Relationship of anxiety and depression

Links between psychopathological symptoms and cortical thickness in men with severe alcohol use disorder: A Magnetic Resonance Imaging study

BACKGROUND

Anxiety and depression are psychopathological states frequently co-occurring with severe alcohol use disorder (SAUD). These symptoms generally disappear with abstinence but may persist in some patients, increasing the relapse risk.

METHODS

The cerebral cortex thickness of 94 male patients with SAUD was correlated with symptoms of depression and anxiety, both measured at the end (2-3 weeks) of the detoxification treatment. Cortical measures were obtained using surface-based morphometry implemented with Freesurfer.

RESULTS

Depressive symptoms were associated with reduced cortical thickness in the superior temporal gyrus of the right hemisphere. Anxiety level was correlated with lower cortical thickness in the rostral middle frontal region, inferior temporal region, and supramarginal, postcentral, superior temporal, and transverse temporal regions of the left hemisphere, as well as with a large cluster in the middle temporal region of the right hemisphere.

CONCLUSIONS

At the end of the detoxification stage, the intensity of depressive and anxiety symptoms is inversely associated with the cortical thickness of regions involved in emotions-related processes, and the persistence of the symptoms could be explained by these brain deficits.

Prevalence of depression and its association with quality of life among guardians of hospitalized psychiatric patients during the COVID-19 pandemic: a network perspective

Background

The COVID-19 pandemic has greatly affected treatment-seeking behaviors of psychiatric patients and their guardians. Barriers to access of mental health services may contribute to adverse mental health consequences, not only for psychiatric patients, but also for their guardians. This study explored the prevalence of depression and its association with quality of life among guardians of hospitalized psychiatric patients during the COVID-19 pandemic.

Methods

This multi-center, cross-sectional study was conducted in China. Symptoms of depression and anxiety, fatigue level and quality of life (QOL) of guardians were measured with validated Chinese versions of the Patient Health Questionnaire - 9 (PHQ-9), Generalized Anxiety Disorder Scale - 7 (GAD-7), fatigue numeric rating scale (FNRS), and the first two items of the World Health Organization Quality of Life Questionnaire - brief version (WHOQOL-BREF), respectively. Independent correlates of depression were evaluated using multiple logistic regression analysis. Analysis of covariance (ANCOVA) was used to compare global QOL of depressed versus non-depressed guardians. The network structure of depressive symptoms among guardians was constructed using an extended Bayesian Information Criterion (EBIC) model.

Results

The prevalence of depression among guardians of hospitalized psychiatric patients was 32.4% (95% CI: 29.7-35.2%). GAD-7 total scores (OR = 1.9, 95% CI: 1.8-2.1) and fatigue (OR = 1.2, 95% CI: 1.1-1.4) were positively correlated with depression among guardians. After controlling for significant correlates of depression, depressed guardians had lower QOL than non-depressed peers did [F_{(1, 1,101)} = 29.24, p < 0.001]. "Loss of energy" (item 4 of the PHQ-9), "concentration difficulties" (item 7 of the PHQ-9) and "sad mood" (item 2 of the PHQ-9) were the most central symptoms in the network model of depression for guardians.

Conclusion

About one third of guardians of hospitalized psychiatric patients reported depression during the COVID-19 pandemic. Poorer QOL was related to having depression in this sample. In light of their emergence as key central symptoms, "loss of energy," "concentration problems," and "sad mood" are potentially useful targets for mental health services designed to support caregivers of psychiatric patients.

Cross-lagged relationship between anxiety, depression, and sleep disturbance among college students during and after collective isolation

Object

Repeated quarantine policies over the past 3 years have led to poor psychological consequences for the public. Previous studies have proved that the quarantine policy leaves individuals vulnerable to anxiety, depression, and insomnia, especially among college students. This study aims to explore whether psychological problems during isolation continue with the release of isolation.

Methods

Overall, 2,787 college students both answered a web-based survey during and after the closure management was lifted. The Patient Health Questionnaire, Generalized Anxiety Disorder Scale, and Youth Self-rating Insomnia Scale were measured. The cross-lagged path model was used to explore the influence of psychological impact during isolation on the individual after the release.

Results

We found that anxiety and sleep disturbance levels alleviated significantly after quarantine, except for depression. As expected, a bidirectional relationship exists between anxiety, depression, and sleep disturbance. Moreover, depression and sleep disturbance can predict post quarantine depression, sleep disturbance, and anxiety, yet anxiety cannot predict sleep disturbance afterward.

