Personality traits as risk factors for treatment-resistant depression

Treatment resistant late-life depression: A narrative review of psychosocial risk factors, non-pharmacological interventions, and the role of clinical phenotyping

BACKGROUND

Treatment resistant depression (TRD) is a subset of major depressive disorder (MDD) in which symptoms do not respond to front line therapies. In older adults, the assessment and treatment of TRD is complicated by psychosocial risk factors unique to this population, as well as a relative paucity of research.

METHODS

Narrative review aimed at (1) defining TRLLD for clinical practice and research; (2) describing psychosocial risk factors; (3) reviewing psychological and non-pharmacological treatments; (4) discussing the role of clinical phenotyping for personalized treatment; and (5) outlining research priorities.

RESULTS

Our definition of TRLLD centers on response to medication and neuromodulation in primary depressive disorders. Psychosocial risk factors include trauma and early life adversity, chronic physical illness, social isolation, personality, and barriers to care. Promising non-pharmacological treatments include cognitive training, psychotherapy, and lifestyle interventions. The utility of clinical phenotyping is highlighted by studies examining the impact of comorbidities, symptom dimensions (e.g., apathy), and structural/functional brain changes.

LIMITATIONS

There is a relative paucity of TRLLD research. This limits the scope of empirical data from which to derive reliable patterns and complicates efforts to evaluate the literature quantitatively.

CONCLUSIONS

TRLLD is a complex disorder that demands further investigation given our aging population. While this review highlights the promising breadth of TRLLD research to date, more research is needed to help elucidate, for example, the optimal timing for implementing risk mitigation strategies, the value of collaborative care approaches, specific treatment components associated with more robust response, and phenotyping to help inform treatment decisions.

Temperament and character dimensions explain self-reported resilience deficits in patients with affective disorders

This is the first study exploring how temperament and character personality dimensions impact self-reported resilience in major depressive disorder (MDD) and bipolar disorder (BD). We included 130 euthymic patients with affective disorders (AFD; 66 MDD and 64 BD) and 134 healthy controls (HC). Connor and Davidson resilience scale and Temperament and Character Inventory (TCI-140) were administered. Multiple linear regressions and interaction analyses were performed. Mediation analyses examined if personality dimensions explained group differences in resilience. Resilience was lower in MDD and BD vs. HC and in MDD vs. BD, adjusting for sex, age and education. Higher resilience was predicted by lower harm avoidance (HA) and higher persistence (P) in AFD and MDD, lower HA in BD and higher P and self-directedness (SD) in HC. However, only HA and P had a group-specific effect on resilience in AFD vs. HC. In mediation analyses, specific TCI dimensions at least partially explained differences in resilience: HA, P and SD in AFD or MDD vs. HC; SD in BD vs. HC; P in BD vs. MDD. Concludingly, two temperament traits (HA, P) and a character trait (SD) predict resilience in AFD. Focusing on personality could identify sources of compromised resilience as potential treatment targets.

Predicting treatment outcome in depression: an introduction into current concepts and challenges

Improving response and remission rates in major depressive disorder (MDD) remains an important challenge. Matching patients to the treatment they will most likely respond to should be the ultimate goal. Even though numerous studies have investigated patient-specific indicators of treatment efficacy, no (bio)markers or empirical tests for use in clinical practice have resulted as of now. Therefore, clinical decisions regarding the treatment of MDD still have to be made on the basis of questionnaire- or interview-based assessments and general guidelines without the support of a (laboratory) test. We conducted a narrative review of current approaches to characterize and predict outcome to pharmacological treatments in MDD. We particularly focused on findings from newer computational studies using machine learning and on the resulting implementation into clinical decision support systems. The main issues seem to rest upon the unavailability of robust predictive variables and the lacking application of empirical findings and predictive models in clinical practice. We outline several challenges that need to be tackled on different stages of the translational process, from current concepts and definitions to generalizable prediction models and their successful implementation into digital support systems. By bridging the addressed gaps in translational psychiatric research, advances in data quantity and new technologies may enable the next steps toward precision psychiatry.

Effects of the Interaction between Affective Temperaments and BIS/BAS on Depressive Symptoms in Individuals with Major Depressive Disorder

Depressive symptoms (DepS) associated with major depressive disorder (MDD) are influenced by affective temperaments (ATs), behavioral inhibition system (BIS), and behavioral activation system (BAS). However, the effect of interactions between ATs and BIS/BAS on DepS in MDD remains poorly understood. Herein, we aimed to investigate the effects of these interactions. The Temperament Evaluation of Memphis, Pisa, Paris, and San Diego Auto-questionnaire (TEMPS-A), BIS/BAS questionnaire, and Patient Health Questionnaire-9 (PHQ-9) were used to evaluate ATs, BIS/BAS, and DepS, respectively, in 90 participants with MDD. Data were analyzed using hierarchical multiple regression analysis to assess the interaction effect. The interaction (β = 0.199, p < 0.05) between depressive temperament (DepT) (β = 0.319, p < 0.01) and BIS scores (β = 0.300, p < 0.01) exhibited a significant positive effect on DepS (ΔR2 = 0.038, p < 0.05). However, the interaction between ATs and BAS scores did not exhibit a significant effect on DepS. Our findings suggest that interactions between BIS sensitivity and DepT worsen DepS in individuals with MDD. Hence, to manage DepS associated with BIS sensitivity and DepT, evaluating their interaction may be useful in daily clinical practice. This study presents important insights into MDD psychopathology.

Brainstem glucose metabolism predicts reward dependence scores in treatment-resistant major depression

BACKGROUND

It has been suggested that individual differences in temperament could be involved in the (non-)response to antidepressant (AD) treatment. However, how neurobiological processes such as brain glucose metabolism may relate to personality features in the treatment-resistant depressed (TRD) state remains largely unclear.

METHODS

To examine how brainstem metabolism in the TRD state may predict Cloninger's temperament dimensions Harm Avoidance (HA), Novelty Seeking (NS), and Reward Dependence (RD), we collected ¹⁸fluorodeoxyglucose positron emission tomography (¹⁸FDG PET) scans in 40 AD-free TRD patients. All participants were assessed with the Temperament and Character Inventory (TCI). We applied a multiple kernel learning (MKL) regression to predict the HA, NS, and RD from brainstem metabolic activity, the origin of respectively serotonergic, dopaminergic, and noradrenergic neurotransmitter (NT) systems.

RESULTS

The MKL model was able to significantly predict RD but not HA and NS from the brainstem metabolic activity. The MKL pattern regression model identified increased metabolic activity in the pontine nuclei and locus coeruleus, the medial reticular formation, the dorsal/median raphe, and the ventral tegmental area that contributed to the predictions of RD.

