3,318 research outputs found
‘The Greatest Bubble in History’: Stock Prices during the British Railway Mania
No full textAlthough the British Railway Mania has been described as one of the greatest bubbles in history, it has been largely neglected by academics. This paper attempts to redress this neglect by creating a daily stock price index for the 1843-50 period and by assessing the contribution of the many newly-created railways to the bubble-like pattern in stock prices. The paper then examines whether this bubble-like pattern was due to an increase in the stochastic discount factor arising from an increase in the probability of large-scale adoption of railway technology. We find little evidence to support this hypothesis.bubbles, financial crises, Railway Mania
Cannabis use and mania symptoms : a systematic review and meta-analysis
No full textBackground:
Whilst cannabis use appears to be a causal risk factor for the development of schizophrenia-related psychosis, associations with mania remain relatively unknown. This review aimed to examine the impact of cannabis use on the incidence of manic symptoms and on their occurrence in those with pre-existing bipolar disorder.
Methods:
A systematic review of the scientific literature using the PRISMA guidelines. PsychINFO, Cochrane, Scopus, Embase and MEDLINE databases were searched for prospective studies.
Results:
Six articles met inclusion criteria. These sampled 2391 individuals who had experienced mania symptoms. The mean length of follow up was 3.9 years.
Studies support an association between cannabis use and the exacerbation of manic symptoms in those with previously diagnosed bipolar disorder. Furthermore, a meta-analysis of two studies suggests that cannabis use is associated with an approximately 3-fold (Odds Ratio: 2.97; 95% CI: 1.80–4.90) increased risk for the new onset of manic symptoms.
Limitations:
We were only able to identify a small number of studies of variable quality, thus our conclusions remain preliminary.
Conclusions:
Our findings whilst tentative, suggest that cannabis use may worsen the occurrence of manic symptoms in those diagnosed with bipolar disorder, and may also act as a causal risk factor in the incidence of manic symptoms. This underscores the importance of discouraging cannabis use among youth and those with bipolar disorder to help prevent chronic psychiatric morbidity. More high quality prospective studies are required to fully elucidate how cannabis use may contribute to the development of mania over time
Differential treatment of bipolar disorder with old and new antiepileptic drugs
No full textAlthough lithium remains the preferred medication for bipolar disorders, new investigations suggest that only 60 to 80% of patients have a good response with a classical presentation. The antiepileptics carbamazepine and valproate are important alternatives. Several studies have shown that lithium, carbamazepine and valproate are effective in pure mania. Mixed mania and rapid cycling respond, however, well to valproate. One disadvantage of carbamazepine is its enzyme inducing property with the consequence of a decrease of plasma levels of other psychotropic medications and a worsening of psychopathology. First data indicate a good antimanic and antidepressive efficacy of the new antiepileptic drug lamotrigine
Efeitos da agmatina em modelos animais de depressão e mania
No full textDissertação (mestrado) - Universidade Federal de Santa Catarina, Centro de Ciências Biológicas. Programa de Pós-Graduação em Neurociências.Mood disorders are chronic and severe mental disorders. Many compounds, as agmatine, have been investigated regarding their effects and underlying mechanisms in major depression and bipolar disorder. The administration of agmatine, an endogenous cationic amine, elicits an antidepressant-like effect in the mouse forced swimming test (FST) by a mechanism dependent on the inhibition of the NMDA receptors and the L-arginine-nitric oxide (NO) pathway. Since it has been reported that the NO can activate different types of potassium (K+) channels in several tissues, the present study investigated the possibility of synergistic interactions between different types of K+ channel inhibitors and agmatine in the FST. Treatment of mice by i.c.v. route with subeffective doses of tetraethylammonium (a non specific inhibitor of K+ channels, 25 pg/site), glibenclamide (an ATP-sensitive K+ channel inhibitor, 0.5 pg/site), charybdotoxin (a large- and intermediate-conductance calciumactivated K+ channel inhibitor, 25 pg/site) or apamin (a small-conductance calcium-activated K+ channel inhibitor, 10 pg/site), augmented the effect of agmatine (0.001 mg/kg, i.p.) in the FST. Furthermore, the administration of agmatine and the K+ channel inhibitors, alone or in combination, did not affect locomotion in the open-field test. Moreover, the reduction in the immobility time elicited by an active dose of agmatine (10 mg/kg, i.p.) in the FST was prevented