Bipolar Disorder

Temporal Directionality Between Symptoms During Treatment of Depressed Inpatients: A Dynamic Time Warp Network Analysis

BACKGROUND

Depression is generally perceived from the perspective of the common-cause disease model. However, the network perspective assumes mutual influence of individual symptoms and stresses the importance of investigating symptom dynamics. Gaining a better understanding of symptom dynamics within individuals might contribute to more effective treatments.

METHODS

Current exploratory longitudinal research studied the associations and directionality between 43 symptoms from the generic questionnaire Symptom Questionnaire-48 (SQ-48) using dynamic time warp (DTW) analyses, in which trajectories with similar time-dependent patterns can be identified. Data from individuals were analysed first, yielding distance matrices for all symptom trajectories, after which the data were aggregated.

RESULTS

The 148 included patients were all admitted for the treatment of their clinical depression. Undirected DTW analyses of three patients with longer time series but otherwise randomly chosen showed large variability among individuals. Group-level undirected DTW analyses showed numerous significant edges between symptoms, largely clustering symptoms according to the eight pre-existing subscales of the SQ-48. Group-level directed DTW analyses showed five symptoms with significant outstrength: 'hopeless', 'restless', 'down/depressed', 'feeling tense' and 'no enjoyment', meaning that change in these key symptoms preceded change in other symptoms.

LIMITATIONS

The 43 included symptoms of the SQ-48 primarily focus on internalizing problems in severely depressed inpatients, potentially limiting generalizability.

CONCLUSIONS

DTW networks provided us with five key symptoms based on the dynamics of symptom scores. Future studies could explore whether process-based therapy targeted at symptoms with high outstrength might result in more effectivity as part of personalized treatment.

The role of metabolic syndrome as a mediator in the relationship between CCL11 levels and the presence of a mood episode with mixed features in young adults with bipolar disorder

Mixed features presentation in bipolar disorder (BD) represents the most severe form of the disease. BD may lead to cognitive and functional deterioration, a process known as neuroprogression, which appears to be exacerbated by increased serum levels of CCL11, a neuroprogression-related cytokine. Metabolic syndrome (MetS) is highly prevalent in BD, and it is known that the presence of MetS may increase inflammation, which may contribute to increased CCL11 levels, and consequently impact on the severity of the disorder. What is not known is whether the MetS mediates the association between CCL11 levels and the presence of mood episodes with mixed features in BD. Therefore, the aim of this study was to investigate the mediating effect of MetS on the relationship between CCL11 levels and the presence of mood episodes with mixed features in BD, in a population-based study. This is a cross-sectional study that included 184 young adults, 92 with BD and 92 populational controls, matched by sex and age. BD diagnosis was assessed using the Mini International Neuropsychiatric Interview - PLUS. Mood episodes with mixed features was defined according to DSM-IV and DSM-5 criteria. MetS was defined according to the National Cholesterol Education Program (NCEP/ATP III). Substance use was assessed through the Alcohol, Smoking and Substance Involvement Screening Test (ASSIST). CCL11 serum levels were analyzed using the multiplex analysis method Luminex 200™ system. The mediation model was tested using the MedMod module of the JAMOVI 2.4.8 software. Mediation analysis indicated a trend towards significance of MetS mediating the association between CCL11 and the presence of a mood episode with mixed features in BD (p = 0.065). Individuals with BD presenting with a mood episode with mixed features and MetS may have accelerated neuroprogression due to the influence of MetS on CCL11 levels, therefore, assessing for MetS occurrence in this population and implementing early interventions to prevent its development may be effective ways of delaying cognitive impairments related to this cytokine.

Sex Differences in Brain Disorders

A remarkable feature of the brain is its sexual dimorphism. Sexual dimorphism in brain structure and function is associated with clinical implications documented previously in healthy individuals but also in those who suffer from various brain disorders. Sex-based differences concerning some features such as the risk, prevalence, age of onset, and symptomatology have been confirmed in a range of neurological and neuropsychiatric diseases. The mechanisms responsible for the establishment of sex-based differences between men and women are not fully understood. The present paper provides up-to-date data on sex-related dissimilarities observed in brain disorders and highlights the most relevant features that differ between males and females. The topic is very important as the recognition of disparities between the sexes might allow for the identification of therapeutic targets and pharmacological approaches for intractable neurological and neuropsychiatric disorders.

