Generalized anxiety disorder and major depressive disorder comorbidity: an example of genetic pleiotropy?

Greater within- and between-day instability is associated with worse anxiety and depression symptoms

BACKGROUND

Depression and anxiety affect hundreds of millions of people worldwide, and their prevalence increased during the COVID-19 pandemic as social schedules were disrupted. This study explores the associations between anxiety and depression and within- and between-day instability of affective, somatic, and cognitive symptoms during the early pandemic stages.

METHODS

Participants (n = 153, ages 18-77, 72 % female) reported daily levels of affective (anxiety/sadness), somatic (appetite/sleepiness), and cognitive (concentration/energy) symptoms for 14-44 days at five timepoints: 0, 3, 6, 9, and 12 h after awakening. At the end of the study, participants completed validated scales for anxiety (GAD-7) and depression (PHQ-9). Symptom instability was assessed using the Absolute Real Variability (ARV) index. Regression models examined within-day instability (WD-I) and between-day instability (BD-I) with GAD-7 and PHQ-9 scores as outcomes.

RESULTS

Greater instability (both WD-I and BD-I) of affective symptoms correlated with elevated GAD-7 and PHQ-9 scores. For somatic and cognitive symptoms, greater BD-I was associated with higher scores.

LIMITATIONS

The study used retrospective daily data, which could benefit from real-time assessments for improved accuracy.

CONCLUSIONS

This study provides empirical evidence of a connection between greater anxiety and depression severity and increased instability in daily mood and physiological symptoms. The findings underscore the importance of consistent symptom monitoring to understand overall mental health trajectories. Additionally, it highlights the role of daily routines in stabilizing the circadian system, potentially regulating physiological and psychological processes and reducing symptom instability.

Global Impacts of Western Diet and Its Effects on Metabolism and Health: A Narrative Review

The Western diet is a modern dietary pattern characterized by high intakes of pre-packaged foods, refined grains, red meat, processed meat, high-sugar drinks, candy, sweets, fried foods, conventionally raised animal products, high-fat dairy products, and high-fructose products. The present review aims to describe the effect of the Western pattern diet on the metabolism, inflammation, and antioxidant status; the impact on gut microbiota and mitochondrial fitness; the effect of on cardiovascular health, mental health, and cancer; and the sanitary cost of the Western diet. To achieve this goal, a consensus critical review was conducted using primary sources, such as scientific articles, and secondary sources, including bibliographic indexes, databases, and web pages. Scopus, Embase, Science Direct, Sports Discuss, ResearchGate, and the Web of Science were used to complete the assignment. MeSH-compliant keywords such "Western diet", "inflammation", "metabolic health", "metabolic fitness", "heart disease", "cancer", "oxidative stress", "mental health", and "metabolism" were used. The following exclusion criteria were applied: (i) studies with inappropriate or irrelevant topics, not germane to the review's primary focus; (ii) Ph.D. dissertations, proceedings of conferences, and unpublished studies. This information will allow for a better comprehension of this nutritional behavior and its effect on an individual's metabolism and health, as well as the impact on national sanitary systems. Finally, practical applications derived from this information are made.

Multimorbidity and Correlates of Comorbid Depression and Generalized Anxiety Disorder in a Nationally Representative US Sample

ABSTRACT

Generalized anxiety disorder (GAD) and major depressive disorder (MDD) frequently occur together, but sociodemographic, behavioral, and diagnostic correlates of this comorbidity have not been comprehensively studied. Data from the nationally representative US sample surveyed in the National Epidemiologic Survey on Alcohol and Related Conditions-III ( N = 36,309) were used to define three groups, individuals with a) both past-year GAD and MDD ( n = 909, 16.9%), b) GAD only ( n = 999, 18.6%), and c) MDD only ( n = 3471, 64.5%). The comorbid group was compared with each single-diagnosis group on sociodemographic, behavioral, and diagnostic characteristics based on effect sizes (risk ratios and Cohen's d ) rather than p values because of the large sample sizes. Multivariable-adjusted logistic regression analyses were used to identify factors independently associated with the comorbid group. Bivariate analysis showed that the comorbid group had more parental and childhood adversities, additional psychiatric disorders, and poorer mental health quality of life than both single-disorder groups. Multivariable-adjusted logistic regression of the comorbid group showed that on two of five factors, additional psychiatric diagnoses were significantly more frequent than in the GAD-only group, and that on three of six factors, additional psychiatric diagnoses were significantly more frequent than in the MDD-only group. There is a significantly higher burden of social adjustment problems, comorbid psychiatric disorders, and poorer mental health-related quality of life among individuals with comorbid GAD-MDD than those with single disorders. The adversities associated with this non-SUD psychiatric comorbidity are comparable to those associated with the more extensively studied comorbidity of psychiatric and substance use disorders and deserve further research and treatment.

Chronic mild stress induces differential depression-like symptoms and c-Fos and 5HT1A protein levels in high-anxiety female Long Evans rats

Depression and anxiety disorders overlap in clinical populations, suggesting common mechanisms that may be further investigated in reliable animal models. We used filial 8 female Long-Evans rats bred for high (HAn; n = 19) and low anxiety (LAn)-like behavior (n = 21) to assess forced swim test mobility strategies and chronic mild stress (CMS)-induced depression-like symptoms. We measured (1) weight, (2) fur piloerection, (3) sweet food consumption, (4) grooming behavior, and (5) circulating estradiol (E2). One month after CMS terminated and following a terminal forced swim test, brains were processed for immunohistochemistry targeting c-Fos and serotonin 1 A receptor (5-HT1AR) protein in the paraventricular nucleus (PVN) of the hypothalamus. HAn female rats showed increased anxiety-like behavior (i.e., lower open to closed arm ratios, increased closed arm entries), more swimming (i.e., mobility), and less floating (i.e., immobility) behavior in the forced swim test. Overall, HAn females weighed less than their LAn counterparts. After chronic mild stress, HAn lines displayed even greater mobility and consumed fewer Froot Loops™. Fur and grooming analyses indicated no significant differences in mean counts across experimental groups. One month after CMS, cycling E2 concentrations (pg/ml) did not differ between HAn and LAn animals. Elevated c-Fos and 5-HT1AR expression were observed in the PVN, where HAn CMS rats expressed the most c-Fos and 5-HT1AR immunoreactivity. In summary, outbred HAn rats show robust anxiety-like behavior, exhibit more mobility in the forced swim test, and are more sensitive to chronic mild stress-induced grooming and decline in palatable food ingestion.

Pharmacogenetics of anxiety disorders

Anxiety disorders are common and disabling conditions the treatment of which remains a challenge. While different groups of medication are available for their treatment, a substantial proportion of patients remain refractory to pharmacotherapy. The reason for this variation in the individual response to treatment has yet to be understood; however genetic factors have been shown to play an important role. Up to now there have been limited publications about pharmacogenetics of anxiety disorders, compared to studies in depression. Published studies are focused on pharmacogenetics of antidepressants rather than being disease specific. This review summarizes pharmacogenetic findings related to the anxiolytic treatment response and their possible functional mechanisms. This inevitably focuses on genes involved in the pharmacodynamics of the medications used, along with some genes implicated in the disease process, as well as briefly mentioning genetic factors associated with psychotherapeutic response.

