Cannabidiol blocks long-lasting behavioral consequences of predator threat stress: Possible involvement of 5HT1A receptors

Posttraumatic stress disorder (PTSD) is an incapacitating syndrome that follows a traumatic experience. Predator exposure promotes long-lasting anxiogenic effect in rodents, an effect related to symptoms found in PTSD patients. Cannabidiol (CBD) is a non-psychotomimetic component of Cannabis sativa with anxiolytic effects. The present study investigated the anti-anxiety actions of CBD administration in a model of PTSD. Male Wistar rats exposed to a predator (cat) received, 1 h later, singled or repeated i.p. administration of vehicle or CBD. Seven days after the stress animals were submitted to the elevated plus maze. To investigate the involvement of 5HT1A receptors in CBD effects animals were pre-treated with WAY100635, a 5HT1A receptor antagonist. To explore possible neurobiological mechanisms involved in these effects, 5HT1A receptor mRNA and BDNF protein expression were measured in the hippocampus, frontal cortex, amygdaloid complex and dorsal periaqueductal gray. Repeated administration of CBD prevented long-lasting anxiogenic effects promoted by a single predator exposure. Pretreatment with WAY100635 attenuated CBD effects. Seven days after predator exposure 5HT1A mRNA expression was up regulated in the frontal cortex and hippocampus. CBD and paroxetine failed to prevent this effect. No change in BDNF expression was found. In conclusion, predator exposure promotes long-lasting up-regulation of 5HT1A receptor gene expression in the hippocampus and frontal cortex. Repeated CBD administration prevents the long-lasting anxiogenic effects observed after predator exposure probably by facilitating 5HT1A receptors neurotransmission. Our results suggest that CBD has beneficial potential for PTSD treatment and that 5HT1A receptors could be a therapeutic target in this disorder. (C) 2012 Elsevier Ltd. All rights reserved.

Traumatic memories: bridging the gap between functional neuroimaging and psychotherapy

Objective: Neuroimaging studies have highlighted important issues related to structural and functional brain changes found in sufferers of psychological trauma that may influence their ability to synthesize, categorize, and integrate traumatic memories. Methods: Literature review and critical analysis and synthesis. Results: Traumatic memories are diagnostic symptoms of post-traumatic stress disorder (PTSD), and the dual representation theory posits separate memory systems subserving vivid re-experiencing (non-hippocampally dependent) versus declarative autobiographical memories of trauma (hippocampally dependent). But the psychopathological signs of trauma are not static over time, nor is the expression of traumatic memories. Multiple memory systems are activated simultaneously and in parallel on various occasions. Neural circuitry interaction is a crucial aspect in the development of a psychotherapeutic approach that may favour an integrative translation of the sensory fragments of the traumatic memory into a declarative memory system. Conclusion: The relationship between neuroimaging findings and psychological approaches is discussed for greater efficacy in the treatment of psychologically traumatized patients.

The Dorsolateral Periaqueductal Gray and Its Role in Mediating Fear Learning to Life Threatening Events

The dorsolateral column of the periaqueductal gray (dlPAG) integrates aversive emotional experiences and represents an important site responding to life threatening situations, such as hypoxia, cardiac pain and predator threats. Previous studies have shown that the dorsal PAG also supports fear learning; and we have currently explored how the dlPAG influences associative learning. We have first shown that N-methyl-D-aspartate (NMDA) 100 pmol injection in the dlPAG works as a valuable unconditioned stimulus (US) for the acquisition of olfactory fear conditioning (OFC) using amyl acetate odor as conditioned stimulus (CS). Next, we revisited the ascending projections of the dlPAG to the thalamus and hypothalamus to reveal potential paths that could mediate associative learning during OFC. Accordingly, the most important ascending target of the dlPAG is the hypothalamic defensive circuit, and we were able to show that pharmacological inactivation using beta-adrenoceptor blockade of the dorsal premammillary nucleus, the main exit way for the hypothalamic defensive circuit to thalamo-cortical circuits involved in fear learning, impaired the acquisition of the OFC promoted by NMDA stimulation of the dlPAG. Moreover, our tracing study revealed multiple parallel paths from the dlPAG to several thalamic targets linked to cortical-hippocampal-amygdalar circuits involved in fear learning. Overall, the results point to a major role of the dlPAG in the mediation of aversive associative learning via ascending projections to the medial hypothalamic defensive circuit, and perhaps, to other thalamic targets, as well. These results provide interesting perspectives to understand how life threatening events impact on fear learning, and should be useful to understand pathological fear memory encoding in anxiety disorders.