Conclusion

Timely and effective intervention for anxiety, depression, and insomnia during isolation is essential for individuals to repair themselves quickly after the release.

Factors Affecting the Use of Social Networks and Its Effect on Anxiety and Depression among Parents and Their Children: Predictors Using ML, SEM and Extended TAM

Previous research has found support for depression and anxiety associated with social networks. However, little research has explored parents' depression and anxiety constructs as mediators that may account for children's depression and anxiety. The purpose of this paper is to test the influence of different factors on children's depression and anxiety, extending from parents' anxiety and depression in Jordan. The authors recruited 857 parents to complete relevant web survey measures with constructs and items and a model based on different research models TAM and extended with trust, analyzed using SEM, CFA with SPSS and AMOS, and ML methods, using the triangulation method to validate the results and help predict future applications. The authors found support for the structural model whereby behavioral intention to use social media influences the parent's anxiety and depression which correlate to their offspring's anxiety and depression. Behavioral intention to use social media can be enticed by enjoyment, trust, ease of use, usefulness, and social influences. This study is unique in exploring rumination in the context of the relationship between parent-child anxiety and depression due to the use of social networks.

Anxiety and Depression in Chinese Students During the COVID-19 Pandemic: A Meta-Analysis

Background: The novel 2019 coronavirus disease (COVID-19) pandemic has spread rapidly worldwide and poses a global health threat. Aims: This study assessed the prevalence of anxiety and depression symptoms in Chinese students during the COVID-19 pandemic and explored potential moderating factors. Methods: We searched English and Chinese databases using pertinent keywords for articles published and unpublished, up until November 2020. The estimate of the overall prevalence of anxiety and depression was conducted through a random-effects model. Results: A total of 31 cross-sectional studies were included. The overall prevalence of anxiety and depression symptoms in Chinese students during the COVID-19 pandemic was 24.0% (95% CI [20.0-29.0%]) and 22.0% (95% CI [18.0-27.0%]) respectively. Subgroup analyses revealed that Chinese middle school students were at heightened risk of anxiety, while university students were at heightened risk of depression. Students who lived in higher-risk areas presented severe anxiety and depression, especially during the late period of the COVID-19 epidemic. Conclusions: Overall, during the COVID-19 pandemic, there was a high prevalence of anxiety in Chinese students and a high prevalence of depression among Chinese students in high-risk areas. Therefore, comprehensive and targeted psychological interventions should be developed to address the mental health of students in different grades, especially in high-risk areas and during the late period of the COVID-19 pandemic.

Translating GWAS findings into therapies for depression and anxiety disorders: gene-set analyses reveal enrichment of psychiatric drug classes and implications for drug repositioning

BACKGROUND

Depression and anxiety disorders (AD) are the first and sixth leading causes of disability worldwide. Despite their high prevalence and significant disability resulted, there are limited advances in new drug development. Recently, genome-wide association studies (GWAS) have greatly advanced our understanding of the genetic basis underlying psychiatric disorders.

METHODS

Here we employed gene-set analyses of GWAS summary statistics for drug repositioning. We explored five related GWAS datasets, including two on major depressive disorder (MDD2018 and MDD-CONVERGE, with the latter focusing on severe melancholic depression), one on AD, and two on depressive symptoms and neuroticism in the population. We extracted gene-sets associated with each drug from DSigDB and examined their association with each GWAS phenotype. We also performed repositioning analyses on meta-analyzed GWAS data, integrating evidence from all related phenotypes.

RESULTS

Importantly, we showed that the repositioning hits are generally enriched for known psychiatric medications or those considered in clinical trials. Enrichment was seen for antidepressants and anxiolytics but also for antipsychotics. We also revealed new candidates or drug classes for repositioning, some of which were supported by experimental or clinical studies. For example, the top repositioning hit using meta-analyzed p values was fendiline, which was shown to produce antidepressant-like effects in mouse models by inhibition of acid sphingomyelinase.

CONCLUSION

Taken together, our findings suggest that human genomic data such as GWAS are useful in guiding drug discoveries for depression and AD.