Functional Connectivity of the Anterior Cingulate Cortex and the Right Anterior Insula Differentiates between Major Depressive Disorder, Bipolar Disorder and Healthy Controls

Background: This study aimed to explore possible differences of the whole-brain functional connectivity of the anterior cingulate cortex (ACC) and anterior insula (AI), in a sample of depressed patients with major depressive disorder (MDD), bipolar disorder (BD) and healthy controls (HC). Methods: A hundred and three subjects (n_MDD = 35, n_BD = 25, and n_HC = 43) between the ages of eighteen and sixty-five years old underwent functional magnetic resonance imaging. The CONN Toolbox was used to process and analyze the functional connectivity of the ACC and AI. Results: The comparison between the patients (MDD/BD) and HC yielded increased resting-state functional connectivity (rsFC) between the ACC and the motor and somatosensory cortices (SSC), superior parietal lobule (SPL), precuneus, and lateral occipital cortex, which was driven by the BD group. In addition, hyperconnectivity between the right AI and the motor and SSC was found in BD, as compared to HC. In MDD, as compared to HC, hyperconnectivity between ACC and SPL and the lateral occipital cortex was found, with no statistical rsFC differences for the AI seed. Compared to BD, the MDD group showed ACC-cerebellum hyperconnectivity and a trend for increased rsFC between the right AI and the bilateral superior frontal cortex. Conclusions: Considering the observed hyperconnectivity between the ACC/somatosensory cortex in the patient group, we suggest depression may be related to an impairment of the sensory-discriminative function of the SSC, which results in the phenomenological signature of mental pain in both MDD and BD. These findings suggest that future research should investigate this particular network with respect to motor functions and executive control, as a potential differential diagnostic biomarker for MDD and BD.

Neurovascular alterations in bipolar disorder: A review of perfusion weighted magnetic resonance imaging studies

BACKGROUND

Bipolar Disorder (BD) is a severe chronic psychiatric disorder whose aetiology is still largely unknown. However, increasing literature reported the involvement of neurovascular factors in the pathophysiology of BD, suggesting that a measure of Cerebral Blood Flow (CBF) could be an important biomarker of the illness. Therefore, since, to date, Magnetic Resonance Perfusion Weighted Imaging (PWI) techniques, such as Dynamic Susceptibility Contrast (DSC) and Arterial Spin Labelling (ASL), are the most common approaches that allow non-invasive in-vivo perfusion measurements,this review aims to summarize the results from all PWI studies that evaluated the CBF in BD.

METHODS

A bibliographic search in PubMed up until May 2021 was performed. 16 PWI studies that used DSC or ASL sequences met our inclusion criteria.

RESULTS

Overall, the results supported the presence of hyper-perfusion in the cingulate cortex and fronto-temporal regions, as well as the presence of hypo-perfusion in the cerebellum in BD, compared with both healthy controls and patients with unipolar depression. CBF changes after cognitive and aerobic training, as well as in relation with other physiological, clinical, and neurocognitive variables were also reported.

LIMITATIONS

The heterogeneity across the studies, in terms of experimental designs, sample selection, and methodological approach employed, limited the studies' comparison.

CONCLUSIONS

These findings showed CBF alterations in the cingulate cortex, fronto-temporal regions, and cerebellum in BD, suggesting that CBF may be an important pathophysiological marker of BD that merits further investigation to clarify the extent of neurovascular alterations.

An Experimental Study to Assess the Professional and Social Consequences of Tardive Dyskinesia

OBJECTIVE

Antipsychotic medications may cause tardive dyskinesia (TD), an often-irreversible movement disorder characterized by involuntary movements that are typically stereotypic, choreiform, or dystonic and may impair quality of life. This study evaluated others' perceptions of abnormal TD movements in professional and social situations.

METHODS

This was an experimental, randomized, blinded, digital survey in a general population sample. Participants were randomized 1:1 into a test or control group to view a video of a professional actor simulating TD movements or no TD movements prior to completing surveys on employment, dating, and friendship domains. Assessments for mild-to-moderate and moderate-to-severe TD movements were conducted separately. Authenticity of abnormal movements and Abnormal Involuntary Movement Scale (AIMS) scores were evaluated by physician experts.

