Determinants of Treatment-Resistant Depression: The Salience of Benzodiazepines

In-silico testing of new pharmacology for restoring inhibition and human cortical function in depression

Reduced inhibition by somatostatin-expressing interneurons is associated with depression. Administration of positive allosteric modulators of α5 subunit-containing GABAA receptor (α5-PAM) that selectively target this lost inhibition exhibit antidepressant and pro-cognitive effects in rodent models of chronic stress. However, the functional effects of α5-PAM on the human brain in vivo are unknown, and currently cannot be assessed experimentally. We modeled the effects of α5-PAM on tonic inhibition as measured in human neurons, and tested in silico α5-PAM effects on detailed models of human cortical microcircuits in health and depression. We found that α5-PAM effectively recovered impaired cortical processing as quantified by stimulus detection metrics, and also recovered the power spectral density profile of the microcircuit EEG signals. We performed an α5-PAM dose-response and identified simulated EEG biomarker candidates. Our results serve to de-risk and facilitate α5-PAM translation and provide biomarkers in non-invasive brain signals for monitoring target engagement and drug efficacy.

Intravenous ketamine for benzodiazepine deprescription and withdrawal management in treatment-resistant depression: a preliminary report

We present the first evidence that sub-anesthetic ketamine infusions for treatment resistant depression (TRD) may facilitate deprescription of long-term benzodiazepine/z-drugs (BZDRs). Long-term BZDR prescriptions are potentially harmful yet common, partly because of challenging withdrawal symptoms. Few pharmacological interventions have evidence for facilitating BZDR discontinuation, and none in patients actively suffering from TRD. In this ambi-directional cohort study, discontinuation of long-term (>6 month) BZDRs was attempted in 22 patients with severe unipolar or bipolar TRD receiving a course of six subanesthetic ketamine infusions over four weeks. We investigated the rates of successful BZDRs deprescription, trajectories of acute psychological withdrawal symptoms, and subsequent BZDRs abstinence during a mean follow-up of 1 year (primary outcome). Clinically significant deteriorations in depression, anxiety, sleep, and/or suicidality during the acute BZDR discontinuation phase were measured by repeated standardized scales and analyzed by latent growth curve models and percent correct classification analysis. Of the 22 eligible patients, all enrolled in this study and 91% (20/22) successfully discontinued all BZDRs by the end of the 4-week intervention, confirmed by urinary analyses. Less than 25% of discontinuers experienced any significant worsening of anxiety, depression, sleep difficulties, or suicidality during treatment. During follow-up (mean [range] duration, 12 [3-24] months), 64% (14/22) of patients remained abstinent from any BZDRs. These preliminary results suggest that ketamine infusions for TRD may facilitate the deprescription of BZDRs, even in patients with active depressive symptoms and significant comorbidity. Further investigation is warranted into this potential novel application of ketamine.

Recommendations of the treatment-resistant depression expert center network for promoting tobacco smoking cessation based on the results from the real-world FACE-TRD national cohort

BACKGROUND

Tobacco smoking has been associated with suicide, impulsivity and depression in non-clinical populations with differences across sexes.

OBJECTIVE

To determine the role of tobacco smoking in Treatment-Resistant Depression (TRD) according to sex in a precision-medicine approach.

METHOD

The FACE-TRD cohort is a national cohort of TRD patients recruited in 13 resistant depression expert centers between 2014 and 2021 and followed-up at 6 months. A standardized one-day long comprehensive battery was carried out, including trained-clinician and patient-reported outcomes, and patients were reevaluated at 6 months on their smoking and psychiatric hospitalization outcomes.

RESULTS

355 TRD participants were included (222 women). The smoking rate was much higher in TRD women compared to the French general population (34% vs 24%) while it was comparable for men (approximately 29%). In multivariate analyses, compared to non-smoking women, female smokers had significantly increased number of lifetime psychiatric hospitalizations (standardized beta B = 0.232, p = 0.014) and electro-convulsive therapy (adjusted odds ratio (aOR) = 2.748, p = 0.005), increased suicidal ideations (aOR = 4.047, p = 0.031), history of suicide attempt (aOR = 1.994, p = 0.033), and increased impulsivity (B = 0.210, p = 0.006) and were more frequently treated by benzodiazepines (aOR = 1.848, p = 0.035) and third- or fourth-line TRD treatments (antipsychotics aOR = 2.270, p = 0.006, mood stabilizers aOR = 2.067 p = 0.044). Tobacco smoking at baseline was predictive of psychiatric hospitalization within 6 months in persistent smoking women (aOR = 2.636, p = 0.031). These results were not replicated in men, for whom tobacco smoking was only associated with increased clinician-rated and self-reported depressive symptoms (respectively B = 0.207, p = 0.022 and B = 0.184, p = 0.048). The smoking cessation rate at 6 months was higher in women than in men (12% vs. 7%). No patient was administered nicotine substitute or varenicline at the two timepoints.