Comorbidity of DSM–III–R Major Depressive Disorder in the General Population: Results from the US National Comorbidity Survey

General population data are presented on the prevalence and correlates of comorbidity between DSM–III–R major depressive disorder (MDD) and other DSM–III–R disorders. The data come from the US National Comorbidity Survey, a large general population survey of persons aged 15–54 years in the non-institutionalised civilian population. Diagnoses are based on a modified version of the Composite International Diagnostic Interview (CIDI). The analysis shows that most cases of lifetime MDD are secondary, in the sense that they occur in people with a prior history of another DSM–III–R disorder. Anxiety disorders are the most common primary disorders. The time-lagged effects of most primary disorders on the risk of subsequent MDD continue for many years without change in magnitude. Secondary MDD is, in general, more persistent and severe than pure or primary MDD. This has special public health significance because lifetime prevalence of secondary MDD has increased in recent cohorts, while the prevalence of pure and primary depression has remained unchanged.

Symptoms of Anxiety and Depression in Young Athletes Using the Hospital Anxiety and Depression Scale

Elite young athletes have to cope with multiple psychological demands such as training volume, mental and physical fatigue, spatial separation of family and friends or time management problems may lead to reduced mental and physical recovery. While normative data regarding symptoms of anxiety and depression for the general population is available (Hinz and Brähler, 2011), hardly any information exists for adolescents in general and young athletes in particular. Therefore, the aim of this study was to assess overall symptoms of anxiety and depression in young athletes as well as possible sex differences. The survey was carried out within the scope of the study "Resistance Training in Young Athletes" (KINGS-Study). Between August 2015 and September 2016, 326 young athletes aged (mean ± SD) 14.3 ± 1.6 years completed the Hospital Anxiety and Depression Scale (HAD Scale). Regarding the analysis of age on the anxiety and depression subscales, age groups were classified as follows: late childhood (12-14 years) and late adolescence (15-18 years). The participating young athletes were recruited from Olympic weight lifting, handball, judo, track and field athletics, boxing, soccer, gymnastics, ice speed skating, volleyball, and rowing. Anxiety and depression scores were (mean ± SD) 4.3 ± 3.0 and 2.8 ± 2.9, respectively. In the subscale anxiety, 22 cases (6.7%) showed subclinical scores and 11 cases (3.4%) showed clinical relevant score values. When analyzing the depression subscale, 31 cases (9.5%) showed subclinical score values and 12 cases (3.7%) showed clinically important values. No significant differences were found between male and female athletes (p ≥ 0.05). No statistically significant differences in the HADS scores were found between male athletes of late childhood and late adolescents (p ≥ 0.05). To the best of our knowledge, this is the first report describing questionnaire based indicators of symptoms of anxiety and depression in young athletes. Our data implies the need for sports medical as well as sports psychiatric support for young athletes. In addition, our results demonstrated that the chronological classification concerning age did not influence HAD Scale outcomes. Future research should focus on sports medical and sports psychiatric interventional approaches with the goal to prevent anxiety and depression as well as teaching coping strategies to young athletes.

Anxiety and depression in psychosis: a systematic review of associations with positive psychotic symptoms

OBJECTIVE

This review explores the influence of anxiety and depression on the experience of positive psychotic symptoms, and investigates the possibility of a causal role for anxiety and depression in the emergence and persistence of psychosis.

METHOD

A systematic literature search was undertaken, producing a number of papers which comment on the links between anxiety and depression, and the experience of delusions and hallucinations. In addition, evidence which could contribute to our understanding of the causal role of anxiety and depression was highlighted.

RESULTS

The findings show that both anxiety and depression are associated in meaningful ways with the severity of delusions and hallucinations, the distress they elicit and their content. However, the cross-sectional nature of the majority of studies and the focus on certain symptom subtypes tempers the validity of the findings. Data from non-clinical samples, studies which track the longitudinal course of psychosis and those which examine the impact of anxiety and depression on the prognosis for people experiencing psychosis, offer some support for the possibility of an influential role for anxiety and depression.

CONCLUSION

We conclude that anxiety and depression are related to psychotic symptom severity, distress and content and are also linked with sub-clinical experiences, symptom development, prognosis and relapse. These links may imply that anxiety and depression could be targets for therapeutic intervention. The article concludes with suggestions for further research, highlighting avenues which may circumvent the limitations of the body of work as it stands.

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.

Investigating differential symptom profiles in major depressive episode with and without generalized anxiety disorder: true co-morbidity or symptom similarity?

