Neuromodulation to Treat Substance Use Disorders in People With Schizophrenia and Other Psychoses: A Systematic Review

Royal Australian and New Zealand College of Psychiatrists professional practice guidelines for the administration of repetitive transcranial magnetic stimulation

OBJECTIVES

To provide guidance for the optimal administration of repetitive transcranial magnetic stimulation, based on scientific evidence and supplemented by expert clinical consensus.

METHODS

Articles and information were sourced from existing guidelines and published literature. The findings were then formulated into consensus-based recommendations and guidance by the authors. The guidelines were subjected to rigorous successive consultation within the RANZCP, involving the Section of ECT and Neurostimulation (SEN) Committee, its broader membership and expert committees.

RESULTS

The RANZCP professional practice guidelines (PPG) for the administration of rTMS provide up-to-date advice regarding the use of rTMS in clinical practice. The guidelines are intended for use by psychiatrists and non-psychiatrists engaged in the administration of rTMS to facilitate best practice to optimise outcomes for patients. The guidelines strive to find the appropriate balance between promoting best evidence-based practice and acknowledging that evidence for rTMS use is a continually evolving.

CONCLUSION

The guidelines provide up-to-date advice for psychiatrists and non-psychiatrists to promote optimal standards of rTMS practice.

Endorsement of psychotic-like experiences and problematic cannabis use associated with worse executive functioning performance in undergraduates

BACKGROUND

Emerging adults who endorse more positive psychotic-like experiences (PLEs; bizarre experiences, delusional ideations) may experience greater cannabis-related impairments in executive function. Negative and depressive PLEs are also associated with cannabis use, however, less is known about their relation to executive functioning. Here, we hypothesize that high positive PLEs and cannabis use are associated with worse performance on computerized versions of the Iowa Gambling Task (IGT) and the Card Sorting Task (CST); exploratory analyses are conducted with negative and depressive PLEs.

METHODS

We recruited university students (N = 543) who completed an online study consisting of self-report measures of problematic cannabis use (Cannabis Use Disorder Identification Test; CUDIT-R) and PLEs (Community Assessment of Psychotic Experiences; CAPE). Of these, n=270 completed the CST and n=251 completed the IGT.

RESULTS

Problematic cannabis use and high endorsement of positive PLEs related to significantly worse performance on the IGT and greater perseverative errors on the CST. In addition, people who endorsed high levels of positive PLEs were also significantly more likely to complete the IGT with less money relative to those who endorsed fewer PLEs, regardless of cannabis use. Further analyses based on negative PLEs revealed a similar pattern for perseverative errors on the CST; depressive PLEs were not related to task performance.

CONCLUSION

Findings highlight that problematic cannabis use and more frequent and distressing positive PLEs are associated with poorer executive functioning. Thus, executive functioning may have implications for intervention among those high on both attributes, who are at high risk of onset of psychosis.

Managing substance use in patients receiving therapeutic repetitive transcranial magnetic stimulation: A scoping review

Repetitive Transcranial Magnetic Stimulation (rTMS) is an invaluable treatment option for neuropsychiatric disorders. Co-occurring recreational and nonmedical substance use can be common in those presenting for rTMS treatment, and it is unknown how it may affect the safety and efficacy of rTMS for the treatment of currently approved neuropsychiatric indications. This scoping review aimed to map the literature on humans receiving rTMS and had a history of any type of substance use. The search identified 274 articles providing information on inclusion/exclusion criteria, withdrawal criteria, safety protocols, type of rTMS and treatment parameters, adverse events and effect on primary outcomes that related to substance use. There are neurophysiological effects of substance use on cortical excitability, although the relevance to clinical rTMS practice is unknown. The current literature supports the safety and feasibility of delivering rTMS to those who have co-occurring neuropsychiatric disorder and substance use. However, specific details on how varying degrees of substance use alters the safety, efficacy, and mechanisms of rTMS remains poorly described.

Network Analysis of the Structure of the Core Symptoms and Clinical Correlates in Comorbid Schizophrenia and Gambling Disorder

Few studies have analyzed the clinical profile of treatment-seeking patients with the comorbid presence of schizophrenia (SCZ) and gambling disorder (GD), which warrants new research to assess the network structure of this complex mental condition. The aim of this study was to explore the organization of the symptoms and other clinical correlates of SCZ with GD. Network analysis was applied to a sample of N = 179 SCZ patients (age range: 19-70 years, mean=39.5, SD=9.9) who met clinical criteria for gambling disorder-related problems. Variables included in the network were the core GD symptoms according to the DSM-5, psychotic and paranoid ideation levels, global psychological distress, GD severity measures (debts and illegal behavior related with gambling), substances (tobacco, alcohol, and illegal drugs), and personality profile. The nodes with the highest authority in the network (variables of highest relevance) were personality traits and psychological distress. Four empirical modules/clusters were identified, and linkage analysis identified the nodes with the highest closeness (bridge nodes) to be novelty seeking and reward dependence (these traits facilitate the transition between the modules). Identification of the variables with the highest centrality/linkage can be particularly useful for developing precise management plans to prevent and treat SCZ with GD.

Supplementary Information

The online version contains supplementary material available at 10.1007/s11469-022-00983-y.

Neurocognitive moderation of repetitive transcranial magnetic stimulation (rTMS) effects on cannabis use in schizophrenia: a preliminary analysis

Repetitive transcranial magnetic stimulation (rTMS) is a promising treatment for cannabis use disorder in schizophrenia; however, gaps in the literature remain as to the potential role of neurocognitive functioning in treatment response. We evaluated the moderating role of select cognitive functions including baseline executive functioning, verbal memory, and sustained attention, and we explore the mediating role of changes in task performance on changes in cannabis use in both active and sham rTMS groups. Participants underwent high-frequency (20 Hz) rTMS applied to the bilateral dorsolateral prefrontal cortex 5x/week for 4 weeks. Weekly self-report of cannabis use and semi-quantitative urinary carboxy-tetrahydrocannabinol levels were recorded. A neurocognitive battery assessing verbal memory, visuospatial working memory, verbal working memory, sustained attention, delayed discounting, and complex planning was administered pre- and post-treatment. Better baseline performance on tasks assessing sustained attention, delayed discounting, and complex planning moderated the extent to which participants in the active group reduced cannabis use. There were no significant indirect pathways between treatment, changes in neuropsychological performance, and changes in cannabis use; however, active rTMS improved complex planning and sustained attention. These preliminary findings suggest that there is a moderating role of sustained attention, delayed discounting, and complex planning on the effects of rTMS on cannabis use. Further, mediation models suggest rTMS may exert direct effects on cannabis use independent of its effects on cognitive functioning in people with SCZ. Trial Registration: clinicaltrials.gov: NCT03189810.