Towards virtual reality exposure therapy for cocaine use disorder: A feasibility study of inducing cocaine craving through virtual reality.

Background: Craving is a core symptom of cocaine use disorders (CUD). Inducing craving in exposure to substance cues is of relevant interest for numerous clinical applications. Virtual reality exposure (VRE) might be a promising candidate for improving cue-exposure paradigms but remains almost not studied for cocaine. This feasibility study's main aim is to assess whether VRE to cocaine cues is capable to induce cocaine craving compared with VRE to neutral cues. Methods: We conducted a within-subjects controlled trial in which cocaine users performed 3 consecutive 10 mins-tasks: VRE to neutral and cocaine cues, and a relaxation-based resting procedure. The primary outcome was the change in Cocaine Craving Questionnaire-Brief (CCQ-Brief) scores between VRE to neutral and cocaine cues. Secondary outcomes included between-tasks changes in scores of cocaine craving, pleasant/unpleasant emotions as well as self-efficacy to cope with craving. Results: We recruited 11 chronic cocaine users including mostly crack smokers (45 %), cocaine snorters (36 %) and injectors (18 %), with 73 % of participants meeting DSM-IV criteria for cocaine dependence and/or abuse. Non-parametrical sign tests indicated significant large increases of CCQ-Brief scores from neutral to cocaine cue-VRE (S(11) = 11, p < 0.01, Cliff's Δ = 0.65, 95 % CI: 0.17-0.88). Exploratory comparative analyses indicated significant changes after our post-cues VRE relaxation procedure, with cocaine craving and emotions restored to baseline. Conclusions: VRE to cocaine cues was feasible and capable to induce cocaine craving in cocaine users. This second VRE-based cue-reactivity study in cocaine paves the way for unexplored research on VRE clinical applications for CUD.

NREM sleep EEG slow waves in autistic and typically developing children: Morphological characteristics and scalp distribution.

Autism is a developmental disorder with a neurobiological aetiology. Studies of the autistic brain identified atypical developmental trajectories that may lead to an impaired capacity to modulate electroencephalogram activity during sleep. We assessed the topography and characteristics of non-rapid eye movement sleep electroencephalogram slow waves in 26 boys aged between 6 and 13 years old: 13 with an autism spectrum disorder and 13 typically developing. None of the participants was medicated, intellectually disabled, reported poor sleep, or suffered from medical co-morbidities. Results are derived from a second consecutive night of polysomnography in a sleep laboratory. Slow waves (0.3-4.0 Hz; >75 µV) were automatically detected on artefact-free sections of non-rapid eye movement sleep along the anteroposterior axis in frontal, central, parietal and occipital derivations. Slow wave density (number per minute), amplitude (µV), slope (µV s-1 ) and duration (s) were computed for the first four non-rapid eye movement periods. Slow wave characteristics comparisons between groups, derivations and non-rapid eye movement periods were assessed with three-way mixed ANOVAs. Slow wave density, amplitude, slope and duration were higher in anterior compared with most posterior derivations in both groups. Children with autism spectrum disorder showed lower differences in slow waves between recording sites along the anteroposterior axis than typically developing children. These group differences in the topography of slow wave characteristics were stable across the night. We propose that slow waves during non-rapid eye movement sleep could be an electrophysiological marker of the deviant cortical maturation in autism linked to an atypical functioning of thalamo-cortical networks.