by the pretreatment of mice with the K+ channel openers cromakalim (10 ìg/site, i.c.v.) and minoxidil (10 ìg/site, i.c.v.), without affecting locomotion. These results raise the possibility that the antidepressant-like effect of agmatine in the FST is related to its modulatory effects on neuronal excitability, via inhibition of K+ channels. Furthermore, we investigated the effect of agmatine in the ouabain-induced hyperactivity in rats, an animal model of mania. In this study, the pretreatment of the animals with agmatine (0.1, 1 and 10 mg/kg, p.o. administered twice a day for 7 days) was able to attenuate the behavioral and neurochemical changes elicited by acute administration of ouabain, a Na,K-ATPase-inhibiting compound, given by i.c.v. route, in Wistar rats. Ouabain (10 ìM/site) significantly increased motor activity in the open-field test. The pretreatment with lithium chloride (LiCl, 45 mg/kg, p.o.) for seven days completely prevented the hyperactivity, but agmatine (0,1-10 mg/kg) partially prevented the ouabain-induced hyperlocomotion. Ouabain treatment elicited lipid peroxidation (increased TBARS levels) and reduced the glutathione peroxidase (GPx) activity in the hippocampus and glutathione reductase (GR) activity in the cerebral cortex and hippocampus, effects that were completely prevented in rats pretreated with agmatine and LiCl. These results show that agmatine, in a way similar to LiCl, is able to prevent the neurochemical alterations observed in the ouabain-induced model of mania in rats, but was able to reverse only partially the uabain-induced hyperlocomotion. Together, these results suggest that agmatine has not only antidepressant-like effects through an interaction with K+ channels, but also antimanic propierties. Investigar o envolvimeto dos canais de K+ no mecanismo de ação da agmatina no teste do nado forçado e o efeito da agmatina em um modelo animal de mania induzido por ouabaína e sua relação com o estresse oxidativo
Efeitos comportamentais e bioquímicos do ácido ascórbico em modelos de depressão e mania
No full textDissertação (mestrado) - Universidade Federal de Santa Catarina, Centro de Ciências Biológicas, Programa de Pós-Graduação em Bioquímica, Florianópolis, 2015.Os transtornos de humor estão associados a altos índices de morbidade, mortalidade e custo econômico. O ácido ascórbico (AA) é uma vitamina hidrossolúvel cuja propriedade antidepressiva foi reportada em diversos estudos, além disso, essa vitamina tem uma potencial ação antimaníaca pouco explorada. O presente estudo investigou o envolvimento do sistema opióide no efeito tipo-antidepressivo do AA no teste de suspensão pela cauda (TSC), um modelo preditivo muito utilizado na investigação de novos compostos com ação antidepressiva. Além disso, esse estudo investigou também o possível efeito antimaníaco do AA em um modelo de mania induzido por m-anfetamina (m-AMPH). O tratamento de camundongos Swiss com um antagonista não seletivo de receptores opióides, naloxona, foi capaz de prevenir a diminuição no tempo de imobilidade causada pela administração de uma dose ativa de AA (1 mg/kg) no TSC. Adicionalmente, a administração de um antagonista específico de receptores opióides do tipo µ1, naloxonazina, também preveniu a ação tipo-antidepressiva da mesma dose de AA no TSC, sem causar alteração locomotora no teste do campo aberto (TCA). A administração de naloxonazina e AA não causou alteração significativa no imunoconteúdo de PSD95 em homogenatos de hipocampo e córtex pré-frontal dos animais. Em outro conjunto de experimentos, ratos Wistar foram tratados, duas vezes ao dia por 14 dias, com cloreto de lítio (LiCl, 45 mg/kg, p.o.), AA (0,1; 1; 10 e 100 mg/kg, p.o.) ou veículo (água destilada, 1ml/kg). A partir do 8º dia foi administrada uma injeção diária de m-AMPH (2 mg/kg, i.p.) ou veículo (salina, 1ml/kg). No 15º dia foi administrada uma dose única de m-AMPH e os animais foram testados no TCA após 2 horas. A m-AMPH aumentou a atividade locomotora e exploratória dos animais no campo aberto, e esse comportamento foi prevenido pelo tratamento com LiCl, mas não com AA. A análise do imunoconteúdo de BDNF no hipocampo dos animais mostrou um efeito principal da m-AMPH, a qual diminuiu o imunoconteúdo dessa proteína. No córtex pré-frontal, o grupo tratado com m-AMPH teve um aumento no imunoconteúdo de BDNF, que foi prevenido pelo tratamento com AA na dose de 10 mg/kg. O imunoconteúdo de FGF-2 não sofreu alteração significativa no hipocampo em nenhum dos grupos, mas houve um efeito principal da m-AMPH aumentando os níveis dessa neurotrofina no córtex pré-frontal. Nossos resultados mostram, primeiramente, que o efeito tipo-antidepressivo do AA no TSC parece ser dependente da ativação do sistema opióide, especialmente dos receptores do tipo µ1, e que, a ativação da via mTOR-PSD95, apesar de estar envolvida no mecanismo tipo-antidepressivo do AA nesse teste, aparentemente não está relacionada à ativação do sistema opióide pelo