Threat-sensitivity in affective disorders: A case-control study

BACKGROUND

Anxiety disorders are highly comorbid with major depression but differ in their symptom profiles and pharmacological responses. Threat-sensitivity may explain such differences, yet research on its relationship to specific disorders is lacking.

METHODS

One-hundred patients (71 women) and 35 healthy controls (23 women) were recruited. Thirty-five had Panic Disorder (PD), 32 had Generalized Anxiety Disorder (GAD) and 33 Major Depressive Disorder (MDD). Threat-sensitivity was measured via behaviour (Joystick Operated Runway Task; JORT) and self-report (Fear Survey Schedule; FSS).

RESULTS

Behavioural sensitivity to simple threat was higher in females compared to males (p = .03). Self-reported sensitivity to simple threat (FSS Tissue Damage Fear) was higher in PD patients compared to other groups (p ≤ .007) and in GAD patients compared to controls (p = .02). Behavioural sensitivity to complex threat was higher in females than males (p = .03) and a group by sex interaction (p = .01) indicated that this difference was largest in PD patients. Self-reported sensitivity to complex threat (FSS Social Fear) was higher in all patients compared to controls (p ≤ .001). Females scored higher than males on FSS Tissue Damage Fear and FSS Social Fear).

CONCLUSIONS

Our findings oppose the simple/complex threat dichotomy, instead suggesting elevated sensitivity to physical threat differentiates anxiety disorders from MDD, whereas elevated sensitivity to social threat is associated with both anxiety disorders and MDD.

Alpha2-adrenergic dysregulation in congenic DxH recombinant inbred mice selectively bred for a high fear-sensitized (H-FSS) startle response

Patients with anxiety disorders and posttraumatic stress disorder (PTSD) exhibit exaggerated fear responses and noradrenergic dysregulation. Fear-related responses to α₂-adrenergic challenge were therefore studied in DxH C3H/HeJ-like recombinant inbred (C3HLRI) mice, which are a DBA/2J-congenic strain selectively bred for a high fear-sensitized startle (H-FSS). C3HLRI mice showed an enhanced acoustic startle response and immobility in the forced swim test compared to DBA/2J controls. The α₂-adrenoceptor antagonist yohimbine (Yoh; 5.0 mg/kg) induced an anxiogenic and the α₂-adrenoceptor agonist clonidine (Clon; 0.1 mg/kg) an anxiolytic effect in the open field (OF) in C3HLRI but not DBA/2J mice. In auditory fear-conditioning, Yoh (5.0 mg/kg)-treated C3HLRI mice showed higher freezing during fear recall and extinction learning than DBA/2J mice, and a higher ceiling for the Yoh-induced deficit in fear extinction. No strain differences were observed in exploration-related anxiety/spatial learning or the Clon-induced (0.1 mg/kg) corticosterone surge. A global analysis of the behavioral profile of the two mouse strains based on observed and expected numbers of significant behavioral outcomes indicated that C3HLRI mice showed significantly more often fear- and stress-related PTSD-like behaviors than DBA/2J controls. The analysis of the robustness of significant outcomes based on false discovery rate (FDR) thresholds confirmed significant differences for the strain-Yoh-interactions in the OF center and periphery, the Yoh-induced general extinction deficit, strain differences in conditioned fear levels, and at the dose of 5.0 mg/kg for the Yoh-induced ceiling in freezing levels among others. The current findings are consistent with previous observations showing alterations in the central noradrenergic system of C3HLRI mice (Browne et al., 2014, Stress 17:471-83). Based on their behavioral profile and response to α₂-adrenergic stimulation, C3HLRI mice are a valuable genetic model for studying adrenergic mechanisms of anxiety disorders and potentially also of PTSD.

Experiential Avoidance Predicts Persistence of Major Depressive Disorder and Generalized Anxiety Disorder in Late Adolescence

OBJECTIVE

Experiential avoidance (EA) is a transdiagnostic construct that may underlie the high comorbidity between major depressive disorder (MDD) and generalized anxiety disorder (GAD). This analysis used data from a longitudinal study (conducted September 2010-April 2016) to examine whether adolescent EA varies by MDD and GAD symptomatology trajectory and predicts said trajectories. Longitudinal associations between EA, anxiety, and depression symptoms were also examined.

METHODS

Adolescents aged 15 to 20 years (N = 183) were followed for 2 years using a comprehensive assessment battery. Symptom trajectory modeling, using weekly symptom ratings, identified 4 MDD and 4 GAD trajectories that were collapsed to form combined MDD/GAD trajectory groups: Persistent (n = 81), High-Decreasing (n = 44), Normal-Increasing (n = 37), and Minimal (n = 21). Group-based trajectory modeling, analyses of covariance, structural equation modeling, and linear regression analyses were performed. DSM-IV-TR criteria were used for MDD and GAD diagnoses.

RESULTS

The Persistent adolescents had higher EA than other groups (P values ≤ .001), with greater EA stability versus High-Decreasing adolescents (P = .008). EA predicted anxiety and depressive symptoms alike (P values ≤ .005), which in turn did not predict EA (P values ≥ .188). EA, at both time points, predicted combined MDD/GAD trajectories after adjustment for depressive and anxiety symptoms and other confounders (P values < .001).

CONCLUSIONS

EA appears to be an important predictor of MDD and GAD symptomatology in older adolescents, potentially serving as a treatment target. Findings suggest a possible trait-like nature for EA, perhaps increasing risk for the emergence and persistence of MDD and/or GAD.

TRIAL REGISTRATION

ClinicalTrials.gov identifier: NCT02147184​.

Neurotransmitter receptor genotypes associated with mental and behavioral disorders

AIM

Investigation of association studies within the field of mental and behavioral disorders is of value given their complex molecular etiology including epistatic interactions of multiple genes with small effects.

MATERIALS & METHODS

Utilizing biomedical text mining, associations are uncovered for all mental and behavioral conditions listed in Diagnostic and Statistical Manual of Mental Disorders Text Revision. Specifically, a computational pipeline is designed to retrieve neurotransmitter receptor variations from biomedical literature with a text mining approach, where unique polymorphisms are also mined.

RESULTS

Analyses of 1337 unique neurotransmitter receptors and 465 distinct conditions yield 1568 unique gene-disease associations.

CONCLUSION

This study takes an unconventional approach to association studies and generates a novel dataset of associations for disorders such as major depression and schizophrenia, which provides a global perspective for their genetic etiology.