CONCLUSIONS

The MKL algorithm identified a likely metabolic marker in the brainstem for RD in major depression. Although ¹⁸FDG PET does not investigate specific NT systems, the predictive value of brainstem glucose metabolism on RD scores however indicates that this temperament dimension in the TRD state could be mediated by different monoaminergic systems, all involved in higher order reward-related behavior.

Epidemiology of treatment resistant depression among major depressive disorder patients in Israel

INTRODUCTION

Major depressive disorder (MDD) is one of the most common mental disorders worldwide, estimated to affect 10-15% of the population per year. Treatment resistant depression (TRD) is estimated to affect a third of these patients who show difficulties in social and occupational function, decline of physical health, suicidal thoughts and increased health care utilization. We describe the prevalence of MDD, TRD and associated healthcare resource utilization in Maccabi Healthcare Services (MHS), a 2.5 million-member state-mandated health service in Israel.

METHODS

All MHS members with an MDD diagnosis were identified within the years 2017-2018 and prevalence assessed by age, sex and TRD. To assess the incidence of MDD, members aged 18-65 years at the start of any MDD episode were identified between 1^st January 2016 and 31^st May 2018 with at least one systemic first-line antidepressant treatment within three months before or after the initial episode. Treatment patterns, time on first-line treatment, and healthcare resource utilization were compared by TRD.

RESULTS

A total of 4960 eligible MDD patients were identified (median age = 51 years, 65% female), representing a period prevalence of 0.218%, and of those, a high proportion of patients received drug treatment (92%). Among incident MDD cases (n = 2553), 24.4% had TRD. Factors associated with TRD included increasing age and personality disorder. Median time on treatment was 3.7 months (longer for those without TRD than those with) and 81.9% of patients purchased more than one month's supply of therapy. In the year after index, patients with TRD had a significant increased number of visits to primary care physicians, psychiatrists, emergency room visits, general hospitalizations, and psychiatric hospitalizations.

CONCLUSION

Our study shows that prevalence of MDD in Israel is low compared to other countries, however once diagnosed, patients' are likely to receive drug treatment. Among patients diagnosed with MDD, the proportion of TRD is similar to other countries, increases with age and is associated with increased healthcare utilization, therefore should be a focus of continued research for finding effective long term treatment options.

Personality Related to Quality-of-Life Improvement After Deep Brain Stimulation in Parkinson's Disease (PSYCHO-STIM II)

BACKGROUND

Deep brain stimulation of the sub-thalamic nucleus (DBS-STN) reduces symptoms in Parkinson's disease (PD) patients with motor fluctuations. However, some patients may not feel ameliorated afterwards, despite an objective motor improvement. It is thus important to find new predictors of patients' quality of life (QoL) amelioration after DBS-STN. We hypothesized that personality dimensions might affect QoL after DBS-STN.

OBJECTIVE

To evaluate associations between personality dimensions and QoL improvement one year after DBS-STN.

METHODS

DBS-STN-PD patients (n = 303) having answered the "Temperament and Character Inventory" (TCI) before surgery and the PDQ-39 before and one year after surgery were included, from the cohort study PREDI-STIM. Linear regression models were used to evaluate associations between TCI dimensions and change in PDQ-39 scores after DBS-STN.

RESULTS

Novelty Seeking and Cooperativeness scores before surgery were positively associated with PDQ-39 scores improvement after DBS-STN (FDR-adjusted p < 0.01). Moreover, paradoxically unimproved patients with deterioration of their PDQ-39 scores after DBS-STN despite improvement of their MDS-UPDRS-IV scores had lower Cooperativeness scores, while paradoxically improved patients with amelioration of their PDQ-39 scores despite deterioration of their MDS-UPDRS-IV scores had higher Reward Dependence scores.

CONCLUSION

Some presurgical personality dimensions were significantly associated with QoL amelioration and discrepancy between motor state and QoL changes after DBS-STN in PD. Educational programs before DBS-STN should take in account patient personality dimensions to better deal with their expectations.

Reinforcement sensitivity predicts affective psychopathology via emotion regulation: Cross-sectional, longitudinal and quasi-experimental evidence

The current article presents a model wherein reinforcement sensitivity predicts depression and anxiety via trait preferences for concomitant emotion regulation strategies. In Study 1 (N = 593), BAS sensitivity positively predicted reappraisal and BIS sensitivity negatively predicted it. Reappraisal then negatively predicted depression. BIS sensitivity also predicted rumination, which predicted both depression and anxiety. Study 2a confirmed the model developed in Study 1 with an independent sample (N = 513) and examined the relationships longitudinally. While the cross-sectional relationships were generally maintained, reinforcement sensitivity did not predict reappraisal. In Study 2b, participants (N = 218) were assessed a third time one year later, at the onset of the COVID-19 pandemic. During this stressful time, BAS sensitivity did longitudinally predict reappraisal. These studies highlight the role of emotion regulation in mediating the relationship between reinforcement sensitivity and affective pathology, particularly during times of high stress.

Personality profile and therapeutic response to lithium carbonate and sodium valproate in mania with psychotic features

Bipolar disorder is one of the major psychiatric disorders. Therefore, determining the factors that predict mood stabilizer response is important. This study aimed to investigate the relationship between personality profile and the response to lithium carbonate and sodium valproate in patients with psychotic mania. In this study, 50 patients with bipolar I disorder (manic episode with psychotic features) were randomly assigned to receive lithium carbonate (up to a serum level of 0.8-1.5 mEq/L) or sodium valproate (20 mg/kg). After stabilization of acute manic phase, Temperament and Character Inventory was completed by the patients themselves. Fifty subjects completed this study. The mean age ± SD of participants in the sodium valproate group and lithium carbonate group was 32.99 ± 9.94 and 30.73±7.94 years, respectively. The responders to sodium valproate had significantly higher scores in novelty seeking, harm avoidance (P = 0.003 and 0.004, respectively) and lower scores in persistence (P = 0.006) than the non-responders, but the responders to lithium carbonate did not have significantly different personality profiles. The results of the present study revealed that the personality profiles in the inpatients with psychotic mania are related to the responses to sodium valproate, but are irrelevant to the responses to lithium carbonate.