On Disruption of Fear Memory by Reconsolidation Blockade: Evidence from Cannabidiol Treatment

The search for reconsolidation blockers may uncover clinically relevant drugs for disrupting memories of significant stressful life experiences, such as those underlying the posttraumatic stress disorder. Considering the safety of systemically administered cannabidiol (CBD), the major non-psychotomimetic component of Cannabis sativa, to animals and humans, the present study sought to investigate whether and how this phytocannabinoid (3-30 mg/kg intraperitoneally; i.p.) could mitigate an established memory, by blockade of its reconsolidation, evaluated in a contextual fear-conditioning paradigm in rats. We report that CBD is able to disrupt 1- and 7-days-old memories when administered immediately, but not 6 h, after their retrieval for 3 min, with the dose of 10 mg/kg being the most effective. This effect persists in either case for at least 1 week, but is prevented when memory reactivation was omitted, or when the cannabinoid type-1 receptors were antagonized selectively with AM251 (1.0 mg/kg). Pretreatment with the serotonin type-1A receptor antagonist WAY100635, however, failed to block CBD effects. These results highlight that recent and older fear memories are equally vulnerable to disruption induced by CBD through reconsolidation blockade, with a consequent long-lasting relief in contextual fear-induced freezing. Importantly, this CBD effect is dependent on memory reactivation, restricted to time window of <6h, and is possibly dependent on cannabinoid type-1 receptor-mediated signaling mechanisms. We also observed that the fear memories disrupted by CBD treatment do not show reinstatement or spontaneous recovery over 22 days. These findings support the view that reconsolidation blockade, rather than facilitated extinction, accounts for the aforementioned CBD results in our experimental conditions. Neuropsychopharmacology (2012) 37, 2132-2142; doi:10.1038/npp.2012.63; published online 2 May 2012

Clinical features of obsessive-compulsive disorder with hoarding symptoms: A multicenter study

Background: Factor analyses indicate that hoarding symptoms constitute a distinctive dimension of obsessive-compulsive disorder (OCD), usually associated with higher severity and limited insight. The aim was to compare demographic and clinical features of OCD patients with and without hoarding symptoms. Method: A cross sectional study was conducted with 1001 DSM-IV OCD patients from the Brazilian Research Consortium of Obsessive-Compulsive Spectrum Disorders (CTOC), using several instruments. The presence and severity of hoarding symptoms were determined using the Dimensional Yale-Brown Obsessive-Compulsive Scale. Statistical univariate analyses comparing factors possibly associated with hoarding symptoms were conducted, followed by logistic regression to adjust the results for possible confounders. Results: Approximately half of the sample (52.7%, n = 528) presented hoarding symptoms, but only four patients presented solely the hoarding dimension. Hoarding was the least severe dimension in the total sample (mean score: 3.89). The most common lifetime hoarding symptom was the obsessive thought of needing to collect and keep things for the future (44.0%, n = 440). After logistic regression, the following variables remained independently associated with hoarding symptoms: being older, living alone, earlier age of symptoms onset, insidious onset of obsessions, higher anxiety scores, poorer insight and higher frequency of the symmetry-ordering symptom dimension. Concerning comorbidities, major depressive, posttraumatic stress and attention deficit/hyperactivity disorders, compulsive buying and tic disorders remained associated with the hoarding dimension. Conclusion: OCD hoarding patients are more likely to present certain clinical features, but further studies are needed to determine whether OCD patients with hoarding symptoms constitute an etiologically discrete subgroup. (C) 2012 Elsevier Ltd. All rights reserved.

