Arousal and drug abuse

The Utility of Neuromuscular Assessment to Identify ADHD Among Patients with a Complex Symptom Picture

OBJECTIVE

Diagnostic assessment of ADHD is challenging due to comorbid psychopathologies and symptoms overlapping with other psychiatric disorders. In this study, we investigate if a distinct pattern of neuromuscular dysregulation previously reported in ADHD, can help identifying ADHD in psychiatric patients with diverse and complex symptoms.

METHOD

We explored the impact of neuromuscular dysregulation, as measured by The Motor Function Neurologic Assessment (MFNU), on the likelihood of being diagnosed with ADHD, affective disorder, anxiety disorder, or personality disorder among adults (n = 115) referred to a psychiatric outpatient clinic.

RESULTS

Logistic regression revealed that neuromuscular dysregulation was significantly associated with ADHD diagnosis only (OR 1.15, p < .01), and not with affective-, anxiety-, or personality disorders. Sensitivity and specificity for ADHD at different MFNU scores is provided.

CONCLUSIONS

A test of neuromuscular dysregulation may promote diagnostic accuracy in differentiating ADHD from other psychiatric disorders in patients with an overlapping symptom picture. This may have important implications for clinical practice. More studies are needed.

Gender-Specific Interactions in a Visual Object Recognition Task in Persons with Opioid Use Disorder

Opioid use disorder (OUD)-associated overdose deaths have reached epidemic proportions worldwide over the past two decades, with death rates for men reported at twice the rate for women. Using a controlled, cross-sectional, age-matched (18-56 y) design to better understand the cognitive neuroscience of OUD, we evaluated the electroencephalographic (EEG) responses of male and female participants with OUD vs. age- and gender-matched non-OUD controls during a simple visual object recognition Go/No-Go task. Overall, women had significantly slower reaction times (RTs) than men. In addition, EEG N200 and P300 event-related potential (ERP) amplitudes for non-OUD controls were significantly larger for men, while their latencies were significantly shorter than for women. However, while N200 and P300 amplitudes were not significantly affected by OUD for either men or women in this task, latencies were also affected differentially in men vs. women with OUD. Accordingly, for both N200 and P300, male OUD participants exhibited longer latencies while female OUD participants exhibited shorter ones than in non-OUD controls. Additionally, robust oscillations were found in all participants during a feedback message associated with performance in the task. Although alpha and beta power during the feedback message were significantly greater for men than women overall, both alpha and beta oscillations exhibited significantly lower power in all participants with OUD. Taken together, these findings suggest important gender by OUD differences in cognitive processing and reflection of performance in this simple visual task.

Music therapy for people with substance use disorders

BACKGROUND

Substance use disorder (SUD) is the continued use of one or more psychoactive substances, including alcohol, despite negative effects on health, functioning, and social relations. Problematic drug use has increased by 10% globally since 2013, and harmful use of alcohol is associated with 5.3% of all deaths. Direct effects of music therapy (MT) on problematic substance use are not known, but it may be helpful in alleviating associated psychological symptoms and decreasing substance craving.

OBJECTIVES

To compare the effect of music therapy (MT) in addition to standard care versus standard care alone, or to standard care plus an active control intervention, on psychological symptoms, substance craving, motivation for treatment, and motivation to stay clean/sober.

SEARCH METHODS

We searched the following databases (from inception to 1 February 2021): the Cochrane Drugs and Alcohol Specialised Register; CENTRAL; MEDLINE (PubMed); eight other databases, and two trials registries. We handsearched reference lists of all retrieved studies and relevant systematic reviews.

SELECTION CRITERIA

We included randomised controlled trials comparing MT plus standard care to standard care alone, or MT plus standard care to active intervention plus standard care for people with SUD.

DATA COLLECTION AND ANALYSIS

We used standard Cochrane methodology.