BACKGROUND

Large community-based epidemiological surveys have consistently identified high co-morbidity between major depressive episode (MDE) and generalized anxiety disorder (GAD). Some have suggested that this co-morbidity may be artificial and the product of the current diagnostic system. Because of the added direct and indirect costs associated with co-morbidity, it is important to investigate whether methods of diagnostic classification are artificially increasing the level of observed co-morbidity.

METHOD

The item response theory (IRT) log-likelihood ratio procedure was used to test for differential item functioning (DIF) of MDE symptoms between respondents with and without a diagnosis of GAD in the 2001-2002 National Epidemiological Survey on Alcohol and Related Conditions (NESARC).

RESULTS

The presence of GAD significantly increased the chances of reporting any symptom of MDE, with odds ratios ranging from 2.54 to 5.36. However, there was no indication of significant DIF of MDE symptoms in respondents with and without GAD.

CONCLUSIONS

The lack of any significant DIF indicates that cases with GAD do not present with a distinct MDE symptom profile, one that is consistent with the endorsement of symptoms that are conceptually similar in nature between the two disorders, compared to cases without GAD. This does not support the hypothesis that co-morbidity between MDE and GAD is artificially inflated because of the similar symptom criteria required by the current diagnostic system. Instead, MDE and GAD may be thought of as two distinct diagnostic entities that frequently co-occur because of a shared underlying trait.

Estimating ethnic differences in self-reported new use of antidepressant medications: results from the Multi-Ethnic Study of Atherosclerosis

INTRODUCTION

There is evidence that the utilization of antidepressant medications (ADM) may vary between different ethnic groups in the United States population.

METHODS

The Multi-Ethnic Study of Atherosclerosis (MESA) is a population-based prospective cohort study of 6814 US adults from 4 different ethnic groups. After excluding baseline users of ADM, we examined the relation between baseline depression and new use of ADM for 4 different ethnicities: African-Americans (n = 1822), Asians (n = 784) Caucasians (n = 2300), and Hispanics (n = 1405). Estimates of the association of ethnicity and ADM use were adjusted for age, study site, gender, Center for Epidemiologic Studies Depression Scale (CES-D), alcohol use, smoking, blood pressure, diabetes, education, and exercise. Non-random loss to follow-up was present and estimates were adjusted using inverse probability of censoring weighting (IPCW).

RESULTS

Of the four ethnicities, Caucasian participants had the highest rate of ADM use (12%) compared with African-American (4%), Asian (2%), and Hispanic (6%) participants. After adjustment, non-Caucasian ethnicity was associated with reduced ADM use: African-American (HR: 0.42; 95% Confidence Interval (CI): 0.31-0.58), Asian (HR: 0.14; 95%CI: 0.08-0.26), and Hispanic (HR: 0.47; 95%CI: 0.31-0.65). Applying IPCW to correct for non-random loss to follow-up among the study participants weakened but did not eliminate these associations: African-American (HR: 0.48; 95%CI: 0.30-0.57), Asian (HR: 0.23; 95%CI: 0.13-0.37), and Hispanic (HR: 0.58; 95%CI: 0.47-0.67).

CONCLUSION

Non-Caucasian ethnicity is associated with lower rates of new ADM use. After IPCW adjustment, the observed ethnicity differences in ADM use are smaller although still statistically significant.

Factor structure of the Japanese Interpersonal Competence Scale

AIM

Assessing social competence is important for clinical and preventive interventions of depression. The aim of the present paper was to examine the factor structure of the Japanese Interpersonal Competence Scale (JICS).

METHODS

Exploratory and confirmatory factor analysis was performed on the survey responses of 730 participants. Simultaneous multigroup analyses were conducted to confirm factor stability across psychological health status and sex differences.

RESULTS

Two factors, which represent Perceptive Ability and Self-Restraint, were confirmed to show a moderate correlation. Perceptive Ability involves a more cognitive aspect of social competence, while Self-Restraint involves a more behavioral aspect, both of which are considered to reflect the emotion-based relating style specific to the Japanese people: indulgent dependence (amae) and harmony (wa). In addition, Self-Restraint may be linked to social functioning. Both constructs may confound a respondent's perceived confidence.

CONCLUSION

Despite its shortcomings, the JICS is a unique measure of social competence in the Japanese cultural context.