The history of generalized anxiety disorder as a diagnostic category

From the 19th century into the 20th century, the terms used to diagnose generalized anxiety included “pantophobia” and “anxiety neurosis.” Such terms designated paroxysmal manifestations (panic attacks) as well as interparoxysmal phenomenology (the apprehensive mental state). Also, generalized anxiety was considered one of numerous symptoms of neurasthenia, a vaguely defined illness. Generalized anxiety disorder (GAD) appeared as a diagnostic category in the third edition of the Diagnostic and Statistical Manual of Mental Disorders (DSM-III) in 1980, when anxiety neurosis was split into GAD and panic disorder. The distinct responses these two disorders had to imipramine therapy was one reason to distinguish between the two. Since the revised DSM-III (DSM-III-R), worry about a number of life circumstances has been gradually emphasized as the distinctive symptom of GAD. Thus, a cognitive aspect of anxiety has become the core criterion of GAD. The validity of GAD as an independent category has been questioned from DSM-III up to preparation of DSM-5. Areas of concern have included the difficulty to establish clear boundaries between GAD and (i) personality dimensions, (ii) other anxiety-spectrum disorders, and (iii) nonbipolar depression. The National Institute of Mental Health has recently proposed the Research Domain Criteria (RDoC), a framework destined to facilitate biological research into the etiology of mental symptoms. Within the RDoC framework, generalized anxiety might be studied as a dimension denominated “anxious apprehension” that would typically fit into the research domain called “negative valence systems” and the more specific construct termed “potential threat.”

Severity of complicated versus uncomplicated subthreshold depression: New evidence on the "Monotonicity Thesis" from the national comorbidity survey

BACKGROUND

"Complicated" subthreshold depression (CsD) includes at least one of six pathosuggestive "complicated" symptoms: >6 months duration, marked role impairment, sense of worthlessness, suicidal ideation, psychotic ideation, and psychomotor retardation. "Uncomplicated" subthreshold depression (UsD) has no complicated features. Whereas studies show that complicated (CMDD) versus uncomplicated (UMDD) major depression differ substantially in severity and prognosis, UsD and CsD severity has not been previously compared. This study evaluates UsD and CsD pathology validator levels and examines whether the complicated/uncomplicated distinction offers incremental concurrent validity over the standard number-of-symptoms dimension as a depression severity measure.

METHODS

Using nationally representative community data from the National Comorbidity Survey, seven depression lifetime history subgroups were identified: one MDD screener symptom (n=1432); UsD (n=430); CsD (n=611); UMDD (n=182); and CMDD with 5-6 symptoms (n=518), 7 symptoms (n=217), and 8-9 symptoms (n=291). Severity was evaluated using five concurrent pathology validators: suicide attempt, interference with life, help seeking, hospitalization, and generalized anxiety disorder.

RESULTS

CsD validator levels are substantially higher than both UsD and UMDD levels, and similar to mild CMDD, disconfirming the "monotonicity thesis" that severity increase with symptom number. Complicated/uncomplicated status predicts severity, and when complicatedness is controlled, number of symptoms no longer predicts validator levels.

LIMITATIONS

Diagnoses were based on respondents' fallible retrospective symptom reports during a lay-administered structured interview, which may not yield diagnoses comparable to clinicians' assessments.

CONCLUSION

CsD is more severe than UsD and comparable to mild MDD. Complicated status more validly indicates depression severity than the standard number-of-symptoms measure.

The Age of Onset of Anxiety Disorders

OBJECTIVE

The objective was to estimate the age of onset (AOO) for all anxiety disorders and for specific subtypes. Gender differences in the AOO of anxiety disorders were examined, as were the influence of study characteristics on reported AOOs.

METHODS

Seven electronic databases were searched up to October 2014, with keywords representing anxiety disorder subtypes, AOO, and study design. The inclusion criteria were studies using a general population sample that provided data on the AOO for all anxiety disorders, or specific anxiety disorders, according to DSM-III-R, DSM-IV, or ICD-10 criteria.

RESULTS

There were 1028 titles examined, which yielded 24 studies meeting the inclusion criteria. Eight studies reported the AOO and gender. Meta-analysis found a mean AOO of all anxiety disorders of 21.3 years (95% CI 17.46 to 25.07). Separation anxiety disorder, specific phobia, and social phobia had their mean onset before the age of 15 years, whereas the AOO of agoraphobia, obsessive-compulsive disorder, posttraumatic stress disorder, panic disorder, and generalized anxiety disorder began, on average, between 21.1 and 34.9 years. Meta-analysis revealed no difference in the AOO between genders. A prospective study design and higher developmental level of the study country were associated with an earlier AOO.

CONCLUSIONS

Results from this meta-analysis indicate that anxiety disorder subtypes differ in the mean AOO, with onsets ranging from early adolescence to young adulthood. These findings suggest that prevention strategies of anxiety disorders should be directed towards factors associated with the development of anxiety disorder subtypes in the age groups with the greatest vulnerability for developing those disorders.

Psychological and Behavioral Issues in the Management of Migraine in Children and Adolescents

PURPOSE OF REVIEW

It is sometimes assumed that children and adolescents with migraine have a psychiatric or behavioral comorbidity, a belief that can be stigmatizing. This review will examine the recent literature addressing this area to determine if pediatric and adolescent migraineurs are at increased risk for psychiatric comorbidity and to discuss management strategies.

RECENT FINDINGS

A large systematic review of pediatric and adolescent studies concluded anxiety and depression were not associated with onset of recurrent headaches. Children with increasing migraine frequency have reduced school attendance. Pediatric migraineurs have mildly lower quality of life (QOL) scores than healthy peers but not abnormally low. Finally, children with higher migraine frequency as well as migraineurs with aura were more likely to report suicidal ideation. Migraine is a primary neurologic disorder. Migraine and psychiatric disorders may be comorbid; however, at this time, it can be difficult to clearly delineate some migraine features from psychiatric diagnoses with the current screening tools available. The majority of pediatric migraineurs do not have behavioral comorbidities; however, when such comorbidities occur, they should be addressed and appropriately managed. We need more accurate ways of delineating psychiatric and behavioral comorbidities from the migraine phenotype.

Predictors of remission from generalized anxiety disorder and major depressive disorder

BACKGROUND

The predictors of onset of major depressive disorder (MDD) and generalized anxiety disorder (GAD) are well-characterized. However the factors that predict remission from these conditions are less clear, and the study of this area is further complicated by differing definitions of remission.

METHODS

Data come from the National Comorbidity Survey - Replication, and analysis was limited to respondents with a lifetime history of GAD (n=621) or MDD (n=1299) assessed by the Composite International Diagnostic Interview. Predictors of remission included demographic factors, adverse childhood events, family history, and clinical characteristics. Multiple definitions of remission were explored to account for residual symptoms.

RESULTS

Half (54.4%) of respondents with MDD and 41.1% of respondents with GAD experienced full remission. Older age and higher socioeconomic status were positively related to remission in a dose-response manner for both disorders. Adverse childhood experiences and family history of anxious/depressive symptoms were negatively associated with remission from MDD. Comorbid GAD was inversely associated with remission from MDD (Odds ratio (OR): 0.62, 95% Confidence interval (CI): 0.44-0.88), but comorbid MDD did not impact remission from GAD (OR: 0.93, 95% CI: 0.64-1.35). With the exception of the influence of comorbidity, these associations were robust across definitions of remission.