INTERPRETATION

Combining these results and those of the literature, we recommend that active tobacco cessation should be promoted in TRD to improve depression, suicide and impulsivity especially in women. Female smokers appear as a specific population with heavier mental health outcomes that should be specifically addressed.

Novel drug developmental strategies for treatment-resistant depression

Major depressive disorder is a leading cause of disability worldwide. Because conventional therapies are ineffective in many patients, novel strategies are needed to overcome treatment‐resistant depression (TRD). Limiting factors of successful drug development in the last decades were the lack of (1) knowledge of pathophysiology, (2) translational animal models and (3) objective diagnostic biomarkers. Here, we review novel drug targets and drug candidates currently investigated in Phase I–III clinical trials. The most promising approaches are inhibition of glutamatergic neurotransmission by NMDA and mGlu₅ receptor antagonists, modulation of the opioidergic system by κ receptor antagonists, and hallucinogenic tryptamine derivates. The only registered drug for TRD is the NMDA receptor antagonist, S‐ketamine, but add‐on therapies with second‐generation antipsychotics, certain nutritive, anti‐inflammatory and neuroprotective agents seem to be effective. Currently, there is an intense research focus on large‐scale, high‐throughput omics and neuroimaging studies. These results might provide new insights into molecular mechanisms and potential novel therapeutic strategies.

Economic burden of treatment-resistant depression in privately insured US patients with co-occurring anxiety disorder and/or substance use disorder

OBJECTIVE

To assess the burden of treatment-resistant depression (TRD) among privately insured patients with anxiety disorder and/or substance use disorders (SUD).

METHODS

Adults <65 years old were identified in the Optum Health Care Solutions Inc. database (July 2009-March 2017). Among those with major depressive disorder (MDD) and antidepressant use, patients who initiated a third antidepressant (index date) after two regimens at adequate dose and duration were classified in the TRD cohort and patients without evidence of TRD were classified in the non-TRD MDD control cohort. The non-MDD control cohort comprised patients without MDD. In the non-TRD MDD and non-MDD cohorts, the index date was imputed to mimic the distribution of time in the TRD cohort from the first antidepressant to the index date or from the start of eligibility to the index date, respectively. Patients with <6 months of continuous insurance eligibility pre-/post-index, psychosis, schizophrenia, bipolar disorder and related conditions, dementia, and development disorders, and/or no baseline anxiety disorder and/or SUD were excluded. Patients with TRD were matched 1:1 to patients with non-TRD MDD and patients without MDD, based on exact matching factors (i.e. availability of work loss data) and propensity scores computed based on characteristics measured pre-index. Outcomes, including healthcare resource use (HRU) and costs, work productivity loss and related costs measured per patient per year ≤24 months post-index were compared between matched TRD, non-TRD MDD and non-MDD cohorts.

RESULTS

A total of 3166 patients were identified in the TRD cohort and matched to non-TRD MDD and non-MDD cohorts. Among patients with TRD (mean age 39 years, 60.5% female), 87.3% had an anxiety disorder, 24.1% had SUD. The TRD cohort had higher HRU vs non-TRD MDD and non-MDD cohorts: 0.32 vs 0.20 and 0.14 inpatient admissions, 0.91 vs 0.73 and 0.58 emergency department visits, and 23.8 vs 16.8 and 11.6 outpatient visits, respectively (all p < .01). The TRD cohort had higher healthcare costs ($16,674) vs non-TRD MDD ($10,945) and non-MDD ($6493) cohorts (all p < .01). Among patients with work loss data (N = 310/cohort), patients with TRD had more work loss days (54) and higher work loss-related costs ($13,674) vs patients with non-TRD MDD (32 days; $7131) and without MDD (17 days; $4798; all p < .01).

