Improvement of saccadic functions after dosing with methadone in opioid addicted individuals

Abstract

In the current experiment, we used the saccadometric test to study the effect of a single therapeutic dose of methadone on the integrity of cortico-subcortical brain functioning. In this prospective study, we used the Saccadometer System (Advanced Clinical Instrumentation, Cambridge, UK). The saccadometric test was performed before and 1.5 hours after methadone dosing. We analyzed the following saccadic parameters: latency, duration, amplitude, average and peak velocity, and processing performance (promptness) as well as a number of different types of saccades (like correct/incorrect, under/overshoot, and left-sided/right-sided). The sample consists of 40 subjects with an average 18 years of opioid addiction. The mean age is 35.3 ± 7 (80% males and 20% females). The mean period of heroin dependence is 15.3 ± 6.3 years. The mean daily dose of methadone in substitution therapy is 90 ± 26.5 mg. After administration of a single therapeutic dose of methadone, there were statistically significant differences in the values of saccade duration and latency when compared to the values before the drug administration. Average duration of saccade was significantly longer [51.40 ± 8.75 ms versus 48.93 ± 6.91 ms, z = 2.53, p = .01] and average latency was significantly longer [198.85 ± 52.57 ms versus 183.05 ± 30.95 ms, z = 2.09 p < .03]. This is the first study to test the therapeutic effect of daily methadone dosing on the integrity of the cortico-subcortical brain functions as measured by the saccadometry. More research is needed to explore the effect of illicit opioid use on the integrity of brain structures and functions, and the protective effect of opioid agonist therapy on reversing the damaging effects of illicit opioid use.

Evaluation of Risk Behavior in Gambling Addicted and Opioid Addicted Individuals

“…The evidence, collected by inter alia authors of this paper, suggests that both opioid addicted and gambling addicted individuals can be characterized with higher levels of risk behavior in comparison to healthy people (Brevers et al, 2013;Gorzelańczyk et al, 2014). It has been shown that the administration of substitution drugs can reduce cravings for opioids and also decrease risky decision making among individuals addicted to opioids (Gorzelańczyk et al, 2014;Hu et al, 2019;Kriegler et al, 2019;Kelty et al, 2020).…”

“…It has been observed that the substitution drug (methadone) reduces the level of risky behavior in opioid addicts (Gorzelańczyk et al, 2014). It is interesting to see whether the decision-making strategy before administration of the substitution drug is similar in opioid addicts to the strategy in those who are addicted to gambling and whether the decisionmaking strategy after administration of the drug is similar to healthy individuals, which has been stated in inter alia: (King et al, 2015;Gallimberti et al, 2016).…”

“…The evidence, collected by inter alia authors of this paper, suggests that both opioid addicted and gambling addicted individuals can be characterized with higher levels of risk behavior in comparison to healthy people (Brevers et al, 2013;Gorzelańczyk et al, 2014). It has been shown that the administration of substitution drugs can reduce cravings for opioids and also decrease risky decision making among individuals addicted to opioids (Gorzelańczyk et al, 2014;Hu et al, 2019;Kriegler et al, 2019;Kelty et al, 2020). Although it is suggested that the neurobiological basis of addiction is similar, it is possible to assume that the risk behavior in individuals addicted to opioids can differ from gambling addicted individuals (Zeng et al, 2016;Chen et al, 2017;Coppola et al, 2017;Majuri et al, 2017;Schwaninger et al, 2017;Victorri-Vigneau et al, 2018;Kim et al, 2019).…”

“…The authors introduced for the first time the response time measurement in the IGT test as a new parameter. Response time is assessed for correct and incorrect choices and can be useful in the differential diagnosis of addicts Gorzelańczyk et al (2014).…”

“…It is known that the use of psychoactive substances can change structures and functions of circuits involved in risk decision making (Gilman et al, 2015). The structural and functional changes of the elements of the cortico-subcortical loops have been observed among addicted people (Gorzelańczyk et al, 2014(Gorzelańczyk et al, , 2016Tarnowska et al, 2018).…”