A review of the neurobiological underpinning of comorbid substance use and mood disorders

Comparing Transdiagnostic Risk Factors: Predicting Emergence of Significant Depressive, Anxiety, and Substance Abuse Symptoms Among Juvenile Delinquents

In a 7-year 11-wave study of low-SES adolescents (N = 856, age = 15.98), we compared multiple well-established transdiagnostic risk factors as predictors of first incidence of significant depressive, anxiety, and substance abuse symptoms across the transition from adolescence to adulthood. Risk factors included negative emotionality, emotion regulation ability, social support, gender, history of trauma, parental histories of substance abuse, parental mental health, and socioeconomic status. Machine learning models revealed that negative emotionality was the most important predictor of both depression and anxiety, and emotion regulation ability was the most important predictor of future significant substance abuse. These findings highlight the critical role that dysregulated emotion may play in the development of some of the most prevalent forms of mental illness.

Comorbid substance use disorder, major depression, and associated disability in a nationally representative sample

BACKGROUND

Major depressive disorders (MDD) and substance use disorders (SUDs) are commonly linked to disability, but there is a lack of research on the risk of disability among individuals who have both SUDs and MD in the general population. This study aimed to investigate the associated risk of disability in people with comorbid SUDs- specifically cannabis use disorder, alcohol use disorder, other drug (except cannabis) use disorder, and a major depressive episode using a nationally representative sample.

METHODS

The 2012 Canadian Community Health Survey- Mental Health (CCHS-MH) data were analyzed using multilevel logistic regression models. The survey included a nationally representative sample of Canadians aged 15 years and older (n = 25,113) residing in the ten Canadian provinces from January to December 2012. The diagnoses of major depressive episodes (MDE) and the SUDs were derived from the DSM-IV diagnostic criteria using a modified WHO-CIDI instrument, while disability was assessed using the World Health Organization Disability Assessment Score (WHODAS) 2.0.

RESULTS

The strongest predictor of disability was found to be comorbidity. Individuals diagnosed with both a SUD and MDE were 4 to 9 times more likely to experience disability, depending on the substance used, compared to those without either diagnosis.

LIMITATIONS

The study's cross-sectional design limits causal inferences.

CONCLUSIONS

Our research discovered that individuals who have both SUD and MDE are at a significantly higher risk of experiencing disability. This highlights the importance of integrating mental health and addiction services to mitigate the risk of disability and improve overall treatment outcomes.

Electrophysiological biomarkers in dual pathology

INTRODUCTION

The co-occurrence of substance use disorder with at least one other mental disorder is called dual pathology, which in turn is characterised by heterogeneous symptoms that are difficult to diagnose and have a poor response to treatment. For this reason, the identification and validation of biomarkers is necessary. Within this group, possible electroencephalographic biomarkers have been reported to be useful in diagnosis, treatment and follow-up, both in neuropsychiatric conditions and in substance use disorders. This article aims to review the existing literature on electroencephalographic biomarkers in dual pathology.

METHODS

A narrative review of the literature. A bibliographic search was performed on the PubMed, Science Direct, OVID, BIREME and Scielo databases, with the keywords: electrophysiological biomarker and substance use disorder, electrophysiological biomarker and mental disorders, biomarker and dual pathology, biomarker and substance use disorder, electroencephalography, and substance use disorder or comorbid mental disorder.

RESULTS

Given the greater amount of literature found in relation to electroencephalography as a biomarker of mental illness and substance use disorders, and the few articles found on dual pathology, the evidence is organised as a biomarker in psychiatry for the diagnosis and prediction of risk and as a biomarker for dual pathology.

CONCLUSIONS

Although the evidence is not conclusive, it suggests the existence of a subset of sites and mechanisms where the effects of psychoactive substances and the neurobiology of some mental disorders could overlap or interact.

Substance use during pregnancy and risk of postpartum depression: a systematic review and meta-analysis

Introduction

Postpartum depression (PPD) is a prevalent mental health condition affecting women globally within the first year following childbirth. Substance use during pregnancy has been associated with an increased risk of developing PPD, but the evidence remains inconclusive. This meta-analysis aims to comprehensively assess the effects of different substances on PPD risk, exploring potential modifiers and confounding factors.

Objectives

To examine the proportion of PPD among substance users during pregnancy, compared to non-users, and investigate the specific risk associated with different substances (tobacco, alcohol, and non-specified substance use/multiple substance use).