CONCLUSIONS

In patients with an anxiety disorder and/or SUD, TRD was associated with higher HRU, healthcare costs, work loss days and work loss-related costs.

Altered GABA-mediated information processing and cognitive dysfunctions in depression and other brain disorders

Cognitive dysfunctions, including impaired attention, learning, memory, planning and problem solving, occur in depressive episodes, often persist during remission, predict relapse, worsen with recurrent episodes, and are not treated by current antidepressants or other medications. Cognitive symptoms are also present in other psychiatric disorders, are a hallmark of aging, and define several late-life disorders, including Alzheimer's disease. This pervasive occurrence suggests either a non-specific outcome of a diseased brain, or a shared underlying pathology contributing to this symptom dimension. Recent findings suggest a role for altered GABAergic inhibition in cognitive symptoms. Cellular, molecular and biochemical studies in human subjects report changes affecting the gamma-amino butyric acid (GABA) system, specifically somatostatin-expressing (SST+) GABAergic interneurons, across brain disorders and during aging. SST+ neurons gate excitatory input onto pyramidal neurons within cortical microcircuits. Experimentally reducing the function of these neurons affects excitatory signal-to-noise ratio, reduces synchronized cellular and neural activity, and leads to cognitive dysfunctions. Conversely, augmenting SST+ cell post-synaptic α5-GABA-A receptor activity has pro-cognitive efficacy in stress and aging models. Together, this suggests that reduced signaling of the SST+ neuron/α5-GABA-A receptor pathway contributes to cognitive dysfunctions, and that it represents a novel therapeutic target for remediating mood and cognitive symptoms in depression, other psychiatric disorders and during aging.

Antianhedonic Effect of Repeated Ketamine Infusions in Patients With Treatment Resistant Depression

Anhedonia constitutes one of the main symptoms of depressive episode. It correlates with suicidality and significantly effects the quality of patient's lives. Available treatments are not sufficient against this group of symptoms. Ketamine is a novel, rapid acting strategy for treatment resistant depression. Here we report the change in symptoms of anhedonia measured by Snaith-Hamilton Pleasure Scale as an effect of eight ketamine infusions as an add-on treatment in 42 patients with treatment resistant depression. We also determined the effect of this change on the severity of depressive symptoms measured by Inventory for Depression Symptomatology-Self Report 30-Item (IDS-SR 30). We have observed statistically significant decrease in the level of anhedonia during ketamine treatment. After adjusting for potential confounders we have found that significant reduction in Snaith-Hamilton Pleasure Scale (SHAPS) after each infusion and 1 week post treatment was observed only among patients who did not use benzodiazepines. The reduction in symptoms of anhedonia mediates the antidepressive effect of ketamine. The results need replication in a larger randomized placebo controlled trial.

Understanding the effects of chronic benzodiazepine use in depression: a focus on neuropharmacology

Benzodiazepines are frequently prescribed on an ongoing basis to individuals with depression, mainly to alleviate anxiety or insomnia, despite current guideline recommendations that continuous use should not exceed 4 weeks. Currently, there are no efficacy trials published beyond 8 weeks. Several antidepressant trials demonstrate that the concomitant use of a benzodiazepine is associated with poorer depressive outcomes and functional status; however, it is unclear why this is the case. Patients with depression receiving a benzodiazepine may reflect a more ill or high anxiety group, although even within anxiety disorders, the use of a benzodiazepine is associated with poorer outcomes. The neuroadaptive consequences of long-term benzodiazepine use may be a factor underlying these findings. Chronic benzodiazepine use results in decreased gamma-aminobutyric acid and monoaminergic function, as well as interference with neurogenesis, which are all purported to play a role in antidepressant efficacy. This review will discuss the oppositional neuropharmacological interactions between chronic benzodiazepine use and antidepressant mechanism of action, which could result in reduced antidepressant efficacy and function in depression.

Substance use disorders and risk for treatment resistant depression: a population-based, nested case-control study

BACKGROUND AND AIMS

Treatment-resistant depression (TRD), defined as inadequate treatment response after at least two adequate treatment trials, is common among patients initiating antidepressant treatment. Current or previous substance use disorders (SUD) are common among patients with depression and often lead to worse treatment outcomes. However, in clinical studies, SUD have not been found to increase the risk for TRD. The aim of this study was to investigate the association between SUD and TRD.