Late-onset social anxiety disorder following traumatic brain injury

Background: Neuropsychiatric sequelae are the predominant long-term disability after traumatic brain injury (TBI). This study reports a case of late-onset social anxiety disorder (SAD) following TBI. Case report: A patient that was spontaneous and extroverted up to 18-years-old started to exhibit significant social anxiety symptoms. These symptoms became progressively worse and he sought treatment at age 21. He had a previous history of traumatic brain injury (TBI) at age 17. Neuroimaging investigations (CT, SPECT and MRI) showed a bony protuberance on the left frontal bone, with mass effect on the left frontal lobe. He had no neurological signs or symptoms. The patient underwent neurosurgery with gross total resection of the lesion and the pathological examination was compatible with intradiploic haematoma. Conclusions: Psychiatric symptoms may be the only findings in the initial manifestation of slowly growing extra-axial space-occupying lesions that compress the frontal lobe from the outside. Focal neurological symptoms may occur only when the lesion becomes large. This case report underscores the need for careful exclusion of general medical conditions and TBI history in cases of late-onset SAD and may also contribute to the elucidation of the neurobiology of this disorder.

Does anti-obsessional pharmacotherapy treat so-called comorbid depressive and anxiety states?

Background: Obsessive-compulsive disorder (OCD) is a chronic condition that normally presents high rates of psychiatric comorbidity. Depression, tic disorders and other anxiety disorders are among the most common comorbidities in OCD adult patients. There is evidence that the higher the number of psychiatric comorbidities, the worse the OCD treatment response. However, little is known about the impact of OCD treatment on the outcome of the psychiatric comorbidities usually present in OCD patients. The aim of this study was to investigate the impact of exclusive, conventional treatments for OCD on the outcome of additional psychiatric disorders of OCD patients, detected at baseline. Methods: Seventy-six patients with primary OCD admitted to the treatment protocols of the Obsessive-Compulsive Spectrum Disorders Program between July 2007 and December 2009 were evaluated at pre-treatment and after 12 months. Data were analyzed to verify possible associations between,OCD treatment response and the outcome of psychiatric comorbidities. Results: Results showed a significant association between OCD treatment response and improvement of major depression and dysthymia (p-value = 0.002), other anxiety disorders (generalized anxiety disorder, social phobia, specific phobia, posttraumatic stress disorder, panic disorder, agoraphobia and anxiety disorder not otherwise specified) (p-value = 0.054) and tic disorders (p-value = 0.043). Limitations: This is an open, non-blinded study, without rating scales for comorbid conditions. Further research is necessary focusing on the possible mechanisms by which OCD treatment could improve these specific disorders. Conclusions: Our results suggest that certain comorbid disorders may benefit from OCD-targeted treatment. (C) 2012 Elsevier B.V. All rights reserved.

Should Psychotherapy Consider Reincarnation?

There is increasing recognition of the need to take into account the cultural environment and belief systems of psychotherapy patients because these values reflect basic assumptions about man's nature and the cognitive references used to cope with psychological difficulties. Currently accepted psychotherapeutic approaches take no account of the belief in life after death held by most of the world's population. The World Values Survey (http://www.worldvaluessurvey.org) showed that there are large numbers of reincarnationists around the world, and whatever the reasons for believing in reincarnation, psychotherapeutic approaches should not ignore this significant group of people. Respect for patient opinions and subjective realities is a therapeutic need and an ethical duty, even though therapists may not share the same beliefs. Guidelines are suggested for professionals to develop collaborative models that help patients mobilize their intrinsic intelligence to find solutions to their complaints.