Methods

A systematic literature search was conducted from inception to November 2022 using the Web of Science database (Clarivate Analytics), incorporating Web of Science Core Collection, the BIOSIS Citation Index, the KCI-Korean Journal Database, MEDLINE®, the Russian Science Citation Index, the SciELO Citation Index, and the Cochrane Central Register of Reviews, and Ovid/PsycINFO databases. Inclusion criteria comprised original studies with pregnant women, using validated depression scales and substance use reporting.

Results

Among the 26 included studies, encompassing 514,441 women, the pooled prevalence of PPD among substance users during pregnancy was 29% (95% CI 25-33). Meta-analyzes revealed an overall odds ratio (OR) of 3.67 (95% CI 2.31-5.85, p < 0.01) indicating a significantly higher risk of PPD among substance users compared to non-users. Subgroup analyzes demonstrated a higher risk for women with non-specified or multiple substance use (OR 4.67, 95% CI 2.59-8.41; p < 0.01) and tobacco use (OR 4.01, 95% CI 2.23-7.20; p < 0.01). Alcohol use showed a trend toward higher risk that did not reach statistical significance (OR 1.88, 95% CI 1.00-3.55; p = 0.051).

Conclusion

This meta-analysis provides evidence of an increased risk of PPD among pregnant substance users, particularly those using multiple substances or tobacco. However, caution is needed in interpreting the association with alcohol use due to its non-significant result.

Systematic review registration

This study protocol was registered at PROSPERO (registration number: CCRD42022375500).

Potential health benefits of integrated screening strategies for alcohol, tobacco, other substance use, depression, anxiety, and chronic pain among people living with HIV in the USA: a mathematical modelling study

BACKGROUND

Alcohol use, tobacco use, and other substance use often co-occur with depression, anxiety, and chronic pain, forming a constellation of alcohol, substance, and mood-related (CASM) conditions that disproportionately affects people with HIV in the USA. We used a microsimulation model to evaluate how alternative screening strategies accounting for CASM interdependence could affect life expectancy in people with HIV in the USA.

METHODS

We augmented a microsimulation model previously validated to predict US adult life expectancy, including in people with HIV. Using data from the Veterans Aging Cohort Study, we incorporated CASM co-occurrence, inferred causal relationships between CASM conditions, and assessed the effects of CASM on HIV treatment and preventive care. We simulated an in-care HIV cohort exposed to alternative CASM screening and diagnostic assessment strategies, ranging from currently recommended screenings (alcohol, tobacco, and depression, with diagnostic assessments for conditions screening positive) to a series of integrated strategies (screening for alcohol, tobacco, or depression with additional diagnostic assessments if any screened positive) to a maximal saturation strategy (diagnostic assessments for all CASM conditions).

FINDINGS

The saturation strategy increased life expectancy by 0·95 years (95% CI 0·93-0·98) compared with no screening. Recommended screenings provided much less benefit: 0·06 years (0·03-0·09) gained from alcohol screening, 0·08 years (0·06-0·11) from tobacco screening, 0·10 years (0·08-0·11) from depression screening, and 0·25 years (0·22-0·27) from all three screenings together. One integrated strategy (screening alcohol, tobacco, and depression with diagnostic assessment for all CASM conditions if any screened positive) produced near-maximal benefit (0·82 years [0·80-0·84]) without adding substantial screening burden, albeit requiring additional diagnostic assessments.

INTERPRETATION

Primary care providers for people with HIV should consider comprehensive diagnostic assessment of CASM conditions if one or more conditions screen positive.

FUNDING

US National Institute on Alcohol Abuse and Alcoholism.

Maternal immune activation and adolescent alcohol exposure increase alcohol drinking and disrupt cortical-striatal-hippocampal oscillations in adult offspring

Maternal immune activation (MIA) is strongly associated with an increased risk of developing mental illness in adulthood, which often co-occurs with alcohol misuse. The current study aimed to begin to determine whether MIA, combined with adolescent alcohol exposure (AE), could be used as a model with which we could study the neurobiological mechanisms behind such co-occurring disorders. Pregnant Sprague-Dawley rats were treated with polyI:C or saline on gestational day 15. Half of the offspring were given continuous access to alcohol during adolescence, leading to four experimental groups: controls, MIA, AE, and Dual (MIA + AE). We then evaluated whether MIA and/or AE alter: (1) alcohol consumption; (2) locomotor behavior; and (3) cortical-striatal-hippocampal local field potentials (LFPs) in adult offspring. Dual rats, particularly females, drank significantly more alcohol in adulthood compared to all other groups. MIA led to reduced locomotor behavior in males only. Using machine learning to build predictive models from LFPs, we were able to differentiate Dual rats from control rats and AE rats in both sexes, and Dual rats from MIA rats in females. These data suggest that Dual "hits" (MIA + AE) increases substance use behavior and disrupts activity in reward-related circuits, and that this may be a valuable heuristic model we can use to study the neurobiological underpinnings of co-occurring disorders. Our future work aims to extend these findings to other addictive substances to enhance the translational relevance of this model, as well as determine whether amelioration of these circuit disruptions can reduce substance use behavior.