RESULTS

Surveys were completed by 2,400 participants each for mild-to-moderate and moderate-to-severe TD. In all domains, participants responded significantly less favorably to persons with TD movements (both mild-to-moderate and moderate-to-severe) than those without TD movements. Fewer participants in the test versus control group for mild-to-moderate and moderate-to-severe TD, respectively, considered the candidate as a potential employee (29.2% and 22.7% fewer), found him/her attractive (20.5% and 18.7% fewer), and were interested in becoming friends with him/her (12.3% and 16.5% fewer).

CONCLUSION

Professional actors simulating TD movements were perceived more negatively than those without TD movements in employment, dating, and friendship domains. To our knowledge, this is the first randomized study to quantify professional and social stigma associated with TD movements that may reduce opportunities for gainful employment, marital status, and an effective support system.

GABRB2, a key player in neuropsychiatric disorders and beyond

The GABA receptors represent the main inhibitory system in the central nervous system that ensure synaptogenesis, neurogenesis, and the regulation of neuronal plasticity and learning. GABAA receptors are pentameric in structure and belong to the Cys-loop superfamily. The GABRB2 gene, located on chromosome 5q34, encodes the β2 subunit that combines with the α and γ subunits to form the major subtype of GABAA receptors, which account for 43% of all GABAA receptors in the mammalian brain. Each subunit probably consists of an extracellular N-terminal domain, four membrane-spanning segments, a large intracellular loop between TM3 and TM4, and an extracellular C-terminal domain. Alternative splicing of the RNA transcript of the GABRB2 gene gives rise at least to four long and short isoforms with dissimilar electrophysiological properties. Furthermore, GABRB2 is imprinted and subjected to epigenetic regulation and positive selection. It has been associated with schizophrenia first in Han Chinese, and subsequently validated in other populations. Gabrb2 knockout mice also exhibited schizophrenia-like behavior and neuroinflammation that were ameliorated by the antipsychotic drug risperidone. GABRB2 was also associated with other neuropsychiatric disorders including bipolar disorder, epilepsy, autism spectrum disorder, Alzheimer's disease, frontotemporal dementia, substance dependence, depression, internet gaming disorder, and premenstrual dysphoric disorder. Recently, it has been postulated that GABRB2 might be a potential marker for different cancer types. As GABRB2 has a pivotal role in the central nervous system and is increasingly recognized to contribute to human diseases, further understanding of its structure and function may expedite the generation of new therapeutic approaches.

Internalized-stigma and dissociative experiences in bipolar disorder

INTRODUCTION

Dissociative symptoms have been recently related to bipolar disorder (BD) symptomatology. Moreover, the disease burden carries on a share of perceived self-stigma that amplifies the BD impairment. Internalized stigma and dissociative symptoms often seem overlapping, leading toward common outcomes, with reduced treatment seeking and poor adherence. We hypothesize a potential relationship between dissociation and self-stigma in patients suffering from BD.

MATERIALS AND METHODS

In this cross-sectional study we enrolled a total of 120 adult clinically stable BD outpatients. All participants completed the Internalized Stigma of Mental Illness (ISMI), Dissociative Experiences Scale-II (DES-II), and Manchester Short Assessment of Quality of Life (MANSA).

RESULTS

Average age and age at BD (BD-I n = 66, 55%; BD-II n = 54, 45%) onset were 46.14 (±4.23), and 27.45 (±10.35) years, with mean disease duration of 18.56 (±13.08) years. Most participants were female (n = 71; 59.2%) and 40 (33%) of them experienced lifetime abuse, with an average of 1.05 (±0.78) suicide attempts. DES scores (mean 31.8, ±21.6) correlated with ISMI total-score, with significant association with spikes in Alienation (13.1, SD±3.1) (p < 0.001) and Stereotype (13.8, SD±3.9) (p < 0.001). Linear regression analysis has shown a significant association between DES total score and alienation (p < 0.001), stereotype (p < 0.001) and MANSA total-score (p < 0.001).

DISCUSSION

For the first time, our data suggests that self-stigma is associated to dissociative symptoms, reducing overall quality of life in BD. The early identification of at-risk patients with previous lifetime abuse and high perceived stigma could lead the way for an ever more precise tailoring of treatment management.