The endocannabinoid system in humans: significant associations between anandamide, brain function during reward feedback and a personality measure of reward dependence

Preclinical evidence indicates that the endocannabinoid system is involved in neural responses to reward. This study aimed to investigate associations between basal serum concentrations of the endocannabinoids anandamide (AEA) and 2-arachidonylglycerol (2-AG) with brain functional reward processing. Additionally, a personality measure of reward dependence was obtained. Brain functional data were obtained of 30 right-handed adults by conducting fMRI at 3 Tesla using a reward paradigm. Reward dependence was obtained using the subscale reward dependence of the Tridimensional Personality Questionnaire (TPQ). Basal concentrations of AEA and 2-AG were determined in serum. Analyzing the fMRI data, for AEA and 2-AG ANCOVAs were calculated using a full factorial model, with condition (reward > control, loss > control) and concentrations for AEA and 2-AG as factors. Regression analyses were conducted for AEA and 2-AG on TPQ-RD scores. A whole-brain analysis showed a significant interaction effect of AEA concentration by condition (positive vs. negative) within the putamen (x = 26, y = 16, z = -8, F13.51, TFCE_{(1, 54)} = 771.68, k = 70, P_FWE = 0.044) resulting from a positive association of basal AEA concentrations and putamen activity to rewarding stimuli, while this association was absent in the loss condition. AEA concentrations were significantly negatively correlated with TPQ reward dependence scores (r_spearman = -0.56, P = 0.001). These results show that circulating AEA may modulate brain activation during reward feedback and that the personality measure reward dependence is correlated with AEA concentrations in healthy human volunteers. Future research is needed to further characterize the nature of the lipids' influence on reward processing, the impact on reward anticipation and outcome, and on vulnerability for psychiatric disorders.

Treatment-resistant major depressive disorder: Canadian expert consensus on definition and assessment

BACKGROUND

Treatment-resistant depression (TRD) is a debilitating chronic mental illness that confers increased morbidity and mortality, decreases the quality of life, impairs occupational, social, and offspring development, and translates into increased costs on the healthcare system. The goal of this study is to reach an agreement on the concept, definition, staging model, and assessment of TRD.

METHODS

This study involved a review of the literature and a modified Delphi process for consensus agreement. The Appraisal of Guidelines for Research & Evaluation II guidelines were followed for the literature appraisal. Literature was assessed for quality and strength of evidence using the grading, assessment, development, and evaluations system. Canadian national experts in depression were invited for the modified Delphi process based on their prior clinical and research expertize. Survey items were considered to have reached a consensus if 80% or more of the experts supported the statement.

RESULTS

Fourteen Canadian experts were recruited for three rounds of surveys to reach a consensus on a total of 27 items. Experts agreed that a dimensional definition for treatment resistance was a useful concept to describe the heterogeneity of this illness. The use of staging models and clinical scales was recommended in evaluating depression. Risk factors and comorbidities were identified as potential predictors for treatment resistance.

CONCLUSIONS

TRD is a meaningful concept both for clinical practice and research. An operational definition for TRD will allow for opportunities to improve the validity of predictors and therapeutic options for these patients.

Treatment-Resistant Depression Revisited: A Glimmer of Hope

Major Depressive Disorder (MDD) is a highly prevalent psychiatric disorder worldwide. It causes individual suffering, loss of productivity, increased health care costs and high suicide risk. Current pharmacologic interventions fail to produce at least partial response to approximately one third of these patients, and remission is obtained in approximately 30% of patients. This is known as Treatment-Resistant Depression (TRD). The burden of TRD exponentially increases the longer it persists, with a higher risk of impaired functional and social functioning, vast losses in quality of life and significant risk of somatic morbidity and suicidality. Different approaches have been suggested and utilized, but the results have not been encouraging. In this review article, we present new approaches to identify and correct potential causes of TRD, thereby reducing its prevalence and with it the overall burden of this disease entity. We will address potential contributory factors to TRD, most of which can be investigated in many laboratories as routine tests. We discuss endocrinological aberrations, notably, hypothalamic-pituitary-adrenal (HPA) axis dysregulation and thyroid and gonadal dysfunction. We address the role of Vitamin D in contributing to depression. Pharmacogenomic testing is being increasingly used to determine Single Nucleotide Polymorphisms in Cytochrome P450, Serotonin Transporter, COMT, folic acid conversion (MTHFR). As the role of immune system dysregulation is being recognized as potentially a major contributory factor to TRD, the measurement of C-reactive protein (CRP) and select immune biomarkers, where testing is available, can guide combination treatments with anti-inflammatory agents (e.g., selective COX-2 inhibitors) reversing treatment resistance. We focus on established and emerging test procedures, potential biomarkers and non-biologic assessments and interventions to apply personalized medicine to effectively manage treatment resistance in general and TRD specifically.

Post-weaning Social Isolated Flinders Sensitive Line Rats Display Bio-Behavioural Manifestations Resistant to Fluoxetine: A Model of Treatment-Resistant Depression

Treatment-resistant depression (TRD) complicates the management of major depression (MD). The underlying biology of TRD involves interplay between genetic propensity and chronic and/or early life adversity. By combining a genetic animal model of MD and post-weaning social isolation rearing (SIR), we sought to produce an animal that displays more severe depressive- and social anxiety-like manifestations resistant to standard antidepressant treatment. Flinders Sensitive Line (FSL) pups were social or isolation reared from weaning [postnatal day (PND) 21], receiving fluoxetine (FLX) from PND 63 (10 mg/kg × 14 days), and compared to Sprague Dawley (SD) controls. Depressive-, anxiety-like, and social behaviour were assessed from PND 72 in the forced swim test (FST) and social interaction test (SIT). Post-mortem cortico-hippocampal norepinephrine (NE), serotonin (5-HT), and dopamine (DA), as well as plasma interleukin 6 (IL-6), tumour necrosis factor alpha (TNF-α), corticosterone (CORT), and dopamine-beta-hydroxylase (DBH) levels were assayed. FSL rats displayed significant cortico-hippocampal monoamine disturbances, and depressive- and social anxiety-like behaviour, the latter two reversed by FLX. SIR-exposed FSL rats exhibited significant immobility in the FST and social impairment which were, respectively, worsened by or resistant to FLX. In SIR-exposed FSL rats, FLX significantly raised depleted NE and 5-HT, significantly decreased DBH and caused a large effect size increase in DA and decrease in CORT and TNF-α. Concluding, SIR-exposed FSL rats display depressive- and social anxiety-like symptoms that are resistant to, or worsened by, FLX, with reduced plasma DBH and suppressed cortico-hippocampal 5-HT, NE and DA, all variably altered by FLX. Exposure of a genetic animal model of MD to post-weaning SIR results in a more intractable depressive-like phenotype as well as changes in TRD-related biomarkers, that are resistant to traditional antidepressant treatment. Given the relative absence of validated animal models of TRD, these findings are especially promising and warrant study, especially further predictive validation.

Risk and risk factors for disability pension among patients with treatment resistant depression- a matched cohort study

BACKGROUND

Treatment resistant depression (TRD) is common among patients with depression, and is associated with clinical and functional disability. However, the risk and risk factors for being granted disability pension (DP) among patients with TRD have not been investigated.