DESIGN

Nested case-control study.

SETTING

Nation-wide governmental health-care registers in Sweden.

CASES AND CONTROLS

Data on prescribed drugs and diagnoses from specialized health care were used to establish a prospectively followed cohort of antidepressant initiators with depression (n = 121 669) from 2006 to 2014. Of these, 15 631 patients (13%) were defined as TRD cases, with at least three treatment trials within a single depressive episode. Each case with TRD was matched on socio-demographic data with five controls with depression.

MEASUREMENTS

Crude and adjusted odds ratios (aOR) with 95% confidence intervals (CI) estimated the association between TRD and SUD diagnosis and/or treatment in five different time intervals until the time for fulfillment of TRD definition for the case. The analysis was adjusted for clinical and socio-demographic covariates.

FINDINGS

Having any SUD during, or ≤ 180 days before start of, antidepressant treatment was associated with almost double the risk for TRD [≤ 180 days before: adjusted OR (aOR) = 1.86, CI = 1.70-2.05]. Increased risks for TRD were found ≤ 180 days before treatment start for the subcategories of sedative use (aOR = 2.37; 1.88-2.99), opioids (aOR = 2.02; 1.48-2.75), alcohol (aOR = 1.77; CI = 1.59-1.98) and combined substance use (aOR = 2.31; 1.87-2.99).

CONCLUSIONS

Recent or current substance use disorders is positively associated with treatment resistance among patients initiating treatment for depression.

Socio-demographic and clinical risk factors of treatment-resistant depression: A Danish population-based cohort study

BACKGROUND

Knowledge of risk factors of treatment-resistant depression (TRD) contributes to understand the underlying mechanisms and to identify patients at risk. However, there is still a lack of studies on how different risk factors associate with TRD. The objective of this study was to determine the independent association of several socio-demographic and clinical risk factors with TRD.

METHODS

194.074 patients with a first-time hospital contact for depression identified in the Danish National Patient Registry (DNPR) from 1996 through 2014 were followed for TRD for 12 months after diagnosis. Socio-demographic and clinical risk factors were identified in nation-wide registries. Data were analyzed using Cox Proportional Hazard Regression and Fine-Gray model for competing mortality risk.

RESULTS

Indicators of disease severity (recurrent depression (adjusted HR (aHR) 1.17 (1.14-1.20)), severity of depression (aHR 2.01 (1.95-2.08)), admission to a psychiatric ward (aHR 2.03 (1.96, 2.10)) were strong risk factors. Aged 65-84 (aHR 1.96 (1.83-2.10)), lost labor market affiliation ((aHR 1.12 (1.08, 1.16)), cohabiting (aHR 1.27 (1.23, 1.30)), comorbid anxiety (aHR 1.18 (1.10-1.27)), insomnia (aHR 1.27 (1.06-1.51)), migraine (aHR 1.42 (1.16-1.73)) and use of psychotropic drugs was also associated with higher rates of TRD.

LIMITATIONS

Information on drug use during hospitalization was not available. Information on rating scales could have provided a more precise assessment of symptom severity and treatment response.

CONCLUSIONS

Besides indicators of disease severity, other important risk factors associated with TRD are age, lost labor market affiliation, cohabiting with a partner as well as anxiety, insomnia, migraine and the use of psychotropic medications.

The Antidepressant Effect of Ketamine Is Dampened by Concomitant Benzodiazepine Medication

The rapid antidepressant effect of ketamine has become a breakthrough in the research and treatment of depression. Although predictive and modulating factors of the response to ketamine are broadly studied, little is known about optimal concurrent medication protocols. Concerning gamma-aminobutyric acid neurotransmission being a shared target for both ketamine and benzodiazepines (BZD), we evaluated the influence of BZD on the antidepressant effect of a single ketamine infusion in depressed patients. Data from 47 patients (27 females) with major depression (MADRS ≥ 20, ≥ 1 prior nonresponse to antidepressant treatment in current episode) who participated in two previous studies (EudraCT Number: 2009-010625-39 and 2013-000952-17) entered the analysis. All of the subjects were given an infusion of a subanesthetic dose of racemic ketamine (0.54 mg per kg) as an add-on medication to ongoing antidepressant treatment. Thirteen patients (28%) reached ≥ 50% reduction in MADRS within one week after ketamine administration. Nineteen (40%) patients took concomitant benzodiazepines on a daily basis. The doses of BZDs were significantly higher in nonresponders (p=0.007). ROC analysis distinguished responders from nonresponders by a criterion of >8mg of diazepam equivalent dose (DZ equivalent) with a sensitivity of 80% and a specificity of 85% (p<0.001). RM-ANOVA revealed a different time pattern of response to ketamine between the BZD+ (>8mg of DZ equivalent) and BZD- (≤8mg of DZ equivalent) groups, with a significantly worse outcome in BZD+ on day 3 (p=0.04) and day 7 (p=0.02). The results of the study indicate that concomitant benzodiazepine treatment in higher doses may attenuate ketamine's antidepressant effect. The pathophysiological, clinical and methodological implications of this finding should be considered in future research and ketamine treatment.