Sex Differences in Bipolar Disorders: Impact on Psychopathological Features and Treatment Response

INTRODUCTION

Sex differences were demonstrated in bipolar disorders (BD) concerning epidemiological, clinical, and psychopathological characteristics, but consensus is lacking. Moreover, data concerning the influence of sex on treatment response in BD is contrasting. The present cross-sectional study aimed to analyze sex differences in a population of BD subjects, with specific focus on psychopathological features and treatment response.

MATERIALS AND METHODS

Subjects diagnosed with BD according to the Diagnostic and Statistical Manual of Mental Disorders, 5th version (DSM-5) were recruited. Socio-demographic and clinical characteristics were collected. The Hamilton Rating Scale for Depression, the Mania Rating Scale (MRS), the brief version of the Temperament Evaluation of Memphis, Pisa and San Diego-Münster version (briefTEMPS-M), and the Barratt Impulsiveness Scale-11 items (BIS-11) were used for psychopathological assessment. Treatment response was appraised with the Alda Scale. We performed bivariate analyses to compare socio-demographic, clinical, and psychopathological characteristics between men and women (p < 0.05). A logistic regression was run to analyze features that were significantly associated with female sex.

RESULTS

Among the recruited 219 BD subjects, 119 (54.3%) were females. Women had a lower scholarity (p = 0.015) and were less frequently employed (p = 0.001). As for psychopathological features, a higher MRS total score (p < 0.001) was detected among women, as well as higher BIS-11 total score (p = 0.040), and briefTEMPS-M score for anxious temperament (p = 0.006). Men showed higher prevalence of DSM-5 mixed features (p = 0.025), particularly during a depressive episode (p = 0.014). Women reported longer duration of untreated illness (DUI) (p < 0.001). There were no sex differences in the Alda Scale total score when considering the whole sample, but this was significantly higher among men (p = 0.030) when evaluating subjects treated with anticonvulsants. At the logistic regression, female sex was positively associated with longer DUI (p < 0.001; OR 1.106, 95% CI 1.050-1.165) and higher MRS total score (p < 0.001; OR 1.085, 95% CI 1.044-1.128) and negatively associated with employment (p = 0.003; OR 0.359, 95% CI 0.185-0.698) and DSM-5 mixed features (p = 0.006; OR 0.391, 95% CI 0.200-0.762).

CONCLUSIONS

The clinical presentation of BD may differ depending on sex. The severity of BD should not be neglected among women, who may also display worse treatment response to anticonvulsants.

Mood Stabilizers in Psychiatric Disorders and Mechanisms Learnt from In Vitro Model Systems

Bipolar disorder (BD) and schizophrenia are psychiatric disorders that manifest unusual mental, behavioral, and emotional patterns leading to suffering and disability. These disorders span heterogeneous conditions with variable heredity and elusive pathophysiology. Mood stabilizers such as lithium and valproic acid (VPA) have been shown to be effective in BD and, to some extent in schizophrenia. This review highlights the efficacy of lithium and VPA treatment in several randomized, controlled human trials conducted in patients suffering from BD and schizophrenia. Furthermore, we also address the importance of using induced pluripotent stem cells (iPSCs) as a disease model for mirroring the disease's phenotypes. In BD, iPSC-derived neurons enabled finding an endophenotype of hyperexcitability with increased hyperpolarizations. Some of the disease phenotypes were significantly alleviated by lithium treatment. VPA studies have also reported rescuing the Wnt/β-catenin pathway and reducing activity. Another significant contribution of iPSC models can be attributed to studying the molecular etiologies of schizophrenia such as abnormal differentiation of patient-derived neural stem cells, decreased neuronal connectivity and neurite number, impaired synaptic function, and altered gene expression patterns. Overall, despite significant advances using these novel models, much more work remains to fully understand the mechanisms by which these disorders affect the patients' brains.