Traumatic Stress-Induced Vulnerability to Addiction: Critical Role of the Dynorphin/Kappa Opioid Receptor System

Substance use disorders (SUD) may emerge from an individual’s attempt to limit negative affective states and symptoms linked to stress. Indeed, SUD is highly comorbid with chronic stress, traumatic stress, or post-traumatic stress disorder (PTSD), and treatments approved for each pathology individually often failed to have a therapeutic efficiency in such comorbid patients. The kappa-opioid receptor (KOR) and its endogenous ligand dynorphin (DYN), seem to play a key role in the occurrence of this comorbidity. The DYN/KOR function is increased either in traumatic stress or during drug use, dependence acquisition and DYN is released during stress. The behavioural effects of stress related to the DYN/KOR system include anxiety, dissociative and depressive symptoms, as well as increased conditioned fear response. Furthermore, the DYN/KOR system is implicated in negative reinforcement after the euphoric effects of a drug of abuse ends. During chronic drug consumption DYN/KOR functions increase and facilitate tolerance and dependence. The drug-seeking behaviour induced by KOR activation can be retrieved either during the development of an addictive behaviour, or during relapse after withdrawal. DYN is known to be one of the most powerful negative modulators of dopamine signalling, notably in brain structures implicated in both reward and fear circuitries. KOR are also acting as inhibitory heteroreceptors on serotonin neurons. Moreover, the DYN/KOR system cross-regulate with corticotropin-releasing factor in the brain. The sexual dimorphism of the DYN/KOR system could be the cause of the gender differences observed in patients with SUD or/and traumatic stress-related pathologies. This review underlies experimental and clinical results emphasizing the DYN/KOR system as common mechanisms shared by SUD or/and traumatic stress-related pathologies, and suggests KOR antagonist as a new pharmacological strategy to treat this comorbidity.

Reactive and Regulative Temperament in Relation to Clinical Symptomatology and Personality Disorders in Patients with a Substance Use Disorder

Temperament and personality traits are important factors underlying the vulnerability for both the initiation and continuation of addictive behaviors. We investigated the influence of reactive and regulative temperament and their interaction in relation to clinical symptomatology and personality disorders (PDs) in a sample of 841 inpatients (68.1% males) with a substance use disorder (SUD). To assess reactive temperament we used the Behavioral Inhibition and Behavioral Activation Scales (BISBAS) and to assess regulative temperament we used the Effortful Control Scale. Clinical symptomatology and personality traits were measured by means of the Symptom Checklist-90 (SCL-90) and the Assessment of ADP-IV Personality Disorders (ADP-IV). Hierarchical regression analyses showed that both, clinical symptomatology and PDs were related to low levels of effortful control (EC). None of the two-way interactions (BIS × EC, BAS × EC) however were significantly related to psychopathology. Current findings highlight the role of effortful control (EC) in the expression of psychopathology in an adult sample of inpatients with SUD. Therapeutic interventions aiming at strengthening EC can possibly result in better treatment outcomes for both the addiction and the comorbid psychopathology.

BDNF and Cortisol in the Diagnosis of Cocaine-Induced Depression

BACKGROUND

Major depressive disorder (MDD) and cocaine use disorder (CUD) are related with disability and high mortality rates. The assessment and treatment of psychiatric comorbidity is challenging due to its high prevalence and its clinical severity, mostly due to suicide rates and the presence of medical comorbidities. The aim of this study is to investigate differences in brain derived neurotrophic factor (BDNF) and cortisol plasmatic levels in patients diagnosed with CUD-primary-MDD and CUD-induced-MDD and also to compare them to a sample of MDD patients (without cocaine use), a sample of CUD (without MDD), and a group of healthy controls (HC) after a stress challenge.