Beyond Prescriptions Monitoring Programs: The Importance of Having the Conversation about Benzodiazepine Use

: Internationally there is an escalation of prescription-related overdose deaths, particularly related to benzodiazepine use. As a result, many countries have implemented prescription monitoring programs (PMPs) to increase the regulation of benzodiazepine medications. PMPs centralize prescription data for prescribers and pharmacists and generate alerts to high-doses, risky combinations, or multiple prescribers with the aim to reduce inappropriate prescribing and subsequently the potential of patient harm. However, it has become clear that prescribers have been provided with minimal guidance and insufficient training to effectively integrate PMP information into their decision making around prescribing these medications. Accordingly, this paper discusses how PMPs have given rise to a range of unintended consequences in those who have been prescribed benzodiazepines (BDZs). Given that a gradual taper is generally required to mitigate withdrawal from BDZs, there are concerns that alerts from PMPs have resulted in BDZs being ceased abruptly, resulting in a range of unintended harms to patients. It is argued that best practice guidelines based upon a patient-centered framework of decision-making, need to be developed and implemented, in order to curtail the unintended consequences of PMPs. This paper outlines some key considerations when starting the conversation with patients about their BDZ use.

Treatment-resistant depression as risk factor for substance use disorders-a nation-wide register-based cohort study

BACKGROUND AND AIMS

Treatment-resistant depression (TRD) is common among patients with major depressive disorder (MDD). MDD may increase the risk for developing substance use disorders (SUD). The aim of this study was to investigate the risk for developing SUD among patients with TRD compared with other depressed patients.

DESIGN

Observational cohort study.

SETTING

Nation-wide governmental health registers in Sweden.

PARTICIPANTS

All patients aged 18-69 years with an MDD diagnosis in specialized health care who had received at least one antidepressant prescription during 2006-14 were identified. Patients with at least three treatment trials within a single depressive episode were classified with TRD.

MEASUREMENTS

Patients with TRD were compared with the whole MDD cohort regarding risk for obtaining a SUD diagnosis or medication using survival analyses adjusted for socio-demographics and comorbidities.

FINDINGS

Of 121 669 MDD patients, 13% were classified with TRD. Among the patients without any history of SUD, patients with TRD had a risk increase for any SUD both ≤ 1 and > 1 year after antidepressant initiation [> 1 year hazard ratio (HR) = 1.4; 95% confidence interval (CI) = 1.3-1.5]. Risks were elevated for the subcategories of opioid (HR = 1.9, 95% CI = 1.4-2.5) and sedative SUD (HR = 2.7, 95% CI = 2.2-3.2). Patients with a history of SUD had a risk increase for any SUD ≤ 1 year after start of treatment (HR = 1.2, 95% CI = 1.1-1.4), and both ≤ 1 year and > 1 year for sedative (> 1 year HR = 2.0, 95% CI = 1.3-3.0) and multiple substance SUD (HR = 1.9, 95% CI = 1.4-2.5).

CONCLUSIONS

Patients with treatment-resistant depression may be at greater risk for substance use disorders compared with other patients with major depressive disorder. Patterns may differ for patients with and without a history of substance use disorders, and for different categories of substance use disorder.