LIMITATIONS

Cross-sectional analysis and retrospective recall of onset of MDD/GAD.

CONCLUSIONS

Many individuals with MDD or GAD will experience full remission. Some predictors appear to have a general association with remission from both disorders, while others are uniquely associated with remission from MDD.

Long noncoding RNAs: New evidence for overlapped pathogenesis between major depressive disorder and generalized anxiety disorder

BACKGROUND

About half of patients with major depressive disorder (MDD) have clinically meaningful levels of anxiety. Greater severity of depressive illness and functional impairment has been reported in patients with high levels of anxiety accompanying depression. The pathogenesis for the comorbidity was still unsure.

AIM

This study aimed to determine whether there would be molecular link for overlapped pathogenesis between MDD and anxiety disorder.

MATERIALS AND METHODS

Using long noncoding RNA (lncRNA) microarray profiling and reverse transcription polymerase chain reaction, six downregulated lncRNAs and three upregulated lncRNAs had been identified to be the potential biomarkers for MDD and generalized anxiety disorder (GAD), respectively. Then, the lncRNAs were cross-checked in forty MDD patients, forty GAD patients, and forty normal controls.

RESULTS

Compared with normal controls, six downregulated MDD lncRNAs also had a significantly lower expression in GAD (P < 0.01), and there was no significant difference between GAD and MDD (P > 0.05). In addition, three upregulated GAD lncRNAs had no different expression in MDD (P > 0.05), but there was remarkable difference between MDD and GAD (P < 0.01).

CONCLUSIONS

These results indicated that lncRNAs in peripheral blood mononuclear cells could be potential molecular link between MDD and GAD, which added new evidence to the overlapped pathogenesis and suggested that anxious depression could be a valid diagnostic subtype of MDD.

The Roles of Exercise and Yoga in Ameliorating Depression as a Risk Factor for Cognitive Decline

Currently, there are no effective pharmaceutical treatments to reduce cognitive decline or prevent dementia. At the same time, the global population is aging, and rates of dementia and mild cognitive impairment (MCI) are on the rise. As such, there is an increasing interest in complementary and alternative interventions to treat or reduce the risk of cognitive decline. Depression is one potentially modifiable risk factor for cognitive decline and dementia. Notably, exercise and yoga are two interventions known to both reduce symptoms of depression and improve cognitive function. The current review discusses the efficacy of exercise and yoga to ameliorate depression and thereby reduce the risk of cognitive decline and potentially prevent dementia. Potential mechanisms of change, treatment implications, and future directions are discussed.

Prevalence, correlates, comorbidity and severity of generalized anxiety disorder in Singapore

Despite its pervasiveness and associated impairment, generalized anxiety disorder (GAD) remains a poorly recognized disorder. Furthermore, given that GAD has been relatively understudied in Asia, the current study examined the prevalence, correlates and co-morbid conditions of this disorder in a multi-ethnic population of Singapore. Data was utilized from the Singapore Mental Health Study (SMHS), a cross-sectional epidemiological survey conducted among the adult population (n=6616) aged 18 years and above. The Composite International Diagnostic Interview version 3.0 (CIDI v3.0) was used to assess co-morbidity as well as the life-time and 12-month prevalence of disorders. Functional impairment and treatment-seeking behavior were also assessed. The life-time (0.9%) and 12-month (0.4%) prevalence estimates in the current study were found to be lower than those reported in Western populations but comparable to the prevalence estimates found in Asian countries. The relatively lower prevalence rate of GAD in this study suggests the possible role of culture in reporting and manifestation of anxiety symptomatology. The failure of a substantial proportion of individuals to seek treatment despite self-reported impairment was also identified as an area of concern.

Depression Narratives in Blogs: A Collaborative Quest for Coherence

People with depression often suffer from severe social seclusion, and the lack of an agreed upon etiology for depression makes it difficult to satisfactorily narrate and "ritually control" it. Focusing on blogs by women with major depression, I delineate the ways in which bloggers publicly express and collaboratively reconstruct their depression narratives. Specifically, using thematic analysis, I argue that depression blogs uniquely bridge between the seclusion that characterizes depression and the exposure offered in blogs, and thus offer people a rare opportunity to publicly share very intimate depression narratives, form communal bonds with their readers, and collaboratively revise their narratives. Depression blogs are also shown to function as "narrative sandboxes"-protected spaces in which bloggers can temporarily and experimentally add or remove different sections from their illness narratives, assess the compatibility of different cultural frameworks, and interchangeably use various metaphors, in an attempt to satisfactorily explain depression.

The underlying neurobiology of key functional domains in young people with mood and anxiety disorders: a systematic review

BACKGROUND

Mood and anxiety disorders are leading causes of disability and mortality, due largely to their onset during adolescence and young adulthood and broader impact on functioning. Key factors that are associated with disability and these disorders in young people are social and economic participation (e.g. education, employment), physical health, suicide and self-harm behaviours, and alcohol and substance use. A better understanding of the objective markers (i.e. neurobiological parameters) associated with these factors is important for the development of effective early interventions that reduce the impact of disability and illness persistence.

METHODS

We systematically reviewed the literature for neurobiological parameters (i.e. neuropsychology, neuroimaging, sleep-wake and circadian biology, neurophysiology and metabolic measures) associated with functional domains in young people (12 to 30 years) with mood and/or anxiety disorders.

RESULTS

Of the one hundred and thirty-four studies selected, 7.6 % investigated social and economic participation, 2.1 % physical health, 15.3 % suicide and self-harm behaviours, 6.9 % alcohol and substance use, whereas the majority (68.1 %) focussed on clinical syndrome.

CONCLUSIONS

Despite the predominance of studies that solely examine the clinical syndrome of young people the literature also provides evidence of distinct associations among objective measures (indexing various aspects of brain circuitry) and other functional domains. We suggest that a shift in focus towards characterising the mechanisms that underlie and/or mediate multiple functional domains will optimise personalised interventions and improve illness trajectories.

The nosologic relationship between generalized anxiety disorder and major depression

Generalized anxiety disorder (GAD) has undergone a series of revisions in its diagnostic criteria that has moved it, nosologically, away from its original affiliation with panic disorder (PD) and closer to major depressive disorder (MDD). This, together with its high comorbidity and putative shared genetic risk with MDD, has brought into question its place in future psychiatric nosology, prompting the planners of Diagnostic and Statistical Manual-V (DSM-V) and International Classification of Diseases-11 (ICD-11) to set up a workgroup tasked to better understand the relationship between GAD and MDD. This review attempts to summarize the extant data to compare GAD and MDD on a series of research validators to explore this relationship. Although insufficient data currently exist for GAD in several key validator classes, tentative conclusions can be drawn on the diagnostic status of GAD in relation to MDD. Although GAD possesses substantial overlap with MDD in the areas of genetics, childhood environment, demographics, and personality traits, this tends to hold true for other anxiety disorders (ADs) as well, with the strongest evidence for PD. Data from life events, personality disorders, biology, comorbidity, and pharmacology are mixed, showing some areas of similarity between GAD and MDD but some clear differences, again with a moderate degree of nonspecificity. Thus, although the bulk of evidence supports a close underlying relationship between them, the relatively nonspecific nature of these findings provides little more reason to question the nosologic validity of GAD in relation to MDD than that of some other anxiety disorders.