METHODS

A total of 46 subjects were included: MDD (n = 6), CUD (n = 15), CUD-primary-MDD (n = 16), CUD-induced-MDD (n = 9), and 21 HC. Psychiatric comorbidity was assessed with the Spanish version of the Psychiatric Research Interview for Substance and Mental Disorders IV (PRISM-IV), and depression severity was measured with the Hamilton Depression Rating Scale (HDRS). Patients were administered the Trier Social Stress Test (TSST) before and after the biological measures, including BDNF, and cortisol levels were obtained.

RESULTS

After the TSST, Cohen's d values between CUD-primary-MDD and CUD-induced-MDD increased in each assessment from 0.19 post-TSST to 2.04 post-90-TSST. Pairwise differences among CUD-induced-MDD and both MDD and HC groups had also a large effect size value in post-30-TSST and post-90-TSST. In the case of the BDNF concentrations, CUD-primary-MDD and CUD-induced-MDD in post-90-TSST (12,627.27 ± 5488.09 vs.17,144.84 ± 6581.06, respectively) had a large effect size (0.77).

CONCLUSION

Results suggest a different pathogenesis for CUD-induced-MDD with higher levels of cortisol and BDNF compared with CUD-primary-MDD. Such variations should imply different approaches in treatment.

Effects of low-dose alcohol exposure in adolescence on subsequent alcohol drinking in adulthood in a rat model of depression

OBJECTIVE

Adolescence drinking and subsequent development of alcohol use disorder (AUD) is a worldwide health concern. In particular, mood dysregulation or early alcohol exposure can be the cause of heavy drinking in some individuals or a consequence of heavy drinking in others.

METHODS

This study investigated the effects of voluntary alcohol intake during adolescence, i.e. continuous 10% alcohol access between postnatal days (PND) 29 to 43 and olfactory bulbectomy (OBX) model of depression (performed on PND 59) on alcohol drinking in Wistar rats during adulthood (PND 80-120, intermittent 20% alcohol access). In addition, the effect of NBQX, an AMPA/kainate receptor antagonist (5 mg/kg, IP) on spontaneous alcohol consumption was examined.

RESULTS

Rats exposed to 10% alcohol during adolescence exhibited a lower 20% alcohol intake in the intermittent paradigm during adulthood, while the OBX-induced phenotype did not exert a significant effect on the drinking behaviour. NBQX exerted a transient reduction on alcohol intake in the OBX rats.

CONCLUSIONS

Our results indicate that exposure to alcohol during adolescence can affect alcohol drinking in adulthood and that further exploration of AMPA and/or kainate receptor antagonists in co-morbid alcoholism-depression is warranted.

Biomarkers for alcohol abuse/withdrawal and their association with clinical scales and temptation to drink. A prospective pilot study during 4-week residential rehabilitation

A bulk of evidence in the field of translational medicine applied to clinical toxicology and rehabilitation has highlighted the possibility of using biomarkers as a support in the diagnosis of alcohol-related diseases and in monitoring of alcohol withdrawal. In a cohort of 55 subjects admitted to a 4-week residential rehabilitation period for alcohol detoxification, we applied a complementary approach correlating novel and conventional peripheral blood and urine parameters in combination with clinical and functional evaluation, contextually considered with the patient's history. Biomarkers of oxidative, inflammatory, hepatic, and neurochemical effects paralleled by alcohol craving and clinical scale measurements were determined at two specific time points, i.e., admission and discharge. Concerning the post-discharge assessment (i.e., relapse evaluation one month after discharge), a follow-up oral interview during a clinical examination was applied to evaluate alcohol abstinence.Selected biomarkers, i.e., MCP1, F2-IsoPs, and SOD1, were altered in chronic alcoholics at admission, and then showed a clearly changing trend during hospitalization. Our findings demonstrated that these specific non-traditional biomarkers, measured together with more conventional ones (e.g., CDT, EtG, IL8, ALT, AST, GGT), could represent novel key parameters for monitoring alcohol use disorders and withdrawal, being also suggestive of the complexity of the psychoneuroimmune response to alcohol. A general improvement in psychological functioning (i.e., decreases in anxiety, depression, and psychological distress) was also revealed during the 4-week rehabilitation treatment, paralleled by an increase of well-being and positive changes in terms of scores. Moreover, a positive association between SOD1 and drink craving at admission was evidenced. Notably, both SOD1 and well-being displayed a significant relation with lower risk of alcohol relapse one month after discharge, indicating that SOD1 is a good predictor of reduced relapse probability. This 4-week residential rehabilitation protocol represents a sound strategy enabling identification of alcohol use disorders and monitoring of alcohol addiction state and withdrawal. However, it has to be emphasized that results derived from this pilot study need to be extensively validated in large and independent cohorts of subjects.

