Quality and temporal properties of premonitory urges in patients with skin picking disorder

The relationship between sensory phenomena and interoception across the obsessive-compulsive spectrum: a systematic review

BACKGROUND

Uncomfortable sensations preceding repetitive behaviours, known as sensory phenomena, have been documented across the obsessive-compulsive spectrum. Indirect evidence suggests altered interoception may play a role in these shared experiences of sensory phenomena; however, research explicitly measuring this relationship is limited. The current systematic review aimed to establish the nature of sensory phenomena and interoception in obsessive-compulsive and related disorders (OCRDs) and tic disorders as potential maintaining factors of these disorders.

METHODS

PsycINFO, PubMed, and Scopus databases were searched from 2007 to April 2024, yielding 65 studies.

RESULTS

While the majority of studies presented low risk of bias, significant overlap and ambiguity characterised the measurement and conceptualisation of sensory phenomena and interoception. Overall, higher sensory phenomena was associated with greater symptom severity in several obsessive-compulsive spectrum disorders. Obsessive-compulsive disorder and tic disorder samples were characterised by lower interoceptive accuracy, with mixed findings on interoceptive sensibility. Some limited research emerged suggesting altered interoceptive abilities may be associated with greater sensory phenomena in obsessive-compulsive disorder and tic disorders.

CONCLUSIONS

Sensory phenomena are experienced across the obsessive-compulsive spectrum. Future research should explore interoceptive abilities across the OCRDs, and build upon evidence supporting a relationship between sensory phenomena and interoception in OCD and tic disorders.

TRIAL REGISTRATION

CRD42023422817.

Interoception, emotion regulation strategies and skin-picking behaviors - Results of an intensive longitudinal study

Compulsive skin-picking is associated with emotion regulation difficulties, whose origins remain unclear. Interoception, plays an important role in effective emotion regulation. This study examined the relationship between interoception, emotion regulation strategies, and skin-picking in 136 individuals (85% women, aged 18-41), including 71 engaging in skin-picking and 65 psychologically healthy controls. We were interested in between-group differences in maladaptive and adaptive emotion regulation and aspects of interoception as well as associations of the latter with skin-picking symptoms and use of emotion regulation strategies. At baseline, we assessed habitual emotion regulation strategies (rumination, suppression, distraction, engagement, arousal control, reappraisal) and Interoceptive Sensibility (e.g., emotional awareness, body listening, self-regulation, noticing) through self-report questionnaires. Moreover, Interoceptive Accuracy (IAc) was measured via a Heartbeat Counting Task. Additionally, Ecological Momentary Assessment (EMA) over seven days was used to register use of emotion regulation strategies and the occurrence and severity of skin-picking episodes during that period. At baseline, the skin-picking group exhibited lower IAc, emotional awareness, and higher habitual use of rumination than control group. Lower IAc was associated with higher odds of reporting skin-picking episodes assessed during EMA. Body listening correlated with a reduced sense of control over skin-picking during EMA. In total sample, self-regulation was related to lower odds of using rumination during EMA and noticing with less use of cognitive reappraisal. The study highlights the complex relationship between interoception, emotion regulation, and skin-picking, offering new insights into the mechanisms underlying skin picking disorder.

Non-invasive Brain Stimulation for the Treatment of Gilles de la Tourette Syndrome

Gilles de la Tourette Syndrome is a multifaceted neuropsychiatric disorder typically commencing in childhood and characterized by motor and phonic tics. Its pathophysiology is still incompletely understood. However, there is convincing evidence that structural and functional abnormalities in the basal ganglia, in cortico-striato-thalamo-cortical circuits, and some cortical areas including medial frontal regions and the prefrontal cortex as well as hyperactivity of the dopaminergic system are key findings. Conventional therapeutic approaches in addition to counseling comprise behavioral treatment, particularly habit reversal therapy, oral pharmacotherapy (antipsychotic medication, alpha-2-agonists) and botulinum toxin injections. In treatment-refractory Tourette syndrome, deep brain stimulation, particularly of the internal segment of the globus pallidus, is an option for a small minority of patients. Based on pathophysiological considerations, non-invasive brain stimulation might be a suitable alternative. Repetitive transcranial magnetic stimulation appears particularly attractive. It can lead to longer-lasting alterations of excitability and connectivity in cortical networks and inter-connected regions including the basal ganglia through the induction of neural plasticity. Stimulation of the primary motor and premotor cortex has so far not been shown to be clinically effective. Some studies, though, suggest that the supplementary motor area or the temporo-parietal junction might be more appropriate targets. In this manuscript, we will review the evidence for the usefulness of repetitive transcranial magnetic stimulation and transcranial electric stimulation as treatment options in Tourette syndrome. Based on pathophysiological considerations we will discuss the rational for other approaches of non-invasive brain stimulation including state informed repetitive transcranial magnetic stimulation.

Sensory symptoms in body-focused repetitive behaviors, restless legs syndrome, and Tourette syndrome: An overlap?

Tourette syndrome (TS) is a neurodevelopmental condition characterized by multiple tics. Sensory symptoms play a key role in the clinical phenomenology and pathophysiology of TS, as most patients report premonitory urges driving tic expression. Interestingly, sensory symptoms have also been reported in other conditions characterized by repeated behaviors. This review explores the nature of sensory symptoms reported by patients with body focused repetitive behaviors (BFRBs, especially trichotillomania and skin picking disorder) and restless legs syndrome (RLS) in comparison to TS. A sense of mounting inner tension and reinforcement mechanisms driven by gratification and relief on expression of the tic or repetitive behavior appear to be implicated across all conditions. Subjective urges can be temporarily suppressed by patients with TS and selected BFRBs, whereas patients with RLS tend to report dysesthesia more frequently than a suppressible urge to move. The observed similarities in the phenomenology of sensory symptoms across these conditions raise the possibility of a comparable underlying pathophysiology. Preliminary findings suggest an overlap of neural pathways encompassing the insula, basal ganglia (putamen), and posterior cingulate cortex.