Genetic epidemiology of migraine and depression

Background

Migraine and major depressive disorder (commonly referred to as depression) are both common disorders with a significant impact on society. Studies in both clinical and community-based settings have demonstrated a strong relationship between migraine and depression. In addition to complicating the diagnosis, depression that is comorbid with migraine may lower treatment adherence, increase risk of medication overuse and is associated with migraine chronification, thus leading to higher direct and indirect costs and poorer health-related outcomes with increased disability.

Aim

The aim of this review is to summarise the current knowledge on the genetic epidemiology of migraine and depression and the possible biological mechanisms underlying their comorbidity.

Methods

We present a narrative review reporting on the current literature.

Results and conclusions

Epidemiological findings indicate that there is a bidirectional relationship between migraine and depression, with one disorder increasing the risk for the other and vice versa, suggesting shared biological mechanisms. Twin and family studies indicate that this bidirectional relationship can be explained, at least partly, by shared underlying genetically determined disease mechanisms. Although no genes have been robustly associated with the aetiology of both migraine and depression, genes from serotonergic, dopaminergic and GABAergic systems together with variants in the MTHFR and BDNF genes remain strong candidates.

Impact of Comorbid Depressive Disorders on Subjective and Physiological Responses to Emotion in Generalized Anxiety Disorder

Generalized anxiety disorder (GAD) and unipolar depressive disorders (UDD) have been shown to differ from each other in dimensions of affective functioning despite their high rates of comorbidity. We showed emotional film clips to a community sample (n = 170) with GAD, GAD with secondary UDD, or no diagnosis. Groups had comparable subjective responses to the clips, but the GAD group had significantly lower heart rate variability (HRV) during fear and after sadness, compared to controls. While HRV in the GAD and control groups rose in response to the sadness and happiness clips, it returned to baseline levels afterwards in the GAD group, potentially indicating lesser ability to sustain attention on emotional stimuli. HRV in the GAD + UDD group changed only in response to sadness, but was otherwise unvarying between timepoints. Though preliminary, these findings suggest comorbid UDD as a potential moderator of emotional responding in GAD.

Functional decline and herpes zoster in older people: an interplay of multiple factors

Herpes zoster is a frequent painful infectious disease whose incidence and severity increase with age. In older people, there is a strong bidirectional link between herpes zoster and functional decline, which refers to a decrement in ability to perform activities of daily living due to ageing and disabilities. However, the exact nature of such link remains poorly established. Based on the opinion from a multidisciplinary group of experts, we here propose a new model to account for the interplay between infection, somatic/psychiatric comorbidity, coping skills, polypharmacy, and age, which may account for the functional decline related to herpes zoster in older patients. This model integrates the risk of decompensation of underlying disease; the risk of pain becoming chronic (e.g. postherpetic neuralgia); the risk of herpes zoster non-pain complications; the detrimental impact of herpes zoster on quality of life, functioning, and mood; the therapeutic difficulties due to multimorbidity, polypharmacy, and ageing; and the role of stressful life events in the infection itself and comorbid depression. This model underlines the importance of early treatment, strengthening coping, and vaccine prevention.

ACF chromatin-remodeling complex mediates stress-induced depressive-like behavior

Improved treatment for major depressive disorder (MDD) remains elusive because of the limited understanding of its underlying biological mechanisms. It is likely that stress-induced maladaptive transcriptional regulation in limbic neural circuits contributes to the development of MDD, possibly through epigenetic factors that regulate chromatin structure. We establish that persistent upregulation of the ACF (ATP-utilizing chromatin assembly and remodeling factor) ATP-dependent chromatin-remodeling complex, occurring in the nucleus accumbens of stress-susceptible mice and depressed humans, is necessary for stress-induced depressive-like behaviors. We found that altered ACF binding after chronic stress was correlated with altered nucleosome positioning, particularly around the transcription start sites of affected genes. These alterations in ACF binding and nucleosome positioning were associated with repressed expression of genes implicated in susceptibility to stress. Together, our findings identify the ACF chromatin-remodeling complex as a critical component in the development of susceptibility to depression and in regulating stress-related behaviors.

The Relationship Between Early Maladaptive Schemas, Depression, and Generalized Anxiety among Adults Seeking Residential Treatment for Substance Use Disorders

Previous research has shown that early maladaptive schemas (EMS) play an important role in substance use, depression, and anxiety. However, few studies have examined the role of EMS within the context of all three concurrently. The goal of this study was to determine the role of EMS in predicting symptoms of Major Depressive Disorder (MDD) and Generalized Anxiety Disorder (GAD) among adults in residential treatment for substance dependence. We used pre-existing patient records of adults diagnosed with a substance use disorder from a residential substance use treatment facility (N=122). The EMS domains of disconnection and rejection and impaired limits were associated with symptoms of MDD and the domain of impaired autonomy and performance was associated with symptoms of GAD, even after controlling for age, gender, years of education, alcohol use, drug use, and symptoms of MDD (when predicting GAD) and GAD (when predicting MDD). Findings suggest that EMS may play an important role in comorbid mental health problems among men and women in residential substance use treatment. Continued treatment outcome research is needed to examine whether modification of EMS results in improved mental health and substance use outcomes.

Anxiety Assessment: Psychometric Properties of the Spanish Version of the Burns Anxiety Inventory

The main purpose of this study was to analyze the psychometric properties of the Spanish version of the Burns Anxiety Inventory (Burns-A: Burns, 1993). The sample consisted of 417 participants, 387 (29.71% male) healthy participants (control group: M = 35.5 years; SD = 8.40) and 30 (36.66% female) patients (clinical group: M = 35.8 years; SD = 12.94). The internal consistency evaluated through Cronbach' Alpha was 0.95 for the Total Score in both subsamples. The test-retest reliability (two weeks) for Total Score was 0.86 (F = 13.2, p ≤ .001) for the non-clinical subsample, and 0.95 (F = 36.5, p ≤ .001) for the clinical subsample. Confirmatory factor analyses supported the initial three-factor model. However, modifications to the initial three-factor model improved the goodness-of-fit indices. Results showed statistically significant differences in the mean scores of the Burns-A between the clinical and control groups. This study supports the Spanish version of the Burns-A as a brief and useful tool for the screening of anxiety symptoms in adult populations. Future studies should investigate measurement invariance across cultures.