METHODS

All antidepressant initiators in Sweden with a diagnosis of depression in specialized care were identified in nationwide registers 2006-2013 and followed regarding treatment trials. TRD was defined as the start of a third sequential trial. Patients with TRD who were not on DP (N = 3204) were matched by age, sex, history of depression, calendar year, and time for treatment start with 3204 comparators with depression and ongoing antidepressant treatment. A proportional Cox Regression was performed with DP as outcome, adjusted for various sociodemographic and clinical covariates.

RESULTS

Compared to the comparison cohort, TRD was associated with a doubled risk for all-cause DP (aHR 2.07; 95%CI 1.83-2.35), DP due to depression (2.28; 1.82-2.85) and to any mental disorder (2.24; 1.95-2.57) but not due to somatic diagnoses (1.25; 0.84-1.86). Among significant risk factors for DP in TRD were female sex, being > 29 years of age, unemployment and a diagnosis of comorbid personality disorder (ICD-10 codes F60.0-9).

CONCLUSION

TRD is associated with an elevated risk for DP compared to other patients with depression, with large potential costs for the affected patients and for society. Clinical and therapeutic implications for patients with TRD who are granted DP should be further investigated.

LIMITATION

No clinical data, e.g. type of depression or reason for treatment switch, was available for this study.

Temperament, Character, and Defense Mechanism Changes With Treatment in Depression: A 9-Month Naturalistic Follow-up

The aim of this study was to evaluate the changes in temperament, character, and defense mechanisms with the treatment and remission in patients with major depressive disorder. The study was designed as a longitudinal observational follow-up study of patients with repeated measures at 0, 12, and 36 weeks. In baseline comparisons, the major depression group showed higher harm avoidance and novelty seeking scores and lower self-directness and mature defense styles scores compared with healthy controls. In the follow-up, temperament dimensions and neurotic defenses remained unchanged, mature defense styles and self-directness revealed significant increase, and immature defense styles revealed significant decrease. Although there was no significant difference in the defense styles, harm avoidance and novelty seeking scores remained higher in MDD patients compare with healthy controls in 36 weeks. Our findings regarding continuation of hierarchically upward improvement in defense mechanism after the remission may support importance of treatment after remission.

The identification, assessment and management of difficult-to-treat depression: An international consensus statement

BACKGROUND

Many depressed patients are not able to achieve or sustain symptom remission despite serial treatment trials - often termed "treatment resistant depression". A broader, perhaps more empathic concept of "difficult-to-treat depression" (DTD) was considered.

METHODS

A consensus group discussed the definition, clinical recognition, assessment and management implications of the DTD heuristic.

RESULTS

The group proposed that DTD be defined as "depression that continues to cause significant burden despite usual treatment efforts". All depression management should include a thorough initial assessment. When DTD is recognized, a regular reassessment that employs a multi-dimensional framework to identify addressable barriers to successful treatment (including patient-, illness- and treatment-related factors) is advised, along with specific recommendations for addressing these factors. The emphasis of treatment, in the first instance, shifts from a goal of remission to optimal symptom control, daily psychosocial functional and quality of life, based on a patient-centred approach with shared decision-making to enhance the timely consideration of all treatment options (including pharmacotherapy, psychotherapy, neurostimulation, etc.) to optimize outcomes when sustained remission is elusive.

LIMITATIONS

The recommended definition and management of DTD is based largely on expert consensus. While DTD would seem to have clinical utility, its specificity and objectivity may be insufficient to define clinical populations for regulatory trial purposes, though DTD could define populations for service provision or phase 4 trials.

CONCLUSIONS

DTD provides a clinically useful conceptualization that implies a search for and remediation of specific patient-, illness- and treatment obstacles to optimizing outcomes of relevance to patients.

Temperament and character influence on depression treatment outcome

BACKGROUND

personality features have been repeatedly associated with depression treatment outcome in Major Depressive Disorder (MDD), however conclusive results are still lacking. Moreover, as for Bipolar Disorder (BD), results are only few and preliminary.

AIM

the aim of the present study was to perform an exploratory investigation of the influence of personality traits as assessed by the Temperament and Character Inventory (TCI), on principal depression treatment outcomes (non remission, non response and resistance).

METHODS

743 mood disorders patients (455 MDD (61.24%) and 288 BD (38.76%)) were recruited in the context of 6 European studies. Generalized logit models were performed to test the effects of TCI dimensions on treatment outcomes, considering possible confounders such as age, gender and education. Positive results were controlled for comorbidities (anxiety and substance use disorders) as well.

RESULTS

MDD Non-Remitters showed high Harm Avoidance (HA) and Self Transcendence (ST) (p = 0.0004, d = 0.40; p = 0.007, d = 0.36 respectively) and low Persistence (P) and Self Directedness (SD) (p = 0.05; d = 0.18; p = 0.002, d = 0.40, respectively); MDD Non-Responders showed a slightly different profile with high HA and low Reward Dependence (RD) and SD; finally, MDD Resistants showed low RD, P and Cooperativeness (C). In BD patients, only higher HA in non response was observed.

LIMITATIONS

the retrospective cross-sectional design, the TCI assessment regardless of the mood state and the small number of bipolar patients represent the main limitations.

CONCLUSION

specific TCI personality traits are associated with depression treatment outcome in MDD patients. The inclusion of such personality traits, together with other socio-demographic and clinical predictors, could ameliorate the accuracy of the prediction models available to date.

Definition of treatment-resistant depression - Asia Pacific perspectives

BACKGROUND

The lack of uniformity in the definition of treatment resistant depression (TRD) within the Asia-Pacific (APAC) region may have implications for patient management. We aimed to characterize the most commonly used TRD definition in selected APAC countries.

METHODS

A systematic literature review of TRD definitions in APAC countries was conducted in Medline and Embase (2010-2016) and conference proceedings (2014 and 2016). TRD guidelines (APAC, Europe regional, US, or international) were also searched. An expert-panel explored APAC nuances in TRD definitions to achieve consensus for a regional-level definition.

RESULTS

Ten guidelines and 89 studies qualified for study inclusion. Among the studies, variations were observed in definitions regarding: number of antidepressants failed (range: ≥1 to ≥3), classes of antidepressants (same or different; 59% did not specify class), duration of previous treatments (range: 4-12 weeks), dosage adequacy, and consideration of adherence (yes/no; 88% of studies did not consider adherence). No TRD-specific guidelines were identified. The emerging consensus from the literature review and panel discussion was that TRD is most commonly defined as failure to ≥2 antidepressant therapies given at adequate doses, for 6-8 weeks during a major depressive episode.

LIMITATIONS

Few studies provided definitions of TRD used in daily clinical practice, and a limited number of countries were represented in the included studies and expert panel.