Precursors of self-reported subclinical hypomania in adolescence: A longitudinal general population study

Symptoms of subclinical hypomania (SHM) are common in the general population of adolescents and young adults. SHM are most often transient yet might be risk markers of later bipolar disorder. The current study aimed to assess the clinical correlates of SHM at age 11 in the general population, examine the continuity of SHM from age 11-age 16 and explore the clinical precursors of age 16 SHM. As part of the Copenhagen Child Cohort 2000, 1,632 preadolescents participated in the examination of SHM and various clinical correlates at age 11, 893 were re-assessed for SHM at age 16 years. At age 11, SHM, psychotic experiences and depressive symptoms were assessed by semi-structured psychopathological interviews. Furthermore, the participants were diagnostically assessed by the Development and Well-Being Assessment and interviewed about sleep length. At age 16, SHM was assessed by self-report, using the Hypomania Checklist-32. Cannabis use occurring at age 15 or earlier was assessed at age 16. At age 11, SHM was associated with depressive disorders (Relative Risk [RR] = 2.96 [95% CI 1.26–6.96]), interview-based depressive symptoms (RR = 9.22 [5.93–14.34]), neurodevelopmental disorders (RR = 2.94 [1.66–5.20]), psychotic experiences (RR = 4.51 [2.90–7.01]) and insufficient sleep (RR = 2.10 [1.28–3.43]. In the longitudinal analyses, age 16 SHM was preceded by age 11 SHM (RR = 1.89 [1.02–3.49]), psychotic experiences (RR = 2.06, [1.28–3.33]), emotional disorders (RR = 1.77, [1.02–3.09]) and cannabis use (RR = 3.14, [1.93–5.10]), after mutual adjustment and adjustment for sex, and sociodemographic factors. In conclusion, age 11 SHM was statistically significantly associated with other types of psychopathology in cross-sectional analyses and showed some continuity with later self-reported SHM at age 16. Particularly early psychotic experiences and cannabis use stood out as independent precursors of self-reported SHM and might constitute important risk markers for the development of future SHM and bipolar disorder. An important potential caveat of the current study includes the self-report assessment of SHM.

Pharmacogenetics of Carbamazepine and Valproate: Focus on Polymorphisms of Drug Metabolizing Enzymes and Transporters

Pharmacogenomics can identify polymorphisms in genes involved in drug pharmacokinetics and pharmacodynamics determining differences in efficacy and safety and causing inter-individual variability in drug response. Therefore, pharmacogenomics can help clinicians in optimizing therapy based on patient's genotype, also in psychiatric and neurological settings. However, pharmacogenetic screenings for psychotropic drugs are not routinely employed in diagnosis and monitoring of patients treated with mood stabilizers, such as carbamazepine and valproate, because their benefit in clinical practice is still controversial. In this review, we summarize the current knowledge on pharmacogenetic biomarkers of these anticonvulsant drugs.

Clinical Impact of Psychopathy on Bipolar Disorder

Background and Objectives. Bipolar disorder (BD) is associated with a significant burden due to affective symptoms and behavioral manifestations, but also cognitive and functional impairment. Comorbidity with other psychiatric conditions, including personality disorders, is frequent. The comorbidity with psychopathy deserves special consideration given that both disorders share some clinical characteristics, such as grandiosity, risky behavior or poor insight, among others, that can worsen the outcome of BD. Therefore, this study aimed to evaluate the prevalence of psychopathy in a sample of clinically stabilized patients with BD and its impact on the severity of BD. Materials and Methods. A sample of 111 patients with BD (38 type I and 73 type II) was studied. The Hamilton Depression Rating Scale (HAM-D) and the Young Mania Rating Scale (YMRS) served to assess the severity of BD. Psychopathy was measured by means of the Psychopathic Personality Inventory-Revised (PPI-R). Patients were divided into three groups according to the severity of psychopathy (Group 1: no psychopathy; Group 2: “psychopathic” trait; Group 3: clinical psychopathy). Other measures regarded impulsiveness (Barratt Impulsiveness Scale-11, BIS-11) and empathy (Empathy Quotient, EQ). Comparisons of mania, depression, impulsivity and empathy scores were run with MANOVA considering psychopathy and diagnosis as independent variables. Results. The prevalence of psychopathy was 5.4%. A significant association between the level of psychopathy and YMRS, attentional/cognitive impulsivity and motor impulsivity scores emerged. No interaction between psychopathy and BD diagnosis was found. Post hoc analysis demonstrated significantly higher YMRS scores in Group 3 than in Group 1; that is, patients with psychopathy have more manic symptoms. Conclusion. Psychopathy seems quite frequent among patients with BD. The association of psychopathy with BD results in higher impulsivity and manic symptoms. In light of this, psychopathy should be investigated when assessing patients with BD, regardless of the comorbidity of BD with other personality disorders.