Preschool anxiety disorders predict different patterns of amygdala-prefrontal connectivity at school-age

Objective

In this prospective, longitudinal study of young children, we examined whether a history of preschool generalized anxiety, separation anxiety, and/or social phobia is associated with amygdala-prefrontal dysregulation at school-age. As an exploratory analysis, we investigated whether distinct anxiety disorders differ in the patterns of this amygdala-prefrontal dysregulation.

Methods

Participants were children taking part in a 5-year study of early childhood brain development and anxiety disorders. Preschool symptoms of generalized anxiety, separation anxiety, and social phobia were assessed with the Preschool Age Psychiatric Assessment (PAPA) in the first wave of the study when the children were between 2 and 5 years old. The PAPA was repeated at age 6. We conducted functional MRIs when the children were 5.5 to 9.5 year old to assess neural responses to viewing of angry and fearful faces.

Results

A history of preschool social phobia predicted less school-age functional connectivity between the amygdala and the ventral prefrontal cortices to angry faces. Preschool generalized anxiety predicted less functional connectivity between the amygdala and dorsal prefrontal cortices in response to fearful faces. Finally, a history of preschool separation anxiety predicted less school-age functional connectivity between the amygdala and the ventral prefrontal cortices to angry faces and greater school-age functional connectivity between the amygdala and dorsal prefrontal cortices to angry faces.

Conclusions

Our results suggest that there are enduring neurobiological effects associated with a history of preschool anxiety, which occur over-and-above the effect of subsequent emotional symptoms. Our results also provide preliminary evidence for the neurobiological differentiation of specific preschool anxiety disorders.

[Affective disorders and anxiety comorbidities]

Anxiety disorders are frequently associated with affective disorders and represent one of the most important comorbidity in patients with bipolar disorder. Their prevalence is high, whatever the anxiety disorder, with nevertheless higher rates for generalized anxiety disorder (18.4 to 19.9% for lifetime prevalence). Such high frequencies raise essential questions about the link between these groups of disorders, and if it is necessary to distinguish them or to consider their phenomenological overlap as resulting of common disease processes. The existence of comorbid anxiety disorder in bipolar disorder significantly worsens its evolution, inducing more severe episodes, shortening remission periods, favoring relapses and suicide as well as substance use, and reducing quality of life in comparison to bipolar patients without anxiety. The mechanisms that link the anxious symptomatology to mood dysregulation are still poorly understood, although it is likely that genetic factors play a key role, combined with other factors of vulnerability, including those involved in coping strategy to address ongoing distress. Despite the high impact of anxiety on the severity of bipolar disorder course, few randomized controlled trials examined treatments of comorbid anxiety disorders and only recent recommendations offer useful therapeutic perspectives. In this context, it seems necessary to better understand the features associated with the occurence of anxiety disorders in affective disorders, in order to better identify the mechanisms underlying such comorbidity, together with working to develop therapeutics that efficiently target them.

Serotonin-prefrontal cortical circuitry in anxiety and depression phenotypes: pivotal role of pre- and post-synaptic 5-HT1A receptor expression

Decreased serotonergic activity has been implicated in anxiety and major depression, and antidepressants directly or indirectly increase the long-term activity of the serotonin system. A key component of serotonin circuitry is the 5-HT1A autoreceptor, which functions as the major somatodendritic autoreceptor to negatively regulate the "gain" of the serotonin system. In addition, 5-HT1A heteroreceptors are abundantly expressed post-synaptically in the prefrontal cortex (PFC), amygdala, and hippocampus to mediate serotonin actions on fear, anxiety, stress, and cognition. Importantly, in the PFC 5-HT1A heteroreceptors are expressed on at least two antagonist neuronal populations: excitatory pyramidal neurons and inhibitory interneurons. Rodent models implicate the 5-HT1A receptor in anxiety- and depression-like phenotypes with distinct roles for pre- and post-synaptic 5-HT1A receptors. In this review, we present a model of serotonin-PFC circuitry that integrates evidence from mouse genetic models of anxiety and depression involving knockout, suppression, over-expression, or mutation of genes of the serotonin system including 5-HT1A receptors. The model postulates that behavioral phenotype shifts as serotonin activity increases from none (depressed/aggressive not anxious) to low (anxious/depressed) to high (anxious, not depressed). We identify a set of conserved transcription factors including Deaf1, Freud-1/CC2D1A, Freud-2/CC2D1B and glucocorticoid receptors that may confer deleterious regional changes in 5-HT1A receptors in depression, and how future treatments could target these mechanisms. Further studies to specifically test the roles and regulation of pyramidal vs. interneuronal populations of 5-HT receptors are needed better understand the role of serotonin in anxiety and depression and to devise more effective targeted therapeutic approaches.

Serotonin transporter and BDNF polymorphisms interact to predict trait worry

BACKGROUND AND OBJECTIVES

Excessive worry is associated with a range of psychological disorders. While previous studies have examined genes associated with a range of different anxiety phenotypes, none have explored genes specifically associated with the general tendency to worry.

DESIGN

The present study tested associations between trait worry and functional polymorphisms of three candidate genes: the serotonin transporter-linked polymorphic region (5-HTTLPR) of the SLC6A4 gene, the Val66Met region of the brain-derived neurotrophic factor (BDNF) gene, and the Val158Met region of the catechol-O-methyltransferase (COMT) gene.

METHODS

A heterogeneous sample of adult participants (n=173) completed the Penn State Worry Questionnaire (PSWQ) and provided DNA samples for genotyping.

RESULTS

Results revealed a significant interaction between 5-HTTLPR and BDNF genotypes predicting levels of worry. Specifically, there was a significant positive association between 5-HTTLPR short alleles and PSWQ scores, but only in BDNF met allele carriers. COMT genotype was not significantly associated levels of worry, nor did COMT interact with 5-HTTLPR or BDNF genotypes to predict PSWQ scores.

CONCLUSIONS

These findings provide preliminary evidence about the putative genetic etiology of worrying. Key limitations of the present study and corresponding directions for future research on this topic are discussed.

Effects of comorbid anxiety disorders on the longitudinal course of pediatric bipolar disorders

OBJECTIVE

To examine the longitudinal effects of comorbid anxiety disorders in youth with bipolar spectrum disorder (BP).

METHOD

As part of the Course and Outcome of Bipolar Youth study, 413 youth, who were 7 through 17 years or age and who met criteria for DSM-IV BP-I (n = 244), BP-II (n = 28), and operationally defined bipolar disorder not otherwise specified (BP-NOS) (n = 141) were included. Subjects were followed on average 5 years using the Longitudinal Interval Follow-up Evaluation. Effects of anxiety on the time to mood recovery and recurrence and percentage of time with syndromal and subsyndromal mood symptomatology during the follow-up period were analyzed.