CONCLUSION

Attaining consensus on TRD definition may promote accurate, and possibly early detection of patients with TRD to enable appropriate intervention that may impact patient outcomes and quality of life.

Social Anxiety, Depression and Close Relationship: Intra and Inter-Personal Perceptions of Social-Rank and Affiliation

The present study investigated the associations between social anxiety (SA) and depression on the one hand, and intra- and interpersonal perceptions within a friendship relationship on the other. Evolutionary theories suggest that SA is associated with impairment in the social-rank system. Recent studies suggest that depression is associated with impairment in the affiliation system. We examined whether these impairments are manifested in the positivity and accuracy of (a) self-perception; (b) meta-perception (beliefs about how the other perceives the self); and (c) other-perception (evaluations of the friend). Pairs of same-sex friends (n = 50) completed rankings pertaining to these perceptions on general, social-rank, and affiliation traits. Higher levels of SA were associated with lower self-perception positivity, lower meta-perception positivity, and lower accuracy in the social-rank domain. Moreover, higher levels of SA were associated with perceiving the friend as higher on social-rank, regardless of the friend's self-rated traits. Higher levels of depression were associated with lower affiliation and social-rank self-perception positivity, and with lower accuracy in the domain of affiliation. Our findings broaden current conceptualizations of SA and depression and highlight the importance of understanding these disorders through the lens of interpersonal relationships.

Predictive modeling of treatment resistant depression using data from STAR*D and an independent clinical study

Identification of risk factors of treatment resistance may be useful to guide treatment selection, avoid inefficient trial-and-error, and improve major depressive disorder (MDD) care. We extended the work in predictive modeling of treatment resistant depression (TRD) via partition of the data from the Sequenced Treatment Alternatives to Relieve Depression (STAR*D) cohort into a training and a testing dataset. We also included data from a small yet completely independent cohort RIS-INT-93 as an external test dataset. We used features from enrollment and level 1 treatment (up to week 2 response only) of STAR*D to explore the feature space comprehensively and applied machine learning methods to model TRD outcome at level 2. For TRD defined using QIDS-C₁₆ remission criteria, multiple machine learning models were internally cross-validated in the STAR*D training dataset and externally validated in both the STAR*D testing dataset and RIS-INT-93 independent dataset with an area under the receiver operating characteristic curve (AUC) of 0.70–0.78 and 0.72–0.77, respectively. The upper bound for the AUC achievable with the full set of features could be as high as 0.78 in the STAR*D testing dataset. Model developed using top 30 features identified using feature selection technique (k-means clustering followed by χ² test) achieved an AUC of 0.77 in the STAR*D testing dataset. In addition, the model developed using overlapping features between STAR*D and RIS-INT-93, achieved an AUC of > 0.70 in both the STAR*D testing and RIS-INT-93 datasets. Among all the features explored in STAR*D and RIS-INT-93 datasets, the most important feature was early or initial treatment response or symptom severity at week 2. These results indicate that prediction of TRD prior to undergoing a second round of antidepressant treatment could be feasible even in the absence of biomarker data.

Indicators of patients with major depressive disorder in need of highly specialized care: A systematic review

Objectives

Early identification of patients with major depressive disorder (MDD) that cannot be managed by secondary mental health services and who require highly specialized mental healthcare could enhance need-based patient stratification. This, in turn, may reduce the number of treatment steps needed to achieve and sustain an adequate treatment response. The development of a valid tool to identify patients with MDD in need of highly specialized care is hampered by the lack of a comprehensive understanding of indicators that distinguish patients with and without a need for highly specialized MDD care. The aim of this study, therefore, was to systematically review studies on indicators of patients with MDD likely in need of highly specialized care.

Methods

A structured literature search was performed on the PubMed and PsycINFO databases following PRISMA guidelines. Two reviewers independently assessed study eligibility and determined the quality of the identified studies. Three reviewers independently executed data extraction by using a pre-piloted, standardized extraction form. The resulting indicators were grouped by topical similarity, creating a concise summary of the findings.

Results

The systematic search of all databases yielded a total of 7,360 references, of which sixteen were eligible for inclusion. The sixteen papers yielded a total of 48 unique indicators. Overall, a more pronounced depression severity, a younger age of onset, a history of prior poor treatment response, psychiatric comorbidity, somatic comorbidity, childhood trauma, psychosocial impairment, older age, and a socioeconomically disadvantaged status were found to be associated with proxies of need for highly specialized MDD care.

Conclusions

Several indicators are associated with the need for highly specialized MDD care. These indicators provide easily measurable factors that may serve as a starting point for the development of a valid tool to identify patients with MDD in need of highly specialized care.

Challenging Treatment-Resistant Major Depressive Disorder: A Roadmap for Improved Therapeutics

Major depressive disorder (MDD) is associated with a significant burden and costs to the society. As remission of depressive symptoms is achieved in only one-third of the MDD patients after the first antidepressant trial, unsuccessful treatments contribute largely to the observed suffering and social costs of MDD. The present article provides a summary of the therapeutic strategies that have been tested for treatment-resistant depression (TRD). A computerized search on MedLine/PubMed database from 1975 to September 2014 was performed, using the keywords “treatment-resistant depression”, “major depressive disorder”, “adjunctive”, “refractory” and “augmentation”. From the 581 articles retrieved, two authors selected 79 papers. A manual searching further considered relevant articles of the reference lists. The evidence found supports adding or switching to another antidepressant from a different class is an effective strategy in more severe MDD after failure to an initial antidepressant trial. Also, in subjects resistant to two or more classes of antidepressants, some augmentation strategies and antidepressant combinations should be considered, although the overall response and remission rates are relatively low, except for fast acting glutamatergic modulators. The wide range of available treatments for TRD reflects the complexity of MDD, which does not underlie diverse key features of the disorder. Larger and well-designed studies applying dimensional approaches to measure efficacy and effectiveness are warranted.

Personality Disorder in Adult Attention-Deficit/Hyperactivity Disorder: Attrition and Change During Long-term Treatment

Personality disorders (PDs) are commonly found in adults with attention-deficit/hyperactivity disorder (ADHD) and are associated with increased ADHD symptoms and psychosocial impairment. To assess the impact of PDs or personality traits on retention rates in ADHD trials and whether treating ADHD affects the expression of PD, data were analyzed from 2 methylphenidate trials. Assessment of PDs and personality traits included using the Wisconsin Personality Disorders Inventory IV and the Structured Clinical Interview for Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition Personality Disorders. Attention-deficit/hyperactivity disorder symptoms were evaluated using the Wender-Reimherr Adult Attention Deficit Disorder Scale. Major findings were that subjects with cluster A, cluster B, passive-aggressive, or more than 1 PD showed more attrition. Subjects dropping out also had more schizoid and narcissistic traits. Attention-deficit/hyperactivity disorder symptoms (p < 0.001) and all personality traits (range, p = 0.03 to p = 0.001) improved, but there was almost no correlation between changes on these 2 measures. Conversely, of 11 Wisconsin Personality Disorders Inventory IV items that improved most, 8 resembled ADHD or oppositional defiant disorder symptoms.