Pharmacogenomic Biomarkers and Their Applications in Psychiatry

Realizing the promise of precision medicine in psychiatry is a laudable and beneficial endeavor, since it should markedly reduce morbidity and mortality and, in effect, alleviate the economic and social burden of psychiatric disorders. This review aims to summarize important issues on pharmacogenomics in psychiatry that have laid the foundation towards personalized pharmacotherapy and, in a broader sense, precision medicine. We present major pharmacogenomic biomarkers and their applications in a variety of psychiatric disorders, such as depression, attention-deficit/hyperactivity disorder (ADHD), narcolepsy, schizophrenia, and bipolar disorder. In addition, we extend the scope into epilepsy, since antiepileptic drugs are widely used to treat psychiatric disorders, although epilepsy is conventionally considered to be a neurological disorder.

Hidradenitis Suppurativa and Bipolar Disorders: A Population-Based Study

BACKGROUND

Psychological comorbidities have been reported in patients with hidradenitis suppurativa (HS), yet only a few studies have investigated the possible association between HS and severe psychiatric disorders. The current study aimed to assess the association between HS and bipolar disorder, a major, chronic, psychiatric disease.

METHODS

A nationwide, population-based study was performed utilizing data from the Clalit Health Services (CHS) database in Israel. The study included 4,191 HS patients and 20,941 age- and gender-matched controls. A multivariate binary logistic regression, adjusted for demographic and behavioral risk factors, was performed.

RESULTS

A higher proportion of bipolar disorders was found among HS patients compared to controls (0.7 vs. 0.1%, respectively). There was an increased proportion of active smokers among HS patients than among controls (53.4 vs. 13.5%, respectively). In the multivariate analysis, adjusting for age, sex, and smoking, HS was found to be independently and positively associated with bipolar disorders (OR 2.12, 95% CI 1.21-3.27, p < 0.01), yet after controlling for body mass this association became nonsignificant.

CONCLUSIONS

Bipolar disorders are associated with HS. Future studies should explore whether cardiometabolic deficiencies might account for this association. Healthcare providers should consider this potential co-occurrence as it may impede patient compliance and require appropriate screening and treatment. Results also stress the need for a multidisciplinary approach to optimize management of the disease and its associated comorbidities.

Nitric oxide, asymmetric dimethylarginine, symmetric dimethylarginine and L-arginine levels in psychotic exacerbation of schizophrenia and bipolar disorder manic episode

OBJECTIVES

To examine the changes in nitric oxide (NO), asymmetric dimethylarginine (ADMA), symmetric dimethylarginine (SDMA), and L-arginine levels in schizophrenia during acute psychotic exacerbation and in bipolar disorder during mania and to compare those changes to healthy controls.

METHODS

Thirty schizophrenia patients with acute psychotic exacerbation and 30 bipolar disorder patients with mania, who attended the Psychiatry Department,  Erenköy Hospital for Mental and Nervous Diseases, Istanbul, Turkey, in 2010. Thirty healthy controls were included. The diagnosis was made using the Structured Clinical Interview for Axis I Disorders (SCID-I) interviews. Patients' demographic data were recorded, and NO, SDMA, L-arginine, and ADMA levels were studied.

RESULTS

Nitric oxide levels in schizophrenia patients were significantly lower than the control group. Nitric oxide levels in the bipolar group were lower than the control group but the difference was not statistically significant. The levels of SDMA, ADMA, and L-arginine were found to be significantly higher in schizophrenia and bipolar disorder patients than the control group. The disease duration was slightly negatively correlated with NO levels in bipolar patients. In schizophrenia patients, the disease severity was slightly positively correlated with NO levels.

CONCLUSION

Significant changes in NO, SDMA, ADMA, and L-arginine levels in schizophrenia and bipolar disorder patients suggest that NO and inhibitors of NO might be implicated in the neurobiology of schizophrenia and bipolar disorder.

The role of neurotrophic factors in manic-, anxious- and depressive-like behaviors induced by amphetamine sensitization: Implications to the animal model of bipolar disorder

BACKGROUND

Bipolar disorder (BD) and substance use disorders share common symptoms, such as behavioral sensitization. Amphetamine-induced behavioral sensitization can serve as an animal model of BD. Neurotrophic factors have an important role in BD pathophysiology. This study evaluated the effects of amphetamine sensitization on behavior and neurotrophic factor levels in the brains of rats.