Novel Benzodiazepine-Like Ligands with Various Anxiolytic, Antidepressant, or Pro-Cognitive Profiles

Altered gamma-aminobutyric acid (GABA) function is consistently reported in psychiatric disorders, normal aging, and neurodegenerative disorders and reduced function of GABA interneurons is associated with both mood and cognitive symptoms. Benzodiazepines (BZ) have broad anxiolytic, but also sedative, anticonvulsant and amnesic effects, due to nonspecific GABA-A receptor (GABAA-R) targeting. Varying the profile of activity of BZs at GABAA-Rs is predicted to uncover additional therapeutic potential. We synthesized four novel imidazobenzodiazepine (IBZD) amide ligands and tested them for positive allosteric modulation at multiple α-GABAA-R (α-positive allosteric modulators), pharmacokinetic properties, as well as anxiolytic and antidepressant activities in adult mice. Efficacy at reversing stress-induced or age-related working memory deficits was assessed using a spontaneous alternation task. Diazepam (DZP) was used as a control. Three ligands (GL-II-73, GL-II-74, and GL-II-75) demonstrated adequate brain penetration and showed predictive anxiolytic and antidepressant efficacies. GL-II-73 and GL-II-75 significantly reversed stress-induced and age-related working memory deficits. In contrast, DZP displayed anxiolytic but no antidepressant effects or effects on working memory. We demonstrate distinct profiles of anxiolytic, antidepressant, and/or pro-cognitive activities of newly designed IBZD amide ligands, suggesting novel therapeutic potential for IBZD derivatives in depression and aging.

Frequent attenders in general medical practice in Italy: a preliminary report on clinical variables related to low functioning

BACKGROUND

Frequent attenders (FAs), defined as patients reporting a disproportionate number of visits to general practitioners (GPs), may represent up to one-third of GP patients responsible for a high burden of care not always justified by the severity of the medical condition. The aim of this study was to explore sociodemographic and clinical characteristics of FAs of GP in Italy with particular attention to functional impairment.

METHODS

A total sample of 75 FAs (defined as individuals who had consulted GPs 15 times or more during 2015) of GPs of three primary care centers (Pisa, Livorno, and Lucca) in Italy were enrolled and assessed by sociodemographic scale, Structured Clinical Interview for DSM-5 (SCID-5), global functioning (Global Assessment of Functioning [GAF]), illness behavior and perceived health (Illness Behavior Inventory), and somatic comorbidity (Cumulative Illness Rating Scale).

RESULTS

Most of the sample were females, middle aged, married, or cohabiting, with low levels of education. One-third of FAs was low functioning (LF; GAF score <70), with no differences in the sociodemographic variables. Approximately 70.3% of the patients reported a current SCID diagnosis, in particular, major depressive disorder, somatic symptom disorders, and panic disorder, all being more frequent in LF patients. Half of the patients were taking a psychopharmacological therapy, mostly benzodiazepines (BDZs).

CONCLUSION

Most FAs were female with current medical disorders, and LF. All claimed to be worried about their own health and perceived themselves as more impaired also regarding the health perception and social role. LF patients were, or had been more likely to be under psychopharmacological treatment. FAs seem to constitute a special population that should be carefully evaluated for mental disorders and appropriate treatment.

[Use and misuse of benzodiazepines in patients with psychiatric disorders]

The psychiatric patients are not only particularly exposed to benzodiazepines; they may also be more vulnerable to their side effects than general population. Benzodiazepines are frequently misused in psychiatric patients in terms of duration, dose and number of concomitant medications. There is no evidence that benzodiazepines are effective against most psychiatric disorders, including depression and suicidal risk. Several studies have shown associations between benzodiazepine use and depression worsening, increased disinhibition, suicide risk, anxiety, aggression, and even mortality in patients with psychiatric disorders. Despite the common use of benzodiazepine drugs by clinicians, large and methodologically sound studies are lacking to document the patterns of benzodiazepine use in populations with psychiatric disorders and their specific risks in these patients. It is not known whether it is legitimate to apply the good practice recommendations for benzodiazepines in patients with severe psychiatric disorders.

Prevalence of and pathways to benzodiazepine use in Brazil: the role of depression, sleep, and sedentary lifestyle

Objective:

This study aimed to determine the prevalence of benzodiazepine (BZD) use in Brazil and to investigate the direct and indirect effects of alcohol consumption, sedentary lifestyle (SL), depressive symptoms (DS), and sleep dissatisfaction (SD) on BZD use.

Methods:

The Second Brazilian Alcohol and Drugs Survey (II BNADS) used stratified cluster probabilistic sampling to select 4,607 individuals aged 14 years and older from the Brazilian household population.