Use of the Temperament and Character Inventory to Predict Response to Repetitive Transcranial Magnetic Stimulation for Major Depression

OBJECTIVE

The goal of this study was to investigate the utility of the Temperament and Character Inventory (TCI) in predicting antidepressant response to repetitive transcranial magnetic stimulation (rTMS).

BACKGROUND

Although rTMS of the dorsolateral prefrontal cortex is an established antidepressant treatment, little is known about predictors of response. The TCI measures multiple personality dimensions (harm avoidance, novelty seeking, reward dependence, persistence, self-directedness, self-transcendence, and cooperativeness), some of which have predicted response to pharmacotherapy and cognitive-behavioral therapy. A previous study suggested a possible association between self-directedness and response to rTMS in melancholic depression, although this was limited by the fact that melancholic depression is associated with a limited range of TCI profiles.

METHODS

Nineteen patients with a major depressive episode completed the TCI before a clinical course of rTMS over the dorsolateral prefrontal cortex. Treatment response was defined as ≥50% decrease in scores on the Hamilton Rating Scale for Depression (Ham-D). Baseline scores on each TCI dimension were compared between responders and nonresponders through analysis of variance. Pearson correlations were also calculated for temperament/character scores in comparison with percentage improvement in Ham-D scores.

RESULTS

Eleven of the 19 patients responded to rTMS. T-scores for persistence were significantly higher in responders than in nonresponders (P=0.022). Linear regression revealed a correlation between persistence scores and percentage improvement in Ham-D scores.

CONCLUSIONS

Higher persistence scores predicted antidepressant response to rTMS. This may be explained by rTMS-induced enhancement of cortical excitability, which has been found to be decreased in patients with high persistence. Personality assessment that includes measurement of TCI persistence may be a useful component of precision medicine initiatives in rTMS for depression.

Pharmacological approaches to the challenge of treatment-resistant depression

Although monoaminergic antidepressants revolutionized the treatment of Major Depressive Disorder (MDD) over a half-century ago, approximately one third of depressed patients experience treatment-resistant depression (TRD). Such patients account for a disproportionately large burden of disease, as evidenced by increased disability, cost, human suffering, and suicide. This review addresses the definition, causes, evaluation, and treatment of unipolar TRD, as well as the major treatment strategies, including optimization, augmentation, combination, and switch therapies. Evidence for these options, as outlined in this review, is mainly focused on large-scale trials or meta-analyses. Finally, we briefly review emerging targets for antidepressant drug discovery and the novel effects of rapidly acting antidepressants, with a focus on ketamine.

The relevance of personality assessment in estimating the risk of onset and the outcome of major depressive disorder

In the past two decades, numerous studies have focused on the relationship between the psychobiological model of temperament and character and the development and evolution of major depressive disorder. This interest has been generated primarily because this particular model was developed as a tool for a comprehensive diagnosis of mental disorders. Such a diagnosis model, based on fewer diagnostic categories and a more phenomenological and person oriented approach seems to be supported by more recent research.

The aim of this paper was to review the latest developments in this area, but in the context of the initial development of the psychobiological model of temperament and character, i.e. as a tool for the comprehensive diagnosis of depressed individuals.

Data published so far supports the following observations: (1) high harm avoidance and low self-directedness are risk factors for the development of major depressive disorder, but further research is needed to clearly establish the role of the other dimensions or their facets as predictors for the development of a depressive episode; (2) although some evidence has been obtained so far regarding the use of harm avoidance, novelty seeking, reward dependence and cooperativeness in predicting treatment response in major depressive disorder, further research is needed to clarify and/or to replicate these findings; and (3) data on temperament and character dimensions related to relapse in major depressive disorder are insufficient, although some evidence has been brought to support the hypothesis that high harm avoidance scores, and low self-directedness and novelty seeking scores might serve as predictors; further prospective studies need to be carried out to establish their utility in this respect.

A meta-analysis of temperament and character dimensions in patients with mood disorders: Comparison to healthy controls and unaffected siblings

BACKGROUND

Cloninger's psychobiological model of personality has been extensively applied to subjects affected by mood disorders (MOOD). However, most studies are widely heterogeneous in terms of sample size, methods of assessment, and selection of participants.

METHODS

We conducted a systematic review of literature and a random effects meta-analysis of studies comparing at least two of the following groups: (a) adults with a primary MOOD diagnosis (Bipolar Disorder (BP) or major depressive disorder (MDD)), (b) their unaffected siblings (SIB) or (c) healthy subjects (HS), and reporting quantitative results from the Tridimensional Personality Questionnaire (TPQ) or the Temperament and Character Inventory (TCI). Subgroup, sensitivity and meta-regression analyses were also conducted.

RESULTS

High Harm Avoidance and low Self-Directedness were consistently associated with MOOD and SIB samples. BP was characterized by higher scores in Novelty Seeking and Self-Transcendence than HS, SIB and MDD. Age seemed to have a negative effect on Novelty Seeking and a positive effect on Harm Avoidance, Cooperativeness and Self-Transcendence. An euthymic mood state was associated with reduced Harm Avoidance, but increased Reward Dependence, Self-Directedness and Cooperativeness.

LIMITATIONS

The quality of the included studies varied and was relatively low. Moreover, publication bias and heterogeneity in the distribution of effect sizes may also have limited our results.

CONCLUSION

High Harm Avoidance and Low Self-Directedness may be trait markers for MOOD in general, while high Novelty Seeking and high Self-Transcendence may be specific to BP. Future studies are needed to disentangle the state-trait effect of each personality dimension.

Neural Implications of Psychotherapy, Pharmacotherapy, and Combined Treatment in Major Depressive Disorder

Numerous clinical trials have been conducted to determine the utility of antidepressant treatment (ADT), psychotherapy, and combined psycho-pharmaco-psychotherapy (PPPT) in treating major depressive disorder (MDD). While all approaches have shown benefit over placebo to varying degrees, the parallel neurophysiological mechanisms that underlie their efficacy have received little attention. The authors will review and discuss a growing body of literature that relates the factors of treatment selection and response to the principles of neuromodulation, with emphasis regarding how neuroimaging and other experimental data reinforce the need for personalized MDD treatment. This manuscript and its theoretical approaches were supported by conducting relevant literature searches of MEDLINE and PubMed electronic databases, prioritizing systemic reviews, and randomized clinical trials using selected MeSH terms. The authors conclude that ADT, psychotherapy, and PPPT all create potentially observable neurofunctional changes and argue that additive and synergistic potentiation of these effects in PPPT may produce more sustained symptom relief than with monotherapy alone.

