Neuropsychopharmacology : official publication of the American College of Neuropsychopharmacology
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Neuropsychopharmacology · Nov 2005
Comparative StudyMotivational effects of cannabinoids and opioids on food reinforcement depend on simultaneous activation of cannabinoid and opioid systems.
Strong functional interactions exist between endogenous cannabinoid and opioid systems. Here, we investigated whether cannabinoid-opioid interactions modulate motivational effects of food reinforcement. In rats responding for food under a progressive-ratio schedule, the maximal effort (break point) expended to obtain 45 mg pellets depended on the level of food deprivation, with free-feeding reducing break points and food-deprivation increasing break points. ⋯ Furthermore, THC's effects were blocked by naloxone and morphine's effects were blocked by rimonabant, demonstrating that mu-opioid receptors were involved in the effects of THC and cannabinoid CB1 receptors were involved in the effects of morphine on food-reinforced behavior. Thus, activation of both endogenous cannabinoid and opioid systems appears to jointly facilitate motivational effects of food measured under progressive-ratio schedules of reinforcement and this facilitatory modulation appears to critically depend on interactions between these two systems. These findings support the proposed therapeutic utility of cannabinoid agonists and antagonists in eating disorders.
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Neuropsychopharmacology · Oct 2005
Clinical TrialPsychopathology in the offspring of parents with bipolar disorder: a controlled study.
To examine the risk for psychopathology in offspring at risk for bipolar disorder and the course of psychiatric disorders in these youth. ⋯ These findings support the hypothesis that offspring of parents with bipolar disorder are at significantly increased risk for developing a wide range of severe psychiatric disorders and accompanying dysfunction. Early disruptive behavior and anxiety disorders, as well as early-onset depression, may be useful markers of risk for subsequent bipolar disorder in high-risk samples.
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Neuropsychopharmacology · Sep 2005
Comparative StudyRegional gray matter abnormalities in obsessive-compulsive disorder: a voxel-based morphometry study.
Several structural magnetic resonance imaging (MRI) studies have investigated the presence of brain abnormalities in obsessive-compulsive disorder (OCD) but have not produced consistent findings. This might be partly related to their use of a regions-of-interest approach. We assessed gray matter volumes in 19 OCD subjects and 15 healthy volunteers, using voxel-based morphometry (VBM). ⋯ Our findings are consistent with previous studies implicating dysfunction of orbitofrontal, cingulate, thalamic, and temporolimbic regions in OCD and suggest that the involvement of the parietal cortex in the pathophysiology of OCD warrants further investigation.
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Neuropsychopharmacology · Aug 2005
Randomized Controlled Trial Comparative Study Clinical TrialProbing for affective side effects of drugs used in geriatric practice: use of daily diaries to test for effects of metoclopramide and naproxen.
The aim of this study was to develop the use of daily diaries of affects and events as measures of pharmacological effects on affective processes and to apply them to evaluate the possible affective toxicity of metoclopramide and naproxen, two medications commonly used in geriatric practice. In all, 105 adults aged 65 years or older were randomized to receive metoclopramide (up to 40 mg/day), naproxen (up to 1000 mg/day), or placebo under double-blind conditions for a period of 5 weeks. Patients were seen weekly for evaluations of affective and cognitive outcomes as well as safety. ⋯ The findings confirm the utility of diary methods for studying drug effects on affective processes in normal elderly subjects. They suggest that both metoclopramide and naproxen can affect the associations between daily events and affects. If replicated, they would demonstrate that drug effects can extend beyond the intensity of affect and/or the emergence of full-fledged psychiatric disorders to include moderation of the interactions between daily events and affect.
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Neuropsychopharmacology · Jun 2005
Clinical TrialHypothalamic-pituitary-adrenal axis activity and sleep in posttraumatic stress disorder.
Alterations of the hypothalamic-pituitary-adrenal (HPA) axis and sleep disturbances have been described separately in post-traumatic stress disorder (PTSD). It is not known if HPA alterations and sleep disturbances are associated in PTSD. This study examined sleep and HPA activity in 20 male medication-free subjects with PTSD and 16 matched healthy controls. ⋯ Our results suggest that increased cortisol is negatively associated with delta sleep. This may contribute to sleep abnormalities in conditions associated with elevated cortisol, possibly including PTSD. Future studies should explore the temporal relationship between HPA activity, sleep disturbances, and psychopathology after a traumatic event.