Results:

The lifetime and 12-month prevalence of BZD use was 9.8 and 6.1%, respectively. Older participants (age 40 and older) and women had higher rates. Alcohol use disorder, DS, and SD were significantly more prevalent in BZD users. The parallel multiple mediator model showed a positive direct effect of alcohol consumption on BZD use, with significant positive indirect effects of SL, SD, and DS as simultaneous mediators leading to higher BZD intake. Other statistically significant indirect pathways were DS alone, SD alone, and all of the above except SL.

Conclusion:

The prevalence of BZD use in Brazil is high compared to that of other countries. Knowledge of the main risk factors and pathways to consumption can guide prevention initiatives and underlie the development of better tailored and effective treatment strategies.

Mortality in treatment-resistant unipolar depression: A register-based cohort study in Sweden

BACKGROUND

The impact of treatment resistant depression (TRD) on mortality is not established.

METHODS

Using Swedish national registers, 118,774 patients between 18-69 years of age who had been prescribed an antidepressant and been diagnosed with depression in specialized care were identified. Patients with at least two additional treatment trials during the same depressive episode were classified as having TRD. Data on the covariates of sex, age, history of depression, self-harm, substance use disorders, and other psychiatric and somatic comorbidities was also used. Relative risks comparing TRD patients with other depressed patients were calculated as hazard ratios (HR) for all-cause mortality and for external and non-external causes of death, as well as excess mortality rate ratios (EMRR), with 95% confidence intervals (CI).

RESULTS

In total 15,013 patients (13%) were classified with TRD. Adjusted HR for all-cause mortality was 1.35 (95% CI 1.21-1.50). Mortality from external causes (including suicides and accidents) was markedly higher in TRD patients than in other depressed patients (HR 1.97; 1.69-2.29), while mortality from non-external causes was similar. The adjusted EMRR was 1.52 (1.31-1.76), highest among patients 18-29 years old (EMRR 2.03; 1.31-1.76) and patients without somatic comorbidity (EMRR 1.99; 1.63-2.43).

LIMITATIONS

Severity of depression and adherence to treatment were not available in the data.

CONCLUSIONS

Patients with TRD may have an increased all-cause mortality compared to other depressed patients, mainly for external causes of death. The relative mortality is highest among young and physically healthy patients.

Predictors of benzodiazepine use in a transdiagnostic sample of panic disorder, social anxiety disorder, and obsessive-compulsive disorder patients

We investigated the rates of current and past benzodiazepine (BZD) use in a sample of 102 subjects attending specialized anxiety disorder clinics, including panic disorder (PD; N = 36), social anxiety disorder (SAD; N = 28) and obsessive-compulsive disorder (OCD; N = 38) patients. Almost 56% of the entire sample was using BZDs at the moment of the assessment, and 74.5% described having used them at some point during their lifetimes. The duration of psychiatric treatment and a lifetime history of PD, but not any other "transdiagnostic" measure of severity (such as the Panic and Agoraphobia Scale, the Social Phobia Inventory, the Dimensional Obsessive-Compulsive Scale, the Anxiety Sensitivity Index-36, and the Beck Inventories) were independent risk factors for current prescription of BZDs. Patients who continued to use BZDs differed from patients who stopped them by being older (both currently and when firstly seen in the clinic), by having a later age at onset of their most significant anxiety disorder, by being more agoraphobic/avoidant, and by believing to be less capable of stopping their BZDs for the fear of not being able to sleep.

Clinical Characteristics Associated With Treatment-Resistant Bipolar Disorder

There has been limited consideration and empirical studies on treatment-resistant bipolar disorder (TRBD). This exploratory study was designed to identify factors contributing to TRBD in patients with a bipolar (I or II) disorder. Patients were categorized with "low," "medium," or "high" levels of treatment resistance based on a) the total number of psychiatric medications received and, for a second analysis, b) the number of mood stabilizer medications received. The study identified a number of factors associated with TRBD, such as being female and older and having an older age at illness onset, a higher incidences of family depression, less likelihood of being in paid employment, a higher number of lifetime stressors, medical conditions and comorbid anxiety disorders, a different personality and temperament profile, and more regular use of benzodiazepines. There were few factors associated with TRBD when defined by number of mood stabilizers trialed. Potential explanations for these findings were explored.