Personality features, dissociation, self-stigma, hope, and the complex treatment of depressive disorder

OBJECTIVE

Identifying the predictors of response to psychiatric and psychotherapeutic treatments may be useful for increasing treatment efficacy in pharmacoresistant depressive patients. The goal of this study was to examine the influence of dissociation, hope, personality trait, and selected demographic factors in treatment response of this group of patients.

METHODS

Pharmacoresistant depressive inpatients were enrolled in the study. All patients completed Clinical Global Impression - both objective and subjective form (CGI), Beck Depression Inventory (BDI), and Beck Anxiety Inventory (BAI) at baseline and after 6 weeks of combined pharmacotherapy and psychotherapy (group cognitive-behavioral or group psychodynamic) treatment as an outcome measures. The Internalized Stigma of Mental Illness Scale (ISMI), Dissociative Experience Scale (DES), Adult Dispositional Hope Scale (ADHS), and Temperament and Character Inventory (TCI-R) were completed at the start of the treatment with the intention to find the predictors of treatment efficacy.

RESULTS

The study included 72 patients who were hospitalized for the pharmacoresistant major depression; 63 of them completed the study. The mean scores of BDI-II, BAI, subjCGI, and objCGI significantly decreased during the treatment. BDI-II relative change statistically significantly correlated with the total ISMI score, Discrimination Experience (ISMI subscale), and Harm Avoidance (TCI-R personality trait). According to stepwise regression, the strongest factors connected to BDI-II relative change were the duration of the disorder and Discrimination Experience (domain of ISMI). ObjCGI relative change significantly correlated with the level of dissociation (DES), the total ISMI score, hope in ADHS total score, and Self-Directedness (TCI-R). According to stepwise regression, the strongest factor connected to objCGI relative change was Discrimination Experience (domain of ISMI). The existence of comorbid personality disorder did not influence the treatment response.

CONCLUSION

According to the results of the present study, patients with pharmacoresistant depressive disorders, who have had more experience with discrimination because of their mental struggles, showed a poorer response to treatment.

Treatment-resistant depression: are animal models of depression fit for purpose?

BACKGROUND

Resistance to antidepressant drug treatment remains a major health problem. Animal models of depression are efficient in detecting effective treatments but have done little to increase the reach of antidepressant drugs. This may be because most animal models of depression target the reversal of stress-induced behavioural change, whereas treatment-resistant depression is typically associated with risk factors that predispose to the precipitation of depressive episodes by relatively low levels of stress. Therefore, the search for treatments for resistant depression may require models that incorporate predisposing factors leading to heightened stress responsiveness.

METHOD

Using a diathesis-stress framework, we review developmental, genetic and genomic models against four criteria: (i) increased sensitivity to stress precipitation of a depressive behavioural phenotype, (ii) resistance to chronic treatment with conventional antidepressants, (iii) a good response to novel modes of antidepressant treatment (e.g. ketamine; deep brain stimulation) that are reported to be effective in treatment-resistant depression and (iv) a parallel to a known clinical risk factor.

RESULTS

We identify 18 models that may have some potential. All require further validation. Currently, the most promising are the Wistar-Kyoto (WKY) and congenital learned helplessness (cLH) rat strains, the high anxiety behaviour (HAB) mouse strain and the CB1 receptor knockout and OCT2 null mutant mouse strains.

CONCLUSION

Further development is needed to validate models of antidepressant resistance that are fit for purpose. The criteria used in this review may provide a helpful framework to guide research in this area.

Pharmacological approaches to the challenge of treatment-resistant depression

Although monoaminergic antidepressants revolutionized the treatment of Major Depressive Disorder (MDD) over a half-century ago, approximately one third of depressed patients experience treatment-resistant depression (TRD). Such patients account for a disproportionately large burden of disease, as evidenced by increased disability, cost, human suffering, and suicide. This review addresses the definition, causes, evaluation, and treatment of unipolar TRD, as well as the major treatment strategies, including optimization, augmentation, combination, and switch therapies. Evidence for these options, as outlined in this review, is mainly focused on large-scale trials or meta-analyses. Finally, we briefly review emerging targets for antidepressant drug discovery and the novel effects of rapidly acting antidepressants, with a focus on ketamine.

Risk factors for treatment resistance in unipolar depression: a systematic review

BACKGROUND

Treatment resistant depression is a complex disorder and an important source of morbidity and mortality. Identification of risk factors of resistance may be useful to improve early recognition as well as treatment selection and prediction of outcome in patients with depression.

METHODS

The aim of this paper was to review the current status of knowledge regarding risk factors of treatment resistance in unipolar depression, in patients who failed to respond to at least two successive and adequate antidepressant treatments.

RESULTS

Systematic literature search yielded 8 publications exploring clinical and biological factors. Specific psychiatric comorbidities, psychosocial factors, clinical characteristics of the depressive episode and biological markers emerge as possible risk factor for treatment resistant depression.

LIMITATIONS

Due to the lack of objective definition and diagnostic criteria for treatment resistant depression, and the paucity of reports on risk factors, our review only summarized a small number of studies.

CONCLUSION

Future investigations of risk factors should help to improve the understanding of the mechanisms underlying resistance in mood disorders and contribute to improve their therapeutic management.

Personality in remitted major depressive disorder with single and recurrent episodes assessed with the Temperament and Character Inventory

AIM

Previous studies consistently reported increased harm avoidance (HA) assessed with the Temperament and Character Inventory (TCI) in patients with major depressive disorder (MDD). However, such findings may have been related with depression severity and number of depressive episodes. The aims of the present study were twofold: to examine TCI personality profile in remitted MDD (DSM-IV) patients and to compare TCI personality between MDD patients with single episode (SGL-MDD) and those with recurrent episodes (REC-MDD) in order to elucidate personality profile associated with recurrence.

METHODS

TCI was administered to 86 outpatients with remitted SGL-MDD (12 male and 17 female patients; mean age 43.2 ± 12.1 years) and REC-MDD (26 male and 31 female patients; 40.3 ± 11.6 years), and 529 healthy controls (225 men and 304 women; 43.4 ± 15.5 years), matched for age, sex and education years. Logistic regression analyses were performed in which single/recurrent episodes of depression were the dependent variable and age, sex, age of onset, family history of psychiatric disease and TCI scores were entered as possible predictors.