Comorbid anxiety and depression: illumination of a controversy

Depression and anxiety frequently coexist in the same individual, either concurrently or at different times, and numerous studies show that the presence of an anxiety disorder is the single strongest risk factor for development of depression. When the two coexist simultaneously, either as diagnosed disorders or subsyndromal states, they may be viewed as mixed anxiety-depression or as comorbid syndromes, i.e. separate disorders occurring concurrently. Controversy continues over the nature of the relationship between depression and anxiety, some believing they are distinct, separate entities while others - now the majority - view them as overlapping syndromes that present at different points on a phenomenological and/or chronological continuum, and share a common neurobiology, the degree of overlap depending on whether each is described at the level of symptoms, syndrome or diagnosis. Community data likely underestimate true prevalence, since affected individuals frequently present in primary care with somatic, rather than psychological, complaints. Irrespective of the nature of the relationship, patients with both disorders experience significant vocational and interpersonal impairment, and more frequent recurrence, with greater likelihood of suicide, than individuals with single disorders. Various classes of antidepressant drugs offer symptom relief for these patients, the most selective of th SSRIs holding the greatest promise for sustained clinical improvement. Yet, the crucial parameter of successful pharmacotherapy seems to be the length of treatment, ensuring enhancement of the compromised neuroprotective and neuroplastic mechanisms. Further clarification of the relationship is a prerequisite for offering effective treatment to the many patients who experience lifetime depression and anxiety.

Recognizing the anxious face of depression

"Anxious depression" is used variably both by researchers and clinicians to describe admixtures of anxiety and depressive symptoms. The authors sought to determine the best model for conceptualizing anxious depression by studying a sample of depressed patients referred to a tertiary referral unit. Anxiety and depression were assessed using a comprehensive set of mixed symptoms that were subsequently refined to provide separate anxiety and depressive factors, and patients were trichotomized into groups of low, medium, and high anxiety on the basis of their total anxiety factor scores. Associations between the constructs of anxiety and depression in different depressive subgroups were explored, and the severity of depressive symptoms and other clinical variables across the three anxiety groupings was assessed. Depression variables were not linearly associated in a consistent pattern with anxiety-defined groups, arguing against a simple interdependence model driven by a higher-order variable such as depression severity. By contrast, the state anxiety categories were linked strongly with lifetime anxiety disorder prevalence, with some associations linear and with others evidencing a trend break association. The authors found support for a model of anxious depression, whereby anxiety both predisposes to nonmelancholic depression and contributes to its presentation by shaping its clinical features. Such a model and its definition assist in clarifying the cause of anxious depression and its treatment.

Effects of two-carbon bridge region methoxylation of benztropine: discovery of novel chiral ligands for the dopamine transporter

6-Methoxylated and 8-oxygenated benztropines were prepared and evaluated for their DAT and SERT activity (binding and uptake inhibition). Methoxylation at the two-carbon bridge of benztropine produced a novel class of potent and selective DAT ligands. An interesting enantioselectivity was also observed for this new class of chiral benztropines. The inactivity of the 8-oxygenated analogues seems to point out that, unlike cocaine and its analogues, interactions of benztropine ligands with DAT may be strongly governed by the nitrogen atom.

A convenient procedure for the synthesis of nonsymmetrical bivalent selective serotonin reuptake inhibitors using polymer-supported reagents

A convenient synthesis of nonsymmetrical bivalent inhibitors of the serotonin transporter is described. The synthesis utilizes polymer-supported reagents that allow for rapid access to novel bivalent ligands without the need for isolation or purification of synthetic intermediates.

Anxiety with depression: a treatment need

In the community, depression and anxiety are highly prevalent. The relationship between these two conditions is often unclear and has been the subject of much discussion. The classical viewpoint considered depression and anxiety to be two disorders with separate treatment options: anxiolytic agents for anxiety and antidepressant agents for depression. Depression and anxiety may occur together representing comorbid 'pure' conditions, or anxiety may predispose depression (or vice versa), or symptoms of anxiety and depression may be external manifestations of one underlying cause, or there may be an overlap of classifications. It is also possible that a mixed anxiety and depressive disorder exists: the association of subthreshold depressive symptoms and subthreshold depressive anxiety. This review examines the relationship of co-occurring depression and anxiety. The socioeconomic burden and the need for effective treatment of comorbid anxiety and depression are highlighted. The SSRIs, e.g. paroxetine, are discussed in particular as appropriate pharmacological therapy for anxiety with depression.

