bias at admission was significantly associated with various clinician- and self-reported dimensional measures of treatment response assessed 6 weeks later (Global Assessment of Functioning, Clinical Global Impression Scale, and Beck Depression Inventory), i.e., patients with a stronger bias showed greater impairment after 6 weeks of treatment. Categorical analyses revealed that overall, treatment non-responders-but not responders-were characterized by a covariation bias. The naturalistic study design without standardized pharmacological and psychotherapeutic treatments is a central limitation. We conclude that the covariation bias may constitute a possible marker in the field of emotional information processing in the search for effective predictors of therapy outcome.

Childhood trauma dependent anxious depression sensitizes HPA axis function

Anxious depression is a common subtype of major depressive disorder (MDD) and is associated with greater severity and poorer outcome. Alterations of the hypothalamic-pituitary-adrenal (HPA) axis, especially of the glucocorticoid receptor (GR) function, are often observed in MDD, but evidence lacks for anxious depression. Childhood adversity is known to influence both the HPA axis and risk of MDD. Therefore, we investigated GR-function in anxious depression dependent on childhood adversity. We enrolled 144 depressed in-patients (49.3% females). Anxious depression was defined using the Hamilton Depression Rating Scale (HAM-D) anxiety/somatization factor score ≥7. Blood draws were performed at 6 pm before and 3 h after 1.5 mg dexamethasone ingestion for measurement of cortisol, ACTH and blood count to assess GR-function and the immune system. In a subgroup of n = 60 FKBP5 mRNA controlled for FKBP5 genotype was measured before and after dexamethasone. Childhood adversity was evaluated using the Childhood Trauma Questionnaire (CTQ). We identified 78 patients (54.2%) with anxious depression who showed a greater severity and worse outcome. These patients were more often exposed to sexual abuse (30% vs. 16%/p = 0.04) and emotional neglect (76% vs. 58%/p = 0.02) than patients with non-anxious depression. Anxious depressed patients showed an enhanced GR-induced FKBP5 mRNA expression (F = 5.128; p = 0.03) and reduced cortisol levels, partly dependent on sexual abuse (F = 7.730; p = 0.006). Additionally, the GR-induced leukocyte response was enhanced in patients with sexual abuse (F = 7.176; p = 0.008). Anxious depression in dependence of childhood trauma is associated with heightened sensitivity of the HPA axis and the immune system which should be considered for treatment algorithms and targets.