The phenomics and genetics of addictive and affective comorbidity in opioid use disorder

Opioid use disorder (OUD) creates significant public health and economic burdens worldwide. Therefore, understanding the risk factors that lead to the development of OUD is fundamental to reducing both its prevalence and its impact. Significant sources of OUD risk include co-occurring lifetime and current diagnoses of both psychiatric disorders, primarily mood disorders, and other substance use disorders, and unique and shared genetic factors. Although there appears to be pleiotropy between OUD and both mood and substance use disorders, this aspect of OUD risk is poorly understood. In this review, we describe the prevalence and clinical significance of addictive and affective comorbidities as risk factors for OUD development as a basis for rational opioid prescribing and OUD treatment and to improve efforts to prevent the disorder. We also review the genetic variants that have been associated with OUD and other addictive and affective disorders to highlight targets for future study and risk assessment protocols.

Molecular genetics of substance use disorders: An umbrella review

BACKGROUND

Substance use disorders (SUD) are a category of psychiatric disorders with a large epidemiological and societal impact around the world. In the last decades, a large number of genetic studies have been published for SUDs.

METHODS

With the objective of having an overview and summarizing the evidence published up to date, we carried out an umbrella review of all the meta-analyses of genetic studies for the following substances: alcohol, tobacco, cannabis, cocaine, opioids, heroin and methamphetamines. Meta-analyses for candidate gene studies and genome-wide association studies (GWAS) were included.

RESULTS

Alcohol and tobacco were the substances with the largest number of meta-analyses, and cannabis, opioids and cocaine the least studied. The following genes were associated with two or more SUDs: OPRM1, DRD2, DRD4, BDNF and SL6A4. The only genes that had an OR higher than two were the SLC6A4 for all addictions, the ADH1B for alcohol dependence, and BDNF for methamphetamine dependence. GWAS confirmed the possible role of CHRNA5 gene in nicotine dependence and identified novel candidate genes in other SUDs, such as FOXP2, PEX and, AUTS2, which need further functional analyses.

CONCLUSIONS

This umbrella review summarizes the evidence of 16 years of research on the genetics of SUDs and provides a broad and detailed overview of results from more than 150 meta-analyses for SUD. The results of this umbrella review will guide the need for future genetic studies geared toward understanding, preventing and treating SUDs.

The Tryptophan System in Cocaine-Induced Depression

Major depression disorder (MDD) is the most prevalent psychiatric comorbid condition in cocaine use disorder (CUD). The comorbid MDD might be primary-MDD (CUD-primary-MDD) or cocaine-induced MDD (CUD-induced-MDD), and their accurate diagnoses and treatment is a challenge for improving prognoses. This study aimed to assess the tryptophan/serotonin (Trp/5-HT) system with the acute tryptophan depletion test (ATD), and the kynurenine pathway in subjects with CUD-primary-MDD, CUD-induced-MDD, MDD and healthy controls. The ATD was performed with a randomized, double-blind, crossover, and placebo-controlled design. Markers of enzymatic activity of indoleamine 2,3-dioxygenase/tryptophan 2,3-dioxygenase, kynurenine aminotransferase (KAT) and kynureninase were also established. Following ATD, we observed a decrease in Trp levels in all groups. Comparison between CUD-induced-MDD and MDD revealed significant differences in 5-HT plasma concentrations (512 + 332 ng/mL vs. 107 + 127 ng/mL, p = 0.039) and the Kyn/5-HT ratio (11 + 15 vs. 112 + 136; p = 0.012), whereas there were no differences between CUD-primary-MDD and MDD. Effect size coefficients show a gradient for all targeted markers (d range 0.72-1.67). Results suggest different pathogenesis for CUD-induced-MDD, with lower participation of the tryptophan system, probably more related to other neurotransmitter pathways and accordingly suggesting the need for a different pharmacological treatment approach.

Depression and substance use disorders: Clinical comorbidity and shared neurobiology

Mood disorders, including major depressive disorder (MDD), are the most prevalent psychiatric illnesses, and pose an incredible burden to society, both in terms of disability and in terms of costs associated with medical care and lost work time. MDD has extremely high rates of comorbidity with substance use disorders (SUD) as many of the same neurobiological circuits and molecular mechanisms regulate the reward pathways disrupted in both conditions. MDD may induce SUDs, SUD may contribute to MDD development, or underlying vulnerabilities and common life experience may confer risk to developing both conditions. In this chapter we explore theories of MDD and SUD comorbidity, the neurobiological underpinnings of depression, overlapping cellular and molecular pathways for both conditions, and current treatment approaches for these comorbid conditions.