The serotonergic and noradrenergic systems of the hippocampus: their interactions and the effects of antidepressant treatments

Previous reviews have well illustrated how antidepressant treatments can differentially alter several neurotransmitter systems in various brain areas. This review focuses on the effects of distinct classes of antidepressant treatments on the serotonergic and the noradrenergic systems of the hippocampus, which is one of the brain limbic areas thought to be relevant in depression: it illustrates the complexity of action of these treatments in a single brain area. First, the basic elements (receptors, second messengers, ion channels, ...) of the serotonergic and noradrenergic systems of the hippocampus are revisited and compared. Second, the extensive interactions occurring between the serotonergic and the noradrenergic systems of the brain are described. Finally, issues concerning the short- and long-term effects of antidepressant treatments on these systems are broadly discussed. Although there are some contradictions, the bulk of data suggests that antidepressant treatments work in the hippocampus by increasing and decreasing, respectively, serotonergic and noradrenergic neurotransmission. This hypothesis is discussed in the context of the purported function of the hippocampus in the formation of memory traces and emotion-related behaviors.

Changes in Behaviour and Body Weight Following a Single or Double Social Defeat in Rats

In a series of experiments, the consequences of a single and double social conflict on various behaviours and body weight in rats were studied. Animals were subjected to social defeat by placing them into the territory of an aggressive male conspecific for one hour, either once, or twice at the same time on two consecutive days. To assess the consequences of social defeat, three experiments were performed with independent groups of rats. In the first experiment, an open field test was performed two days after the last conflict. Locomotor activity was strongly reduced after social defeat. There were no differences between the single and double defeat group. To assess the effects of social defeat on subsequent social behaviour, a second experiment was performed in which experimental animals were confronted with an unfamiliar non-aggressive rat two days after a single or double conflict. Social defeat resulted in a reduction of social contact with the unfamiliar conspecific. There was no difference between the single and double conflict group. In the third experiment, the effects of social conflict on food intake, body weight and saccharine preference were measured. Food intake was not affected after a single conflict, but in the double conflict group food intake was decreased for several days. Body weight gain was decreased after both single and double social defeat. The decrease was stronger in the double conflict group. Water intake and saccharine preference were not significantly affected. This study revealed that social defeat in rats causes pronounced changes in various behaviours and body weight. Different aspects of behaviour are differentially affected by defeat with respect to the magnitude and time course of the changes induced. Moreover, different behavioural parameters are differentially sensitive to repetition of the stressor.

Effects of two stressors on behaviour in the elevated X-maze: preliminary investigation of their interaction with 8-OH-DPAT

Effects of water deprivation and restraint were compared in the rat elevated X-maze. Water deprivation for 12-48 h increased corticosterone and had a duration-dependent "anxiolytic" effect in the elevated X-maze, increasing the ratio of open/total arm entries (OTR) and the proportion of time spent on the open arms (% time) without affecting total entries. Brain 5HIAA/5HT was increased only after 24 or 48 h deprivation. Restraint for 15 min also increased plasma corticosterone and brain 5HIAA/5HT but had no effect on behaviour in the elevated X-maze when rats were tested immediately afterwards. However, 1 h restraint was "anxiogenic" in the elevated X-maze immediately after release, reducing OTR and % time, but with a less consistent reduction in total entries; reductions in OTR and % time were still present 24 h later. The 5HT1A agonist 8-hydroxy-2-(di-n-propylamino) tetralin (8-OH-DPAT) (0.1-0.2 mg/kg), administered 10 min before testing in the elevated X-maze, had "anxiogenic" actions in non-stressed rats. The effect of 0.1 mg/kg 8-OH-DPAT was not significantly altered by 24 or 48 h water deprivation but was abolished by restraint for 1 h immediately beforehand, despite the "anxiogenic" effect of restraint alone. Similar mutual antagonism of 8-OH-DPAT and restraint occurred when the dose of 8-OH-DPAT was increased to 0.2 mg/kg. Twenty-four hours after restraint, restrained rats which had received 8-OH-DPAT (0.1-0.2 mg/kg) still did not show any significant "anxiogenic effect" compared with non-restrained vehicle treated controls. Restraint-induced deficits in elevated X-maze exploration may prove a useful model with which to study the pharmacology of depression-related anxiety. However, the effects of the stressors examined, and their interaction with 8-OH-DPAT in the elevated X-maze, appear to depend on the nature of the stressor.