AA. Adicionalmente, nossos resultados mostram que o AA não tem efeito no modelo animal de mania induzido por m-AMPH, e que a desregulação de BDNF e FGF-2 parece estar envolvida na manifestação de mania produzida por este modelo. Conjuntamente, nossos resultados podem ajudar no esclarecimento do papel do AA na regulação do humor.Abstract : Mood disorders are associated with high levels of morbidity, mortality and a high economic cost. Ascorbic acid (AA) is a water-soluble vitamin whose antidepressant properties have been reported in several studies. Besides, this vitamin has a potential antimanic action that has not been explored yet. The present study investigated the involvement of the opioid system in the antidepressant-like effect of AA in the tail suspension test (TST), a predictive model widely used for the investigation of new antidepressant compounds. Furthermore, this study also investigated the possible antimanic effect of AA in an animal model of mania induced by m-amphetamine (m-AMPH). The treatment of Swiss mice with a non-selective opioid receptor inhibitor, naloxone, was able to prevent the reduced immobility time caused by an active dose of AA (1 mg/kg) in the TST. Additionally, the administration of a selective µ1-opioid receptor antagonist, naloxonazine, also prevented de antidepressant-like action of the same dose of AA in the TST, without causing any locomotor alteration in the open field test (OFT). The administration of naloxonazine and AA did not cause any alteration in the immunocontent of PSD95 in hippocampus and prefrontal cortex homogenates. In another set of experiments, Wistar rats were treated, twice a day for 14 days, with lithium chloride (LiCl, 45 mg.kg, p.o.), AA (0.1; 1; 10 and 100 mg/kg, p.o.) or vehicle (distilled water, 1ml/kg). From the 8th to the 14th day, an injection of m-amphetamine (m-AMPH, 2 mg/kg, i.p.) or vehicle (saline, 1ml/kg) was administered. In the 15th day, a single administration of m-AMPH was given and the animals were subjected to the OFT after two hours. m-AMPH treatment increased locomotor and exploratory activity, and these behavioral alterations were prevented by the treatment with LiCl, but not AA. Regarding hippocampal BDNF immunocontent, we observed a main effect of m-AMPH treatment, which decreased the immunocontent of this protein. In the prefrontal cortex, the group treated with m-AMPH displayed an increased BDNF immunocontent, which was partially prevented by the treatment with LiCl and totally prevented by AA at 10 mg/kg. The immunocontent of FGF-2 was not altered in the hippocampus in any of the groups, but there was a main effect of m-AMPH increasing the level of this neurotrophin in the prefrontal cortex. Our results show, primarily, that the AA antidepressant-like effect in the TST seems to be dependent on the activation of the opioid system, especially µ1-opioid receptor, and that, although mTOR-PSD95 pathway activation is implicated in the antidepressant-like effect of AA in the TST, apparently it is not related to the activation of the opioid system by AA. Additionally, our results show that AA has no effect in the animal model of mania induced by m-AMPH, and that a BDNF and FGF-2 dysregulation seems to be involved in the mania manifestation caused by this model. Altogether, our results may help to understand the role of AA in mood regulation
Treatment and prevention of mania in bipolar I disorder: focus on aripiprazole
No full textDavid J MuzinaCenter for Mood Disorders Treatment and Research, Cleveland Clinic Neurological Institute, Cleveland, Ohio, USAAbstract: Aripiprazole is a second-generation antipsychotic with a unique pharmacologic receptor profile that has efficacy in the treatment and prevention of mania in bipolar I disorder. This article reviews the evidence supporting treatment of adults with bipolar I disorder using aripiprazole as monotherapy or adjunctively during acute mania and its utility as an intramuscular agent for agitation in manic patients. Results from one of the longest bipolar maintenance trials which support aripiprazole as a prophylactic mood stabilizer, specifically against manic relapses, will be discussed as well as a post-hoc analysis that suggests efficacy for rapid cycling bipolar disorder. Safety and tolerability issues, patient-focused perspectives and aripiprazole’s place in therapy for bipolar mania will be covered.Keywords: bipolar disorder, mania, prevention, aripiprazole, rapid cyclin
L’ apertura sul futuro della Teoria del restauro. : La lezione di Brandi letta da Giovanni Urbani
No full textL’ apertura sul futuro della Teoria del restauro. : La lezione di Brandi letta da Giovanni Urbani
No full text“Due strumenti per la valutazione dell’attaccamento romantico a confronto: Ecr ed Ecr-r”
No full textpeer reviewedL’obiettivo della ricerca era di mettere a confronto due strumenti ampiamente usati per la valutazione dell’attaccamento romantico, somministrandoli entrambi ad uno stesso gruppo di soggetti adulti.