The increased density of the habenular neurons, high impulsivity, aggression and resistant fear memory in Disc1-Q31L genetic mouse model of depression

Mood disorders affect nearly 300 million humans worldwide, and it is a leading cause of death from suicide. In the last decade, the habenula has gained increased attention due to its major role to modulate emotional behavior and related psychopathologies, including depression and bipolar disorder, through the modulation of monoamines' neurotransmission. However, it is still unclear which genetic factors may directly affect the function of the habenula and hence, could contribute to the psychopathological mechanisms of mood disorders. Disrupted-In-Schizophrenia-1 (DISC1) gene is among robust gene-candidates predisposing to major depression, bipolar disorder and schizophrenia in humans. DISC1-Q31L, a well-established genetic mouse model of depression, offers a unique opportunity for translational studies. The current study aimed to probe morphological features of the habenula in the DISC1-Q31L mouse line and detect novel behavioral endophenotypes, including the increased emotionality in mutant females, high aggression in mutant males and deficient extinction of fear memory in DISC1 mutant mice of both sexes. The histological analysis found the increased neural density in the lateral and medial habenula in DISC1-Q31L mice regardless of sex, hence, excluding direct association between the habenular neurons and emotionality in mutant females. Altogether, our findings demonstrated, for the first time, the direct impact of the DISC1 gene on the habenular neurons and affective behavior in the DISC1-Q31L genetic mouse line. These new findings suggest that the combination of the DISC1 genetic analysis together with habenular neuroimaging may improve diagnostics of mood disorder in clinical studies.

Emotional health outcomes are influenced by sexual minority identity and HIV serostatus

For people living with HIV (PLWH) and sexual minorities (SM), the intersection of identities can compound experiences like stigma and discrimination resulting in poor emotional health. We investigated the separate and interactive associations of HIV serostatus and sexual identity with emotional health. Our dataset included 371 participants. Emotional health was assessed by the NIH Toolbox emotion battery which yields negative affect, social satisfaction, and psychological well-being. Regressions were conducted for each composite, with HIV serostatus, sexual identity, and their interaction as independent variables along with covariates. The HIV serostatus x SM identity interaction was statistically significant in the regression of Negative Affect (p = .01): heterosexuals living with HIV had worse Negative Affect compared to heterosexual HIV-persons (p = .01). The interaction terms were for social satisfaction and psychological well-being were not significant. However, among PLWH, sexual minorities reported better Social Satisfaction (p = .03) and marginally better psychological well-being (p = .07) compared to heterosexuals.

Delineating the Psychic Structure of Substance Use and Addictions, from Neurobiology to Clinical Implications: Ten Years Later

The diagnosis of substance use disorder is currently based on the presence of specifically identified behavioral symptoms. In addition, other psychiatric signs and symptoms accompany addictive behavior, contributing to the full picture of patients’ psychopathologic profile. Historically, such symptoms were confined within the framework of “comorbidity”, as comorbid psychiatric disorders or personality traits. However, an alternative unitary view of the psychopathology of addiction, inclusive of related psychiatric symptoms, has been claimed, with the support of epidemiological, neurobiological, and neuropsychological evidence. In the present article, we highlight the research advancements that strengthen this unified perspective. We then give an account of our group’s definition of a specific SCL-90-based construct of the psychopathology of addiction. Lastly, we discuss the benefits that can be expected to be acquired in the evaluation and treatment of patients with a longitudinal approach including psychological/psychiatric predisposing features, addictive behavior, and psychiatric manifestations.

Prevalence of comorbid substance use in major depressive disorder in community and clinical settings, 1990-2019: Systematic review and meta-analysis

BACKGROUND

Comorbidity between Substance Use Disorders (SUDs) and major depression is highly prevalent. This systematic review and meta-analysis aimed to estimate the prevalence of SUDs in subjects diagnosed with a major depressive disorder (MDD) in community, inpatient and outpatient settings.

METHODS

A comprehensive literature search of Medline, EMBASE, PsycINFO and CINAHL databases was conducted from 1990 to 2019. Prevalence of co-morbid SUDs and MDD were extracted and odds ratios (ORs) were calculated using random effects meta-analysis.

