Prevalence of pain flashbacks in posttraumatic stress disorder arising from exposure to multiple traumas or childhood traumatization.

BACKGROUND: Flashbacks are a form of multisensory memory that are experienced with a "happening in the present" quality. Pain flashbacks are a re-experiencing of pain felt at the time of a traumatic event. It is unclear how common pain flashbacks are. AIMS: The current study was designed primarily to assess the prevalence of pain flashbacks in a sample of patients with posttraumatic stress disorder (PTSD). METHODS: We assessed the prevalence of pain flashbacks over a period of 2 years in patients (n = 166) referred to a psychological trauma service in the UK. Patients underwent a clinical screen for PTSD and completed a self-report measure of pain flashbacks. RESULTS: Pain flashbacks were classified as present in 49% of a sample of complex trauma patients meeting criteria for PTSD. Pain flashbacks were positively associated with the extent of pain at the time of trauma. CONCLUSIONS: Pain re-experiencing in PTSD, and its relative absence in nonclinical populations, supports an account of memory in which perceptual details can be re-experienced when memories have been encoded under conditions of extreme stress. It may be possible to conceptualize some cases of unexplained pain as pain flashbacks or of having a trauma origin.

Contexte: Les flashbacks sont une forme de souvenir multisensoriel qui se manifeste en donnant l'impression de se dérouler dans le présent. Les flashbacks douleureux sont une reviviscence de la douleur ressentie au moment d'un évènement traumatique. On ne sait pas à quel point les flashbacks douleureux sont communs.But: La présente étude a été conçue principalement pour évaluer la prévalence des flashbacks douleureux au sein d'un échantillons de patients souffrant d'un trouble de stress post-traumatique (TSPT).Méthodes: Nous avons évalué la prévalence des flashbacks douleureux sur une période de deux ans chez des patients (n = 166) référés à un service spécialisé dans les traumstismes psychologiques en Grande-Bretagne. Les patients ont été soumis à un dépistage du TSPT et ont répondu à un questionnaire portant sur les flashbacks douleureux.Résultats: Les flashbacks douleureux étaient présents chez 49 % des participants d'un échantillon complexe de patients souffrant de traumatismes qui répondaient aux critères pour le TSPT. Une association positive a été observée entre les flashbacks douleureux et le degré de douleur ressenti au moment du traumatisme.Conclusions: La reviviscence de la douleur dans les cas de TSPT et son absence relative au sein de populations non cliniques semblent démontrer que les détails perceptuels d'un souvenir peuvent être revécus lorsqu'ils ont été encodés dans des conditions de stress extrême. Certains cas de douleur inexpliquée peuvent être considérés comme des flashbacks douleureux, ou comme ayant une origine traumatique.

LSD enhances suggestibility in healthy volunteers.

RATIONALE: Lysergic acid diethylamide (LSD) has a history of use as a psychotherapeutic aid in the treatment of mood disorders and addiction, and it was also explored as an enhancer of mind control. OBJECTIVES: The present study sought to test the effect of LSD on suggestibility in a modern research study. METHODS: Ten healthy volunteers were administered with intravenous (i.v.) LSD (40-80 µg) in a within-subject placebo-controlled design. Suggestibility and cued mental imagery were assessed using the Creative Imagination Scale (CIS) and a mental imagery test (MIT). CIS and MIT items were split into two versions (A and B), balanced for 'efficacy' (i.e. A ≈ B) and counterbalanced across conditions (i.e. 50 % completed version 'A' under LSD). The MIT and CIS were issued 110 and 140 min, respectively, post-infusion, corresponding with the peak drug effects. RESULTS: Volunteers gave significantly higher ratings for the CIS (p = 0.018), but not the MIT (p = 0.11), after LSD than placebo. The magnitude of suggestibility enhancement under LSD was positively correlated with trait conscientiousness measured at baseline (p = 0.0005). CONCLUSIONS: These results imply that the influence of suggestion is enhanced by LSD. Enhanced suggestibility under LSD may have implications for its use as an adjunct to psychotherapy, where suggestibility plays a major role. That cued imagery was unaffected by LSD implies that suggestions must be of a sufficient duration and level of detail to be enhanced by the drug. The results also imply that individuals with high trait conscientiousness are especially sensitive to the suggestibility-enhancing effects of LSD.

Association between flashbacks and structural brain abnormalities in posttraumatic stress disorder.

OBJECTIVE: Posttraumatic stress disorder (PTSD) is reliably associated with reduced brain volume relative to healthy controls, in areas similar to those found in depression. We investigated whether in a PTSD sample brain volumes in these areas were related to reporting specific symptoms of PTSD or to overall symptom severity. METHOD: Structural MRI scans were obtained from 28 participants diagnosed with PTSD according to DSM-IV-TR. Participants reported the extent of individual PTSD symptoms using the Posttraumatic Diagnostic Scale. Voxel-based morphometry applying the Dartel algorithm implemented within SPM5 was used to identify volumetric changes, related to PTSD total, symptom cluster, and individual symptom scores. RESULTS: Brain volume was unrelated to overall PTSD severity, but greater reexperiencing scores predicted reduced volumes in the middle temporal and inferior occipital cortices. Increased reports of flashbacks predicted reduced volume in the insula/parietal operculum and in the inferior temporal gyrus. CONCLUSION: The data illustrate the value of analyses at the symptom level within a patient population to supplement group comparisons of patients and healthy controls. Areas identified were consistent with a neurobiological account of flashbacks implicating specific abnormalities in the ventral visual stream.

Enhancement of suggestibility and imaginative ability with nitrous oxide.

RATIONALE: Imaginative suggestibility, a trait closely related to hypnotic suggestibility, is modifiable under some circumstances. Nitrous oxide (laughing gas) is commonly used for sedation in dentistry and is reported to be more effective when combined with appropriate suggestions. OBJECTIVE: The aim of this study was to determine whether nitrous oxide inhalation alters imaginative suggestibility and imagery vividness. METHODS: Thirty participants were tested twice in a within-subjects design, once during inhalation of 25% nitrous oxide and once during inhalation of air plus oxygen. Before the study, participants' expectancies regarding the effects of nitrous oxide were assessed. Participants were blinded to drug administration. During each session, participants were verbally administered detailed measures of imagination and suggestibility: the Sheehan-Betts Quality of Mental Imagery scale and the Stanford Hypnotic Susceptibility Scale Form C, minus the hypnotic induction. RESULTS: Imaginative suggestibility and imaginative ability (imagery vividness) were both elevated in the nitrous oxide condition. This effect was unrelated to participants' expectations regarding the effects of the drug. CONCLUSIONS: Nitrous oxide increased imaginative suggestibility and imaginative ability. Possible explanations of these findings are discussed with respect to the effects of N-methyl-d-aspartate antagonists and to other pharmacological effects upon suggestibility and imagination.

Pain flashbacks following the July 7th 2005 London bombings.

Flashbacks in posttraumatic stress disorder (PTSD) are commonly experienced as visual, auditory, olfactory or tactile re-livings of a previously experienced traumatic event. We present the case report of one survivor of the July 7th 2005 London underground bombings who was diagnosed with PTSD and who experienced painful flashbacks. We present retrospective multidimensional measures of his pain using standardised instruments. The case provides further evidence that somatosensory re-experiencing of pain memories is possible. Findings are discussed with regards to memory for pain.