Il primo era il questionario Experiences in Close Relationships (ECR, Brennan, Clark & Shaker, 1998), uno degli strumenti più utilizzati e validati, anche in ambito italiano (Picardi et al., 2000, 2002; Agostoni & Manzoni, 2007).
Il secondo strumento era la versione rivista dell’ECR, denominata Experiences in Close Relationships-Revised (ECR-R), sviluppata da Fraley, Waller e Brennan (2000) e che, secondo gli autori, ha permesso di migliorare la precisione di misurazione dello strumento di partenza.
Alla ricerca hanno preso parte 180 soggetti adulti (età media 22,43 anni, ds = 2,56), ripartiti in tre sottogruppi, relativi allo status relazionale (single, fidanzati da meno di due anni e fidanzati da più di due anni) di uguale numerosità; metà erano femmine e metà maschi.
La procedura ha comportato la somministrazione a tutti i soggetti della versione italiana dell’ECR (Picardi et al., 2000) e dell’ECR-R (nella nostra versione: Calvo, 2008) controbilanciando l’ordine di presentazione degli strumenti all’interno dei sottogruppi.
In sintesi, i risultati hanno evidenziato come entrambi gli strumenti abbiano un’elevata consistenza interna, del tutto simile fra loro (Alfa di Cronbach: ECR evitamento = 0,93; ECR ansietà = 0,88; ECR-R evitamento = 0,92; ECR-R ansietà = 0,88) e un’alta correlazione fra le scale corrispondenti (Evitamento ECR e ECR-R, r = .92, Ansietà ECR e ECR-R, , r = .82). L’ECR presenta una maggiore indipendenza fra le due scale di evitamento e ansità (r = .18) rispetto all’ECR-R (r = .40).
Per quanto concerne la distribuzione dei punteggi, non vi sono differenze significative fra i due strumenti nella media dell’evitamento (t[179]=-1.65, ns) mentre vi è una differenza significativa rispetto all’ansietà (t[179]=10.1, p = .001). In altre parole, uno stesso soggetto tenderà ad avere punteggi di ansietà più elevati se valuto con l’ECR rispetto all’ECR-R (da qui l’evidenza che non è possibile utilizzare in modo intercambiabile le distribuzioni normative dei due strumenti)
La fase terminale della malattia oncologica: uno studio nell'ottica della teoria dell'attaccamento
No full textpeer reviewedLa presente ricerca aveva lo scopo di studiare le influenze dello stile di attaccamento adulto sulla qualità del supporto emotivo fra il paziente oncologico e il suo caregiver di riferimento e sull’alleanza di lavoro con i medici di reparto, durante il ricovero in una struttura hospice, specializzata nella gestione della fase terminale della malattia.
Poiché lo stile di attaccamento adulto sembra giocare un ruolo importante nella gestione dello stress psicologico percepito dall’individuo nelle circostanze stressanti e nella capacità di fare affidamento sugli altri (Florian & Mikulincer, 1998), abbiamo ipotizzato che anche nella condizione di disagio estremo della fase terminale di una malattia, l’attaccamento sicuro potesse aiutare il soggetto ad affrontare le difficoltà del momento e che, invece, un attaccamento insicuro tendesse ad aumentare la vulnerabilità e l’angoscia (Mikulincer & Orbach, 1995).
Lo studio si è proposto di verificare l’ipotesi secondo cui lo stile di attaccamento tenda a influenzare due aspetti importanti della fase terminale della malattia: la qualità del supporto emotivo dato dalla relazione con il caregiver e la qualità dell’alleanza di lavoro con il medico curante. Ci aspettavamo che i malati con attaccamento sicuro tendessero a percepire più positivamente la qualità del supporto emotivo con il caregiver e, analogamente, a valutare più favorevolmente l’alleanza di lavoro con il medico, rispetto ai pazienti insicuri
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