MAIN RESULTS

We included 21 trials involving 1984 people. We found moderate-certainty evidence of a medium effect favouring MT plus standard care over standard care alone for substance craving (standardised mean difference (SMD) -0.66, 95% confidence interval (CI) -1.23 to -0.10; 3 studies, 254 participants), with significant subgroup differences indicating greater reduction in craving for MT intervention lasting one to three months; and small-to-medium effect favouring MT for motivation for treatment/change (SMD 0.41, 95% CI 0.21 to 0.61; 5 studies, 408 participants). We found no clear evidence of a beneficial effect on depression (SMD -0.33, 95% CI -0.72 to 0.07; 3 studies, 100 participants), or motivation to stay sober/clean (SMD 0.22, 95% CI -0.02 to 0.47; 3 studies, 269 participants), though effect sizes ranged from large favourable effect to no effect, and we are uncertain about the result. There was no evidence of beneficial effect on anxiety (mean difference (MD) -0.17, 95% CI -4.39 to 4.05; 1 study, 60 participants), though we are uncertain about the result. There was no meaningful effect for retention in treatment for participants receiving MT plus standard care as compared to standard care alone (risk ratio (RR) 0.99, 95% 0.93 to 1.05; 6 studies, 199 participants). There was a moderate effect on motivation for treatment/change when comparing MT plus standard care to another active intervention plus standard care (SMD 0.46, 95% CI -0.00 to 0.93; 5 studies, 411 participants), and certainty in the result was moderate. We found no clear evidence of an effect of MT on motivation to stay sober/clean when compared to active intervention, though effect sizes ranged from large favourable effect to no effect, and we are uncertain about the result (MD 0.34, 95% CI -0.11 to 0.78; 3 studies, 258 participants). There was no clear evidence of effect on substance craving (SMD -0.04, 95% CI -0.56 to 0.48; 3 studies, 232 participants), depression (MD -1.49, 95% CI -4.98 to 2.00; 1 study, 110 participants), or substance use (RR 1.05, 95% CI 0.85 to 1.29; 1 study, 140 participants) at one-month follow-up when comparing MT plus standard care to active intervention plus standard care. There were no data on adverse effects. Unclear risk of selection bias applied to most studies due to incomplete description of processes of randomisation and allocation concealment. All studies were at unclear risk of detection bias due to lack of blinding of outcome assessors for subjective outcomes (mostly self-report). We judged that bias arising from such lack of blinding would not differ between groups. Similarly, it is not possible to blind participants and providers to MT. We consider knowledge of receiving this type of therapy as part of the therapeutic effect itself, and thus all studies were at low risk of performance bias for subjective outcomes.  We downgraded all outcomes one level for imprecision due to optimal information size not being met, and two levels for outcomes with very low sample size.  AUTHORS' CONCLUSIONS: Results from this review suggest that MT as 'add on' treatment to standard care can lead to moderate reductions in substance craving and can increase motivation for treatment/change for people with SUDs receiving treatment in detoxification and short-term rehabilitation settings. Greater reduction in craving is associated with MT lasting longer than a single session. We have moderate-to-low confidence in our findings as the included studies were downgraded in certainty due to imprecision, and most included studies were conducted by the same researcher in the same detoxification unit, which considerably impacts the transferability of findings.

Sleep and alertness disturbance and substance use disorders: A bi-directional relation

The majority of the literature describing the relation of sleep/alertness disturbance and substance use disorders (SUD) has focused on the disruptive effects of substances with abuse liability on sleep and alertness. Rarely have studies or literature reviews assessed or discussed how sleep/alertness disturbance affects substance use. This paper focuses on the sleep/alertness disturbance side of the relation. We argue that the relation is bi-directional and review evidence showing that sleep/alertness disturbance affects all phases of the addiction cycle, including the initiation, maintenance and relapse of SUD. We review a variety of substances across all phases of the addiction cycle and conclude sleep/alertness disturbance is a critical factor in both understanding and treating SUD.

Prepronociceptin-Expressing Neurons in the Extended Amygdala Encode and Promote Rapid Arousal Responses to Motivationally Salient Stimuli

Motivational states consist of cognitive, emotional, and physiological components controlled by multiple brain regions. An integral component of this neural circuitry is the bed nucleus of the stria terminalis (BNST). Here, we identify that neurons within BNST that express the gene prepronociceptin (Pnoc^BNST) modulate rapid changes in physiological arousal that occur upon exposure to motivationally salient stimuli. Using in vivo two-photon calcium imaging, we find that Pnoc^BNST neuronal responses directly correspond with rapid increases in pupillary size when mice are exposed to aversive and rewarding odors. Furthermore, optogenetic activation of these neurons increases pupillary size and anxiety-like behaviors but does not induce approach, avoidance, or locomotion. These findings suggest that excitatory responses in Pnoc^BNST neurons encode rapid arousal responses that modulate anxiety states. Further histological, electrophysiological, and single-cell RNA sequencing data reveal that Pnoc^BNST neurons are composed of genetically and anatomically identifiable subpopulations that may differentially tune rapid arousal responses to motivational stimuli.