RESULTS

The remitted MDD patients had significantly higher scores on HA (P < 0.001) and lower scores on self-directedness (P < 0.001), compared with the controls. HA (P = 0.03), its subscore, fatigability (P = 0.03), and family history of psychiatric disease were found to be positive predictors for recurrence.

CONCLUSION

There are differences in personality profile between remitted MDD patients and controls, and between remitted REC-MDD and SGL-MDD patients, suggesting that they are trait markers. HA and fatigability might be useful to assess risk for recurrence of depression.

The structural equation analysis of childhood abuse, adult stressful life events, and temperaments in major depressive disorders and their influence on refractoriness

BACKGROUND

Previous studies have shown the interaction between heredity and childhood stress or life events on the pathogenesis of a major depressive disorder (MDD). In this study, we tested our hypothesis that childhood abuse, affective temperaments, and adult stressful life events interact and influence the diagnosis of MDD.

PATIENTS AND METHODS

A total of 170 healthy controls and 98 MDD patients were studied using the following self-administered questionnaire surveys: the Patient Health Questionnaire-9 (PHQ-9), the Life Experiences Survey, the Temperament Evaluation of the Memphis, Pisa, Paris, and San Diego Autoquestionnaire, and the Child Abuse and Trauma Scale (CATS). The data were analyzed with univariate analysis, multivariable analysis, and structural equation modeling.

RESULTS

The neglect scores of the CATS indirectly predicted the diagnosis of MDD through cyclothymic and anxious temperament scores of the Temperament Evaluation of the Memphis, Pisa, Paris, and San Diego Autoquestionnaire in the structural equation modeling. Two temperaments - cyclothymic and anxious - directly predicted the diagnosis of MDD. The validity of this result was supported by the results of the stepwise multivariate logistic regression analysis as follows: three factors - neglect, cyclothymic, and anxious temperaments - were significant predictors of MDD. Neglect and the total CATS scores were also predictors of remission vs treatment-resistance in MDD patients independently of depressive symptoms.

LIMITATIONS

The sample size was small for the comparison between the remission and treatment-resistant groups in MDD patients in multivariable analysis.

CONCLUSION

This study suggests that childhood abuse, especially neglect, indirectly predicted the diagnosis of MDD through increased affective temperaments. The important role as a mediator of affective temperaments in the effect of childhood abuse on MDD was suggested.

Personality traits as predictors for the outcome of lithium augmentation in treatment-resistant depression

The NEO Personality Inventory-Revised (NEO) and the Temperament and Character Inventory (TCI) were administered to patients with treatment-resistant depression (n=21) before lithium augmentation. Analysis showed that the poor outcome group (n=11) had lower openness scores on the NEO, and lower cooperativeness scores on the TCI compared with the good outcome group (n=10). These findings may be predictors of poor responsiveness to lithium augmentation in the treatment of antidepressant-resistant depression.

A study of remitted and treatment-resistant depression using MMPI and including pessimism and optimism scales

Background

The psychological aspects of treatment-resistant and remitted depression are not well documented.

Methods

We administered the Minnesota Multiphasic Personality Inventory (MMPI) to patients with treatment-resistant depression (n = 34), remitted depression (n = 25), acute depression (n = 21), and healthy controls (n = 64). Pessimism and optimism were also evaluated by MMPI.

Results

ANOVA and post-hoc tests demonstrated that patients with treatment-resistant and acute depression showed similarly high scores for frequent scale (F), hypochondriasis, depression, conversion hysteria, psychopathic device, paranoia, psychasthenia and schizophrenia on the MMPI compared with normal controls. Patients with treatment-resistant depression, but not acute depression registered high on the scale for cannot say answer. Using Student's t-test, patients with remitted depression registered higher on depression and social introversion scales, compared with normal controls. For pessimism and optimism, patients with treatment-resistant depression demonstrated similar changes to acutely depressed patients. Remitted depression patients showed lower optimism than normal controls by Student's t-test, even though these patients were deemed recovered from depression using HAM-D.

Conclusions

The patients with remitted depression and treatment-resistant depression showed subtle alterations on the MMPI, which may explain the hidden psychological features in these cohorts.

Personality traits associated with suicidal behaviors in patients with depression: the CRESCEND study

The aim of the current study was to identify personality traits associated with suicidal behavior in patients with depression. Of the 1183 patients screened for an observational cohort study of depression, 334 (28.2%) who completed the Temperament and Character Inventory (TCI) were included in these analyses. To minimize the effect of current mood state, the TCI was performed 12 weeks after initiation of treatment, and we adjusted for the severity of depression. Of the 344 participants, 59 had a lifetime history of at least one suicide attempt, 37 had a lifetime history of multiple suicide attempts, and 5 attempted suicide during the 12-week study period. At baseline, patients with a lifetime history of at least one suicide attempt, a lifetime history of multiple suicide attempts, and a suicide attempt during the study period expressed more serious current suicidal ideation than did those without such a history, despite the absence of differences among the groups in the severity of depressive and anxiety symptoms. Of the seven personality scales of the TCI, lower scores on the self-directedness scale of the character dimension were associated with a history of at least one suicide attempt (OR [95% CI], 0.91 [0.87-0.96]; p<0.001), a history of multiple suicide attempts (0.91 [0.86-0.97]; p=0.003), and suicide attempts during study period (0.80 [0.69-0.94]; p=0.006). These findings suggest that depressed patients with a history of suicidal behavior differ from non-attempters with regard to personality traits, especially the character dimension of self-directedness. It is noteworthy that this result emerged after controlling for the effect of current mood state.

Low openness on the revised NEO personality inventory as a risk factor for treatment-resistant depression

Background

Recently, we reported that low reward dependence, and to a lesser extent, low cooperativeness in the Temperature and Character Inventory (TCI) may be risk factors for treatment-resistant depression. Here, we analyzed additional psychological traits in these patients.

Methods

We administered Costa and McCrae's five-factor model personality inventory, NEO Personality Inventory-Revised (NEO-PI-R), to antidepressant-treatment resistant depressed patients (n = 35), remitted depressed patients (n = 27), and healthy controls (n = 66). We also evaluated the relationships between scores on NEO and TCI, using the same cohort of patients with treatment-resistant depression, as our previous study.

Results

Patients with treatment-resistant depression showed high scores for neuroticism, low scores for extraversion, openness and conscientiousness, without changes in agreeableness, on the NEO. However, patients in remitted depression showed no significant scores on NEO. Patients with treatment-resistant depression and low openness on NEO showed positive relationships with reward dependence and cooperativeness on the TCI.

Conclusions

Many studies have reported that depressed patients show high neuroticism, low extraversion and low conscientiousness on the NEO. Our study highlights low openness on the NEO, as a risk mediator in treatment-resistant depression. This newly identified trait should be included as a risk factor in treatment-resistant depression.