METHODS

Wistar rats received daily intraperitoneal (i.p) injections of dextroamphetamine (d-AMPH) 2 mg/kg or saline for 14 days. After seven days of withdrawal, the animals were challenged with d-AMPH (0.5 mg/kg, i.p) and locomotor behavior was assessed. In a second protocol, rats were similarly treated with d-AMPH (2 mg/kg, i.p) for 14 days. After withdrawal, without d-AMPH challenge, depressive- and anxiety-like behaviors were evaluated through forced swimming test and elevated plus maze. Levels of brain-derived neurotrophic factor (BDNF), nerve growth factor (NGF), neurotrophin 3 (NT-3), neurotrophin 4/5 (NT-4/5) and glial-derived neurotrophic factor (GDNF) were evaluated in the frontal cortex, hippocampus, and striatum.

RESULTS

D-AMPH for 14 days augmented locomotor sensitization to a lower dose of d-AMPH (0.5 mg/kg) after the withdrawal. d-AMPH withdrawal induced depressive- and anxious-like behaviors. BDNF, NGF, and GDNF levels were decreased, while NT-3 and NT-4 levels were increased in brains after d-AMPH sensitization.

LIMITATIONS

Although d-AMPH induces manic-like behavior, the mechanisms underlying these effects can also be related to phenotypes of drug abuse.

CONCLUSIONS

Together, vulnerability to mania-like behavior following d-AMPH challenge and extensive neurotrophic alterations, suggest amphetamine-induced behavioral sensitization is a good model of BD pathophysiology.

A Brain on a Roller Coaster: Can the Dopamine Reward System Act as a Protagonist to Subdue the Ups and Downs of Bipolar Disorder?

One of the most interesting but tenebrous parts of the bipolar disorder (BD) story is the switch between (hypo)mania and depression, which can give bipolar patients a thrilling, but somewhat perilous, ‘ride’. Numerous studies have pointed out that there are some recognizable differences (either state-dependent or state-independent) in several brain regions of people with BD, including components of the brain’s reward system. Understanding the underpinning mechanisms of high and low mood statuses in BD has potential, not only for the development of highly specific and selective pharmaceutical agents, but also for better treatment approaches and psychological interventions to manage BD and, thus, give patients a safer ride. Herein, we review evidence that supports involvement of the reward system in the pathophysiology of mood swings, with the main focus on the mesocorticolimbic dopaminergic neural circuitry. Principally using findings from neuroimaging studies, we aim to signpost readers as to how mood alterations may affect different areas of the reward system and how antipsychotic drugs can influence the activity of these brain areas. Finally, we critically evaluate the hypothesis that the mesocorticolimbic dopamine reward system may act as a functional rheostat for different mood states.

Lithium ameliorates sleep deprivation-induced mania-like behavior, hypothalamic-pituitary-adrenal (HPA) axis alterations, oxidative stress and elevations of cytokine concentrations in the brain and serum of mice

OBJECTIVES

The goal of the present study was to investigate the effects of lithium administration on behavior, oxidative stress parameters and cytokine levels in the periphery and brain of mice subjected to an animal model of mania induced by paradoxical sleep deprivation (PSD).

METHODS

Male C57 mice were treated with saline or lithium for 7 days. The sleep deprivation protocol started on the 5th day during for the last 36 hours of the treatment period. Immediately after the sleep deprivation protocol, animals locomotor activity was evaluated and serum and brain samples was extracted to evaluation of corticosterone and adrenocorticotropic hormone circulating levels, oxidative stress parameters and citokynes levels.

RESULTS

The results showed that PSD induced hyperactivity in mice, which is considered a mania-like behavior. PSD increased lipid peroxidation and oxidative damage to DNA, as well as causing alterations to antioxidant enzymes in the frontal cortex, hippocampus and serum of mice. In addition, PSD increased the levels of cytokines in the brains of mice. Treatment with lithium prevented the mania-like behavior, oxidative damage and cytokine alterations induced by PSD.

CONCLUSIONS

Improving our understanding of oxidative damage in biomolecules, antioxidant mechanisms and the inflammatory system - alterations presented in the animal models of mania - is important in helping us to improve our knowledge concerning the pathophysiology of BD, and the mechanisms of action employed by mood stabilizers.