RESULTS

There were 48 articles identified by electronic searches with a total sample size of 348,550 subjects that yielded 14 unique epidemiological studies, 2 national case registry studies, 7 large cohort studies and 20 clinical studies using in- or out-patients. The prevalence of any SUD in individuals with MDD was 0.250. Maximum prevalence was found with alcohol use disorder (0.208), followed by illicit drug use disorder (0.118) and cannabis use disorder (0.117). Meta-analysis showed the pooled variance of any AUD in men with MDD was 36%, which was significantly higher than that for females with MDD (19%, OR 2.628 95% CI 2.502, 2.760).

CONCLUSIONS

Few studies were published over the last decade so current prevalence rates of SUD in MDD are needed. Meta-analysis revealed that SUDs in MDD are highly prevalent and rates have not changed over time. The persistently high prevalence suggests there is an urgent need for more informative studies to help develop better prevention and treatment options for reducing prevalence of SUDs in persons with major depression and co-morbid disorders.

Modulation of the NOP receptor signaling affects resilience to acute stress

BACKGROUND

The peptide nociceptin/orphanin FQ (N/OFQ) and its receptor (NOP) are implicated in the modulation of emotional states. Previous human and rodent findings support NOP antagonists as antidepressants. However, the role played by the N/OFQ-NOP receptor system in resilience to stress is unclear.

AIMS

The present study investigated the effects of activation or blockade of NOP receptor signaling before exposure to acute stress.

METHODS

The behavioral effects of the administration before stress of the NOP agonists Ro 65-6570 (0.01-1 mg/kg) and MCOPPB (0.1-10 mg/kg), and the NOP antagonist SB-612111 (1-10 mg/kg) were assessed in mice exposed to inescapable electric footshock and forced swim as stressors. The behavioral phenotype of mice lacking the NOP receptor (NOP(-/-)) exposed to inescapable electric footshock was also investigated.

RESULTS

The activation of NOP receptor signaling with the agonists increased the percentage of mice developing helpless behavior and facilitated immobile posture. In contrast, the blockade of NOP receptor reduced the acquisition of depressive-like phenotypes, and similar resistance to develop helpless behaviors was observed in NOP(-/-) mice. Under the same stressful conditions, the antidepressant nortriptyline (20 mg/kg) did not change the acquisition of helpless behavior and immobile posture.

CONCLUSIONS

These findings support the view that NOP activation during acute stress facilitates the development of depressive-related behaviors, whereas NOP blockade has a protective outcome. This study showed for first time that NOP antagonists are worthy of investigation as preemptive treatments in patients with severe risk factors for depression.

Clinical Correlates of Alcohol Use Disorder in Depressed Patients with Unipolar and Bipolar Disorder

OBJECTIVE

Alcohol use disorder (AUD) is one of the most frequent comorbid conditions in mood disorders. We aimed to examine the relationships between clinical phenotypes of acutely depressed subjects and co-occurring AUD.

METHODS

Clinical assessment including diagnosis of mood disorder and co-occurring AUD, the severity of depressive or manic symptoms, and affective temperaments were conducted in 137 subjects suffering from a major depressive episode. According to the presence of AUD, clinical variables were compared between the two groups. Using binary logistic regression models, the effects of mood symptoms and affective temperaments on the risk of AUD were determined.

RESULTS

Severity of manic symptoms, suicidal ideation, and childhood trauma were higher in the AUD group than in the non-AUD group. Scores for irritable and hyperthymic temperament were higher and the score for anxious temperament was lower in the AUD group. In regression models adjusting confounders, anxious temperament was an independent protector against AUD. On the other hand, the diagnosis of bipolar disorder and the irritable manic symptom dimension increased the risk of AUD.

CONCLUSION

Anxious temperament decreased the AUD risk, whereas irritable manic symptoms increased the risk during depression. AUD in mood disorders may be an expression of manic psychopathology.

Structural brain characteristics of anabolic-androgenic steroid dependence in men

AIM

To identify differences in brain morphology between dependent and non-dependent male anabolic-androgenic steroid (AAS) users.

DESIGN

This study used cross-sectional data from a longitudinal study on male weightlifters.

PARTICIPANTS

Oslo University Hospital, Norway.

SETTING

Eighty-one AAS users were divided into two groups; AAS-dependent (n = 43) and AAS-non-dependent (n = 38).

MEASUREMENTS

Neuroanatomical volumes and cerebral cortical thickness were estimated based on magnetic resonance imaging (MRI) using FreeSurfer. Background and health information were obtained using a semi-structured interview. AAS-dependence was evaluated in a standardized clinical interview using a version of the Structured Clinical Interview for DSM-IV, adapted to apply to AAS-dependence.