Cannabidiol Partially Blocks the Excessive Sleepiness in Hypocretindeficient Rats: Preliminary Data

BACKGROUND

Excessive daytime sleepiness and cataplexy are among the symptoms of narcolepsy, a sleep disorder caused by the loss of hypocretin/orexin (HCRT/OX) neurons placed into the Hypothalamus (LH). Several treatments for managing narcolepsy include diverse drugs to induce alertness, such as antidepressants, amphetamine, or modafinil, etc. Recent evidence has shown that cannabidiol (CBD), a non-psychotropic derived from Cannabis sativa, shows positive therapeutic effects in neurodegenerative disorders, including Parkinson´s disease. Furthermore, CBD provokes alertness and enhances wake-related neurochemicals in laboratory animals. Thus, it is plausible to hypothesize that excessive somnolence observed in narcolepsy might be blocked by CBD.

OBJECTIVE

Here, we determined whether the systemic injection of CBD (5mg/kg, i.p.) would block the excessive sleepiness in a narcoleptic model.

METHODS

To test this idea, the neurotoxin hypocretin-2-saporin (HCRT2/SAP) was bilaterally injected into the LH of rats to eliminate HCRT leading to the establishment of narcoleptic-like behavior. Since excessive somnolence in HCRT2/SAP lesioned rats has been observed during the lights-off period, CBD was administered at the beginning of the dark phase.

RESULTS

Hourly analysis of sleep data showed that CBD blocked the sleepiness during the lights-off period across 7h post-injection in lesioned rats.

CONCLUSION

Taking together, these preliminary findings suggest that CBD might prevent sleepiness in narcolepsy.

Modulating the immune response with the wake-promoting drug modafinil: A potential therapeutic approach for inflammatory disorders

Modafinil is a psychostimulant drug approved by the FDA primarily for the treatment of sleep disorders such as narcolepsy, excessive daytime sleepiness and sleep apnea. Several documented but not yet approved uses for modafinil have been described over the last 30 years, including alleviating fatigue in neurological and neurodegenerative disorders. Recent evidence has suggested that modafinil may have an immunomodulatory effect. Here, we review the different effects of modafinil treatment in animal models of brain inflammation and peripheral immune function. We conclude that there is unequivocal evidence of an anti-inflammatory effect of modafinil in experimental animal models of brain inflammation and neurodegenerative disorders, including systemic inflammation and methamphetamine-induced neuroinflammation, Parkinson's disease, brain ischemia, and multiple sclerosis. Modafinil acts on resident glial cells and infiltrating immune cells, negatively affecting both innate and adaptive immune responses in the brain. We also review the outcomes of modafinil treatment on peripheral immune function. The results of studies on this subject are still controversial and far from conclusive, but point to a new avenue of research in relation to peripheral inflammation. The data reviewed here raise the possibility of modafinil being used as adjuvant treatment for neurological disorders in which inflammation plays an important role.

Pharmacokinetic and pharmacodynamic of the cognitive enhancer modafinil: Relevant clinical and forensic aspects

Modafinil is a nonamphetamine nootropic drug with an increasingly therapeutic interest due to its different sites of action and behavioral effects in comparison to cocaine or amphetamine. A review of modafinil (and of its prodrug adrafinil and its R-enantiomer armodafinil) chemical, pharmacokinetic, pharmacodynamic, toxicological, clinical and forensic aspects was performed, aiming to better understand possible health problems associated to its unconscious and unruled use. Modafinil is a racemate metabolized mainly in the liver into its inactive acid and sulfone metabolites, which undergo primarily renal excretion. Although not fully clarified, major effects seem to be associated to inhibition of dopamine reuptake and modulation of several other neurochemical pathways, namely noradrenergic, serotoninergic, orexinergic, histaminergic, glutamatergic and GABAergic. Due its wake-promoting effects, modafinil is used for the treatment of daily sleepiness associated to narcolepsy, obstructive sleep apnea and shift work sleep disorder. Its psychotropic and cognitive effects are also attractive in several other pathologies and conditions that affect sleep structure, induce fatigue and lethargy, and impair cognitive abilities. Additionally, in health subjects, including students, modafinil is being used off-label to overcome sleepiness, increase concentration and improve cognitive potential. The most common adverse effects associated to modafinil intake are headache, insomnia, anxiety, diarrhea, dry mouth and raise in blood pressure and heart rate. Infrequently, severe dermatologic effects in children, including maculopapular and morbilliform rash, erythema multiforme and Stevens-Johnson Syndrome have been reported. Intoxication and dependence associated to modafinil are uncommon. Further research on effects and health implications of modafinil and its analogs is steel needed to create evidence-based policies.