RESULTS

At intake and during the follow-up, 62% of youth with BP met criteria for at least 1 anxiety disorder. About 50% of the BP youth with anxiety had ≥2 anxiety disorders. Compared to BP youth without anxiety, those with anxiety had significantly more depressive recurrences and significantly longer median time to recovery. The effects of anxiety on recovery disappeared when the severity of depression at intake was taken into account. After adjusting for confounding factors, BP youth with anxiety, particularly those with ≥2 anxiety disorders, spent significantly less follow-up time asymptomatic and more time with syndromal mixed/cycling and subsyndromal depressive symptomatology compared to those without anxiety.

CONCLUSIONS

Anxiety disorders are common and adversely affect the course of BP in youth, as characterized by more mood recurrences, longer time to recovery, less time euthymic, and more time in mixed/cycling and depressive episodes. Prompt recognition and the development of treatments for BP youth with anxiety are warranted.

Sex differences in depressive, anxious behaviors and hippocampal transcript levels in a genetic rat model

Major depressive disorder (MDD) is a common, debilitating illness with high prevalence of comorbid anxiety. The incidence of depression and of comorbid anxiety is much higher in women than in men. These gender biases appear after puberty and their etiology is mostly unknown. Selective breeding of the Wistar Kyoto (WKY) rat strain, an accepted model of adult and adolescent depression, resulted in two fully inbred substrains. Adult WKY more immobile (WMI) rats of both sexes consistently show increased depression-like behavior in the forced swim test when compared with the control WKY less immobile (WLI) strain. In contrast, here we show that while adult female WMIs and WLIs both display high anxiety-like behaviors, only WLI males, but not WMI males, show this behavior. Moreover, the behavioral profile of WMI males is consistent from early adolescence to adulthood, but the high depression- and anxiety-like behaviors of the female WMIs appear only in adulthood. These sex-specific behavioral patterns are paralleled by marked sex differences in hippocampal gene expression differences established by genome-wide transcriptional analyses of 13th generation WMIs and WLIs. Moreover, sex- and age-specific differences in transcript levels of selected genes are present in the hippocampus of the current, fully inbred WMIs and WLIs. Thus, the contribution of specific genes and/or the influence of the gonadal hormonal environment to depression- and anxiety-like behaviors may differ between male and female WMIs, resulting in their distinct behavioral and transcriptomic profiles despite shared sequences of the somatic chromosomes.

Association analysis between the A118G polymorphism in the OPRM1 gene and treatment response to venlafaxine XR in generalized anxiety disorder

Patients diagnosed with generalized anxiety disorder (GAD) exhibit differential responses to standard antidepressant pharmacotherapy. Mounting evidence demonstrates that genetic differences may be implicated in treatment response in disorders like GAD. In this study, we examined whether the OPRM1 gene, which has been implicated in antidepressant treatment response in major depressive disorder, also has an effect in GAD. In our study, 156 patients diagnosed with GAD received venlafaxine XR treatment as part of an 18-month relapse prevention study. Genotypes were obtained for the OPRM1 functional variant A118G for the entire sample (n = 151); however, only the European American population was considered (n = 108) for pharmacogenetic analysis. We found no significant association between A118G and antidepressant treatment response in our GAD population. Future studies that include different single nucleotide polymorphisms of the OPRM1 gene as well as larger populations will need to be conducted to further elucidate the pharmacogenetic role of the endogenous opioid system in anxiety disorders.

β-endorphin modulates the effect of stress on novelty-suppressed feeding

Although stress is implicated in the pathophysiology of mood and anxiety disorders, not all individuals who suffer stressful life events develop psychopathology. Differential susceptibility to stress may be influenced by genetically mediated differences in hypothalamic-pituitary-adrenal (HPA) axis activity and moderation of the stress response by the opioid peptide β-endorphin (β-E). The present study investigated genetic contributions to coping behavior by examining anxious behavior of transgenic mice with varying capacities to synthesize β-E [B6.129S2-Pomc^tm1Low/J; regulated by insertion of a premature stop codon into one or both copies of the proopiomelanocortin (POMC) gene], both under normal conditions and following 3 min of forced swim (FS). Ten minutes after this stress exposure or a control manipulation, acutely food-deprived female and male transgenic mice were subjected to a novelty-suppressed feeding (NSF) test, during which their interaction with an almond slice located in the center of an open field box was measured. There was an interaction between genotype and stress for latency to approach the almond and whether or not the almond was approached, such that mice with low or absent β-E displayed a stronger aversion to novelty-feeding after stress exposure than did mice with normal levels. These data provide evidence for a moderating effect of β-E on the behavioral response to stress. Genotypic differences in anxious behavior emerged when mice were stressed prior to behavioral assessment, suggesting that β-E plays a role in coping behavior. These findings indicate that genetic variability in sensitivity of the β-E system to stress may contribute, at least in part, to heritable differences in stress reactivity as well as vulnerability to stress-related psychopathology.

Diagnostic overlap of generalized anxiety disorder and major depressive disorder in a primary care sample

BACKGROUND

Generalized anxiety disorder (GAD) and major depressive disorder (MDD) are highly comorbid. A possible explanation is that they share four symptoms according to the Diagnostic and Statistical Manual of Mental Disorders-Fourth Edition-Text Revision (DSM-IV-TR). The present study addressed the symptom overlap of people meeting DSM-IV-TR diagnostic criteria for GAD, MDD, or both to investigate whether comorbidity might be explained by overlapping diagnostic criteria.

METHODS

Participants (N = 1,218) were enrolled in the Coordinated Anxiety Learning and Management study (a randomized effectiveness clinical trial in primary care). Hypotheses were (1) the comorbid GAD/MDD group endorses the overlapping symptoms more than the nonoverlapping symptoms, and (2) the comorbid GAD/MDD group endorses the overlapping symptoms more than GAD only or MDD only groups, whereas differences would not occur for nonoverlapping symptoms.

RESULTS

The overlapping GAD/MDD symptoms were endorsed more by the comorbid group than the MDD group but not the GAD group when covarying for total symptom endorsement. Similarly, the comorbid group endorsed the overlapping symptoms more than the nonoverlapping symptoms and did not endorse the nonoverlapping symptoms more than the GAD or MDD groups when covarying for total symptom endorsement.

CONCLUSIONS

The results suggest that comorbidity of GAD and MDD is strongly influenced by diagnostic overlap. Results are discussed in terms of errors of diagnostic criteria, as well as models of shared psychopathology that account for diagnostic criteria overlap.

The 1-month prevalence of generalized anxiety disorder according to DSM-IV, DSM-V, and ICD-10 among nondemented 75-year-olds in Gothenburg, Sweden

OBJECTIVE

To examine the 1-month prevalence of generalized anxiety disorder (GAD) according to Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition (DSM-IV), Diagnostic and Statistical Manual of Mental, Fifth Edition (DSM-V), and International Classification of Diseases, Tenth Revision (ICD-10), and the overlap between these criteria, in a population sample of 75-year-olds. We also aimed to examine comorbidity between GAD and other psychiatric diagnoses, such as depression.