FINDINGS

Compared with non-dependent users, dependent users had significantly thinner cortex in three clusters of the right hemisphere and in five clusters of the left hemisphere, including frontal, temporal, parietal and occipital regions. Profound differences were seen in frontal regions (left pars orbitalis, cluster-wise P < 0.001, right superior frontal, cluster-wise P < 0.001), as has been observed in other dependencies. Group differences were also seen when excluding participants with previous or current non-AAS drug abuse (left pre-central, cluster-wise P < 0.001, left pars orbitalis, cluster-wise P = 0.010).

CONCLUSION

Male dependent anabolic-androgenic steroid users appear to have thinner cortex in widespread regions, specifically in pre-frontal areas involved in inhibitory control and emotional regulation, compared with non-dependent anabolic-androgenic steroid users.

Prior Exposure to Salient Win-Paired Cues in a Rat Gambling Task Increases Sensitivity to Cocaine Self-Administration and Suppresses Dopamine Efflux in Nucleus Accumbens: Support for the Reward Deficiency Hypothesis of Addiction

Rats trained to perform a version of the rat gambling task (rGT) in which salient audiovisual cues accompany reward delivery, similar to commercial gambling products, show greater preference for risky options. Given previous demonstrations that probabilistic reinforcement schedules can enhance psychostimulant-induced increases in accumbal DA and locomotor activity, we theorized that performing this cued task could perpetuate a proaddiction phenotype. Significantly more rats developed a preference for the risky options in the cued versus uncued rGT at baseline, and this bias was further exacerbated by cocaine self-administration, whereas the choice pattern of optimal decision-makers was unaffected. The addition of reward-paired cues therefore increased the proportion of rats exhibiting a maladaptive cognitive response to cocaine self-administration. Risky choice was not associated with responding for conditioned reinforcement or a marker of goal/sign-tracking, suggesting that reward-concurrent cues precipitate maladaptive choice via a unique mechanism unrelated to simple approach toward, or responding for, conditioned stimuli. Although "protected" from any resulting decision-making impairment, optimal decision-makers trained on the cued rGT nevertheless self-administered more cocaine than those trained on the uncued task. Collectively, these data suggest that repeated engagement with heavily cued probabilistic reward schedules can drive addiction vulnerability through multiple behavioral mechanisms. Rats trained on the cued rGT also exhibited blunted locomotor sensitization and lower basal accumbal DA levels, yet greater cocaine-induced increases in accumbal DA efflux. Gambling in the presence of salient cues may therefore result in an adaptive downregulation of the mesolimbic DA system, rendering individuals more sensitive to the deleterious effects of taking cocaine.SIGNIFICANCE STATEMENT Impaired cost/benefit decision making, exemplified by preference for the risky, disadvantageous options on the Iowa Gambling Task, is associated with greater risk of relapse and treatment failure in substance use disorder. Understanding factors that enhance preference for risk may help elucidate the neurobiological mechanisms underlying maladaptive decision making in addiction, thereby improving treatment outcomes. Problem gambling is also highly comorbid with substance use disorder, and many commercial gambling products incorporate salient win-paired cues. Here we show that adding reward-concurrent cues to a rat analog of the IGT precipitates a hypodopaminergic state, characterized by blunted accumbal DA efflux and attenuated locomotor sensitization, which may contribute to the enhanced responsivity to uncertain rewards or the reinforcing effects of cocaine we observed.

De vuelta a la clínica: sin justificación no existe pregunta de investigación que valga

A clinical research question requires the concurrence of clinical experience and knowledge on methodology and statistics in that who formulates it. Initially, a research question should have a structure that clearly establishes what is that which is being sought (consequence or outcome), in whom (baseline status), and by action of what (maneuver). Subsequently, its reasoning must explore four aspects: feasibility and reasonableness of the questioning, lack of a prior answer, relevance of the answer to be obtained, and applicability. Once these aspects are satisfactorily covered, the question can be regarded as being "clinically relevant", which is different from being statistically significant, which refers to the probability of the result being driven by chance, which does not reflect the relevance of the question or the outcome. One should never forget that every maneuver entails adverse events that, when serious, discredit good results. It is imperative to have the possible answer estimated from within the structure of the question. The function of clinical research is to corroborate or reject a hypothesis, rather than to empirically test to find out what the outcome is.