Cognitive Impairments in Abstinent Male Residents of a Therapeutic Community for Substance-Use Disorders: A Five-Year Retrospective Study

Transcranial direct current stimulation combined with cognitive training improves decision making and executive functions in opioid use disorder: a triple-blind sham-controlled pilot study

Opioid use disorder (OUD) is a chronic disorder with a considerable amount of morbidity and mortality. Despite remarkable improvement achieved by maintenance programs, an array of treatment goals were still unmet. Mounting evidence suggests that transcranial Direct Current Stimulation (tDCS) improves decision making and cognitive functions in addictive disorders. tDCS paired with a decision making task was depicted to diminish impulsivity as well.

The present study aimed to assess the effect of tDCS combined with cognitive training (CT) in OUD for the first time.

In this triple-blind randomized sham-controlled pilot study, 38 individuals with OUD from the Buprenorphine-Naloxone Maintenance Therapy program were administered 20-minutes of 2 mA active/sham tDCS over the dorsolateral prefrontal cortex with concomitant cognitive training. A selected test battery evaluating decision making under risk and ambiguity as well as executive functions, verbal fluency and working memory was utilized before and after the intervention.

Greater improvements were observed in decision making under ambiguity (p = 0.016), set shifting ability and alternating fluency while no improvements were observed in decision making under risk in the active group, compared to sham.

Deficits of decision making and executive functions have a pivotal role in the perpetuation and the relapse of the OUD. Alleviation of these impairments brought tDCS/CT forth as an expedient neuroscientifically-grounded treatment option that merits further exploration in OUD, Trial registration: NCT05568251.

Attention-Deficit/Hyperactivity Disorder Symptoms, Sensation-Seeking, and Sensory Modulation Dysfunction in Substance Use Disorder: A Cross Sectional Two-Group Comparative Study

Background: Attention-deficit/hyperactivity disorder (ADHD) and sensation-seeking, a trait characterized by risk-related behaviors, have been recognized as risk factors in substance use disorder (SUD). Though ADHD co-occurs with sensory modulation dysfunction (SMD), SMD has scarcely been explored in SUD. Thus, this study aimed to characterize ADHD symptomology, sensation-seeking, and SMD, as well as to explore their contribution to SUD likelihood. Methods: A cross sectional two-group comparative study including therapeutic community residents with SUD (n = 58; study group) and healthy individuals (n = 62; comparison group) applying the MOXO continuous performance test (MOXO-CPT) evaluating ADHD-related symptoms. In addition, participants completed the ADHD Self-Report Scale—Version 1.1 for ADHD screening; the Brief Sensation Seeking Scale quantifying risk-taking behaviors; and the Sensory Responsiveness Questionnaire-Intensity Scale for identifying SMD. Results: The study group demonstrated higher SMD incidence (53.57% vs. 14.52%) and lower performance in three MOXO-CPT indexes: Attention, Impulsivity, and Hyperactivity, but not in Timing, compared to the comparison group. Sensory over-responsiveness had the strongest relationship with SUD, indicating 27-times increased odds for SUD (95% CI = 5.965, 121.216; p ≤ 0.0001). A probability risk index is proposed. Conclusion: We found SMD with the strongest relation to SUD exceeding that of ADHD, thus contributing a new perspective for developing future therapeutic modalities. Our findings highlight the need to address SMD above and beyond ADHD symptomology throughout the SUD rehabilitation.

Cognitive reserve mediates the severity of certain neuropsychological deficits related to cocaine use disorder

The concept of cognitive reserve (CR) is being considered in the field of substance use disorder (SUD) by observing that there are individuals whose brain alterations are not related to the cognitive symptomatology they present. Our aims were to characterise the possible neuropsychological deficits in a sample of subjects with SUD compared to healthy controls and to determine whether the degree of CR is a mediator in the cognitive functioning of these patients. To perform these objectives, the study involved a sample of subjects with SUD in outpatient treatment and a healthy control group. A CR questionnaire and a comprehensive neuropsychological assessment were administered, and we also collected data related to drug consumption and psychological well-being. The SUD group showed poorer performance compared to the control group in several cognitive domains (attention, declarative memory, executive functions and emotional perception), as well as in psychological comfort. Interestingly, we observed that the deficits found in attention and processing speed were highly mediated by the CR level of the participants, an effect that we did not observe in the rest of the variables registered. Our results suggest that long-term drug consumption leads to cognitive deficits and affects the psychological well-being of the subjects. Moreover, the CR should be taken into account during the assessment and rehabilitation of patients with SUD due to its protective role against certain neuropsychological deficits.