Journal of psychopharmacology
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J. Psychopharmacol. (Oxford) · Jan 2006
The influence of central administration of dopaminergic and cholinergic agents on morphine-induced amnesia in morphine-sensitized mice.
In the present study, effects of intracerebroventricular (i.c.v.) injections of dopaminergic and cholinergic agents on morphine-induced amnesia in morphine-sensitized mice were investigated by using a one-trial passive avoidance task. Amnesia induced by pre-training morphine was significantly reversed in morphine-sensitized mice, which had previously received once daily injections of morphine (20 and 30 mg/kg, s.c.) for 3 days. Three daily injections of SKF 38393 (1, 2 and 4 g/mouse, i.c.v.) or SCH 23390 (0.25, 0.5, 0.75 and 1 g/mouse, i.c.v.) before morphine, and during morphine-sensitization, decreased and increased the amnesia induced by pre-training morphine respectively. ⋯ Three daily injections of physostigmine (1, 3 and 5 g/mouse, i.c.v.) or atropine (1, 4 and 7 g/mouse, i.c.v.) before morphine, and during morphine-sensitization, decreased and increased the amnesia induced by pre-training morphine respectively. Three daily injections of nicotine (0.75, 1 and 2 g/mouse, i.c.v.) or mecamylamine (1, 3 and 6 g/mouse, i.c.v.) before morphine, also decreased and increased the amnesia induced by pre-training morphine respectively. The results suggest that morphine sensitization affects the impairment of memory formation and thus it is postulated that central dopaminergic and cholinergic systems may play an important role in this effect.
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J. Psychopharmacol. (Oxford) · Nov 2005
ReviewObesity - an epidemic of the twenty-first century: an update for psychiatrists.
Obesity is a chronic relapsing condition associated with significant morbidity and premature mortality. The prevalence of obesity has increased dramatically over the last 20 years and continues to do so, primarily as a result of changes in dietary intake and exercise patterns. There are considerable challenges associated with the management of the obesity epidemic involving both public health policies and individual treatment. ⋯ Appropriate selection of patients and the setting of realistic goals are crucial to the success of any weight-reducing programme. The aim of obesity management is to reduce associated morbidity and mortality, not necessarily to restore normal body weight. While the current trends in obesity are depressing, a better understanding of the pathophysiology and treatment of the condition should allow the clinician to be more optimistic for the future.
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J. Psychopharmacol. (Oxford) · Sep 2005
Clinical TrialPatients in the early phases of schizophrenia and schizoaffective disorders effectively treated with risperidone long-acting injectable.
The efficacy and safety of risperidone long-acting injectable (RLAI) was investigated in patients in the early phases of schizophrenia and schizoaffective disorders (< or = 3 years). Patients who required a treatment change received RLAI (2-weekly gluteal injections of 25, 37.5 or 50 mg, per clinical judgement), without an oral risperidone run-in phase. A total of 382 patients were included in this 6-month open-label study; 73% of patients completed the study. ⋯ The ensured delivery of medication with RLAI resulted in significant symptom improvement in this patient population. Direct initiation of RLAI is well accepted by patients. RLAI might represent a novel option for patients in the early phases of psychosis.
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J. Psychopharmacol. (Oxford) · Sep 2005
Multicenter StudySustained improvement of clinical outcome with risperidone long-acting injectable in psychotic patients previously treated with olanzapine.
The efficacy and tolerability of risperidone long-acting injectable were investigated in patients with schizophrenia or other psychotic disorders who had previously been symptomatically stable on olanzapine treatment. Patients received risperidone long-acting injectable, 25 mg, by intramuscular injection every 2 weeks; the dose could be increased to 37.5 or 50 mg if necessary. Patients were transferred directly from their previous medication to risperidone long-acting injectable without a run-in period of oral risperidone treatment. ⋯ Treatment with risperidone long-acting injectable was well tolerated, and no significant weight gain occurred during the study. This open study suggests that risperidone long-acting injectable produces symptomatic improvement in schizophrenia patients previously considered symptomatically stable with olanzapine, along with improvement in movement disorders. The combination of improved efficacy and good tolerability may have important implications for patient adherence to therapy and subsequent long-term outcomes.
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J. Psychopharmacol. (Oxford) · Jul 2005
Clinical TrialDiazepam suppresses the acquisition but not the expression of 'fear-potentiation' of the acoustic startle response in man.
Sudden auditory stimuli elicit a short-latency muscular response (acoustic startle response) which is enhanced during presentation of a Pavlovian conditioned stimulus (CS) that has previously been paired with an aversive unconditioned stimulus (US) ('fear-potentiation'). In rodents, acute treatment with benzodiazepines blocks both the acquisition of fear-potentiation and the expression of fear-potentiation induced by prior exposure to CS/US pairing. We examined the effect of diazepam on the acquisition and expression of fear-potentiation of the acoustic startle response in man. ⋯ In session 2, the acoustic startle response, the N1/P2 auditory evoked response and the skin conductance response evoked by the sound stimuli were enhanced in the presence of the CS. This fear-potentiation was attenuated in subjects who received diazepam in session 1, but was not affected by the treatment given in session 2. The results indicate that diazepam blocks the acquisition of fear-potentiation of startle responses in man, as in animals, but does not prevent the expression of a previously learned response.