METHOD

During 2005-2006, a comprehensive semistructured psychiatric interview was conducted by trained nurses in a representative population sample of 75-year-olds without dementia in Gothenburg, Sweden (N = 777; 299 men and 478 women). All psychiatric diagnoses were made according to DSM-IV. GAD was also diagnosed according to ICD-10 and DSM-V.

RESULTS

The 1-month prevalence of GAD was 4.1% (N = 32) according to DSM-IV, 4.5% (N = 35) according to DSM-V, and 3.7% (N = 29) according to ICD-10. Only 46.9% of those with DSM-IV GAD fulfilled ICD-10 criteria, and only 51.7% and 44.8% of those with ICD-10 GAD fulfilled DSM-IV/V criteria. Instead, 84.4% and 74.3% of those with DSM-IV/V GAD and 89.7% of those with ICD-10 GAD had depression. Also other psychiatric diagnoses were common in those with ICD-10 and DSM-IV GAD. Only a small minority with GAD, irrespective of criteria, had no other comorbid psychiatric disorder. ICD-10 GAD was related to an increased mortality rate.

CONCLUSIONS

While GAD was common in 75-year-olds, DSM-IV/V and ICD-10 captured different individuals. Current definitions of GAD may comprise two different expressions of the disease. There was greater congruence between GAD in either classification system and depression than between DSM-IV/V GAD and ICD-10 GAD, emphasizing the close link between these entities.

Combination treatment with benzodiazepines and SSRIs for comorbid anxiety and depression: a review

OBJECTIVE

To review the literature on the co-occurrence of anxiety with depressive disorders and the rationale for and use of combination treatment with benzodiazepines and selective serotonin reuptake inhibitors/serotonin-norepinephrine reuptake inhibitors (SSRIs/SNRIs) for treating comorbid anxiety and depression.

DATA SOURCES

PubMed and PsycINFO were searched using terms identified as relevant based on existing practice guidelines. The primary search terms were anxiety, anxiety disorders, depression, depressive disorders, comorbidity, epidemiology, benzodiazepines, antidepressants, pharmacology, clinical trials, and pharmacotherapy. Reference lists of identified articles were also reviewed to ensure capture of relevant literature.

STUDY SELECTION

Publications were selected for inclusion in the review if they applied to adult populations and specifically addressed the comorbidity of anxiety and depression, their epidemiology, or their management. Case reports and case series were not considered for inclusion.

DATA EXTRACTION

Each author assessed the publications independently for content related to the review topics. Findings considered relevant to the clinical understanding and management of comorbid anxiety and depression were incorporated into the review.

DATA SYNTHESIS

Comorbidity is very common among patients with anxiety and depressive disorders, and, even when full criteria for 2 separate disorders are not met, subsyndromal symptoms are often present. Little controlled research has explored how benzodiazepines and SSRIs/SNRIs may be usefully combined, yet their combination is frequently employed in clinical practice. Patients with comorbidities are likely to have poorer treatment outcomes and have greater utilization of health care resources. Currently SSRIs/SNRIs are considered first-line therapy and are effective in both anxiety and depressive states. Nevertheless, many patients have only a partial response or have difficulty tolerating efficacious doses of antidepressant monotherapy. Benzodiazepines appear to improve treatment outcomes when an anxiety disorder co-occurs with depression or for depression characterized by anxious features. Specifically, they may provide benefits both in terms of speed of response and overall response.

CONCLUSIONS

Long-term management plans for anxiety disorder with or without comorbid depression should include strategies for acute or short-term care, long-term maintenance, and episodic or breakthrough symptoms. Combination therapy with benzodiazepines and antide-pressants in appropriate clinical settings may improve outcomes over monotherapy in some patients.

Patterns of co-morbidity with anxiety disorders in Chinese women with recurrent major depression

BACKGROUND

Studies conducted in Europe and the USA have shown that co-morbidity between major depressive disorder (MDD) and anxiety disorders is associated with various MDD-related features, including clinical symptoms, degree of familial aggregation and socio-economic status. However, few studies have investigated whether these patterns of association vary across different co-morbid anxiety disorders. Here, using a large cohort of Chinese women with recurrent MDD, we examine the prevalence and associated clinical features of co-morbid anxiety disorders.

METHOD

A total of 1970 female Chinese MDD patients with or without seven co-morbid anxiety disorders [including generalized anxiety disorder (GAD), panic disorder, and five phobia subtypes] were ascertained in the CONVERGE study. Generalized linear models were used to model association between co-morbid anxiety disorders and various MDD features.

RESULTS

The lifetime prevalence rate for any type of co-morbid anxiety disorder is 60.2%. Panic and social phobia significantly predict an increased family history of MDD. GAD and animal phobia predict an earlier onset of MDD and a higher number of MDD episodes, respectively. Panic and GAD predict a higher number of DSM-IV diagnostic criteria. GAD and blood-injury phobia are both significantly associated with suicidal attempt with opposite effects. All seven co-morbid anxiety disorders predict higher neuroticism.

CONCLUSIONS

Patterns of co-morbidity between MDD and anxiety are consistent with findings from the US and European studies; the seven co-morbid anxiety disorders are heterogeneous when tested for association with various MDD features.

Alterations of serotonin 2C and 2A receptors in response to T10 spinal cord transection in rats

Recent studies reported that a recovery of motoneurons after spinal cord transection at the sacrocaudal level may depend on adaptive alterations of the serotonin 2C (5-HT(2C)R) and 2A (5-HT(2C)R) receptor function via changes in mRNA editing or protein expression, respectively. It has been suggested that depletion of serotonergic input may drive these adaptations. Here, mRNA editing and/or expression of 5-HT(2C)R and 5-HT(2A)R was evaluated in rats that sustained a complete transection at the thoracic (T10) level. While 5-HT(2A)R mRNA expression was upregulated below the site of spinal cord injury (SCI), no changes in 5-HT(2C)R mRNA editing or expression were detected. These findings argue against the hypothesis that 5-HT(2C)R editing is regulated by extracellular serotonin levels. Rather, it appears that the editing process is just one of the ways in which excitability of motor neurons can be restored following SCI. To this end, the influence of excitatory locomotor circuits on motor neurons in the thoracic spinal cord of rats requires further exploration.

Contextual conditioning in rats as an animal model for generalized anxiety disorder

Animal models of psychiatric disorders are important translational tools for exploring new treatment options and gaining more insight into the disease. Thus far, there is no systematically validated animal model for generalized anxiety disorder (GAD), a severely impairing and difficult-to-treat disease. In this review, we propose contextual conditioning (CC) as an animal model for GAD. We argue that this model has sufficient face validity (there are several symptom similarities), predictive validity (it responds to clinically effective treatments), and construct validity (the underlying mechanisms are comparable). Although the refinement and validation of an animal model is a never-ending process, we want to give a concise overview of the currently available evidence. We suggest that the CC model might be a valuable preclinical tool to enhance the development of new treatment strategies and our understanding of GAD.