What are the consequences of Methylphenidate exposure for maternally separated rats?

Methylphenidate (MPH) abuse is prevalent among youth. Drug abuse results in pain perception. We sought to investigate whether Maternal separation (MS) prone to MPH addiction. The next question was whether MPH abusers with MS differ in pain perception. We investigated the impact of MS on addiction and drug reward as well as pain perception following 5 days of MPH injection in males and females rats. Initially, rats underwent MS protocol of 3 hr daily for 21 days. Conditioned place preference (CPP) test was an attempt to investigate whether MS rats experience more reward with MPH. The protocol consisted of 10 min habituation on Day 1, conditioning on Day 2-Day 6 (5 mg per kg MPH injection in drug compartment and saline in saline compartment with 4 hr gap between injections) and 10 min test on Day 7. Furthermore, using another group, differences in pain perception were investigated after 5 days of daily MPH injection with 5 mg per kg. Sensory pain sensitivity was tested on PND 39 using tail flick and hotplate in MS and control groups with and without MPH exposure. Results indicated that female rats are equally prone to addiction in CPP. On the other hand, MS males experience a higher reward in CPP. In tail flick test, female MS rats exposed to MPH show a lower sensory pain threshold with similar MPH exposure. Experiencing MPH similarly declined hotplate pain perception in MS and controls in the females. Males, on the other hand, did not show any difference in sensory pain tests. According to results one can argue MS is detrimental. MS males experience more reward with MPH, females are equally addiction prone and MS females experience more pain in tail flick. On the other hand pain threshold can decline in hotplate test for both control and MS females that received MPH.

The diversion and misuse of pharmaceutical stimulants: what do we know and why should we care?

AIMS

To examine the literature pertaining to the diversion and misuse of pharmaceutical stimulants.

METHODS

Relevant literature was identified through comprehensive MEDLINE, EMBASE and PubMed searches.

RESULTS

The evidence to date suggests that the prevalence of diversion and misuse of pharmaceutical stimulants varies across adolescent and young adult student populations, but is higher than that among the general population, with the highest prevalence found among adults with attention deficit-hyperactive disorder (ADHD) and users of other illicit drugs. Concerns that these practices have become more prevalent as a result of increased prescribing are not supported by large-scale population surveys. Information on trends in misuse in countries where there have been recent increases in prescription and consumption rates, however, is limited. Little is known about the frequency and chronicity of misuse, or the extent of associated harms, particularly among those populations, i.e. adolescents, young adult student populations, those with ADHD and illicit drug users, where abuse may be more likely to occur.

CONCLUSIONS

Continued monitoring of the diversion and misuse of pharmaceutical stimulants is of major clinical importance. Despite recognition of the abuse liability of these medications, there is a paucity of data on the prevalence, patterns and harms of diversion and misuse among populations where problematic use and abuse may be most likely to occur (e.g. adolescents, young adults, illicit drug users). Comprehensive investigations of diversion and misuse among these populations should be a major research priority, as should the assessment of abuse and dependence criteria among those identified as regular users.

Misuse and diversion of stimulants prescribed for ADHD: a systematic review of the literature

OBJECTIVE

Recent studies have provided variable information on the frequency and context of diversion and the use of nonprescribed and prescribed stimulant medications in adolescent and young adult populations. The purpose of this systematic review of the literature is to evaluate the extent and characteristics of stimulant misuse and diversion in attention-deficit/hyperactivity disorder (ADHD) and non-ADHD individuals.

METHOD

We conducted a systematic review of the literature of available studies looking at misuse and diversion of prescription ADHD medications using misuse, diversion, stimulants, illicit use, and ADHD medications as key words for the search.

RESULTS

We identified 21 studies representing 113,104 subjects. The studies reported rates of past year nonprescribed stimulant use to range from 5% to 9% in grade school- and high school-age children and 5% to 35% in college-age individuals. Lifetime rates of diversion ranged from 16% to 29% of students with stimulant prescriptions asked to give, sell, or trade their medications. Recent work suggests that whites, members of fraternities and sororities, individuals with lower grade point averages, use of immediate-release compared to extended-release preparations, and individuals who report ADHD symptoms are at highest risk for misusing and diverting stimulants. Reported reasons for use, misuse, and diversion of stimulants include to concentrate, improve alertness, "get high," or to experiment.

CONCLUSIONS

The literature suggests that individuals both with and without ADHD misuse stimulant medications. Recent work has begun to document the context, motivation, and demographic profile of those most at risk for using, misusing, and diverting stimulants. The literature highlights the need to carefully monitor high-risk individuals for the use of nonprescribed stimulants and educate individuals with ADHD as to the pitfalls of the misuse and diversion of the stimulants.

Drug use related problems among nonmedical users of prescription stimulants: a web-based survey of college students from a Midwestern university

This college-based study compared nonmedical users of prescription stimulants to other types of drug users regarding drug use related problems. A Web survey was self-administered in 2005 by a probability sample of 3639 full-time undergraduate students (68% response rate) at a large public Midwestern 4-year university in the United States. The survey consisted of measures to assess substance use and misuse, including a modified version of the Drug Abuse Screening Test (DAST-10). Nonmedical users of prescription stimulants were more likely than other drug users to report polydrug use. Nonmedical users of prescription stimulants had over four times greater odds than other drug users to experience three or more DAST-10 items in the past 12 months (AOR=4.61, 95% CI=3.28-6.48). Among nonmedical users of prescription stimulants, those who used prescription stimulants via intranasal and other non-oral routes of administration had greater odds than oral only users to experience three or more DAST-10 items in the past 12 months. The findings of the present study suggest that the majority of nonmedical users of prescription stimulants are polydrug users and should be screened for potential drug abuse or dependence, especially those who report non-oral routes of administration.

Nonmedical use of prescription stimulants among students

Despite the caveats discussed above, national epidemiologic surveys are useful in estimating the prevalence and historical trends of nonmedical use of prescription stimulants. Because it would be difficult and cost-prohibitive to ask several more in-depth questions on these national surveys, other smaller-scale research studies should be undertaken to understand more about the patterns and consequences of nonmedical use of prescription stimulants. The data from the few studies of college students suggest college students are more likely to use prescription stimulants than their noncollege-attending counterparts and suggest college students may experience a need to stay awake to study given the high level of demands in the college environment. More and more people are taking advantage of the opportunity to go to college, making the selection process more competitive. More data are needed regarding the availability of prescription stimulants on college campuses and, in particular, the availability and use of other types of prescription stimulants other than methylphenidate. Data from the college studies presented here also suggest that, in addition to using prescription stimulants as a study aid, students use prescription stimulants to stay awake longer to party or drink more. Because heavy drinking is known to be associated with a wide variety of negative consequences, it is important to learn more about this particular interaction so that appropriate prevention initiatives can be developed.

Characteristics of adolescents and young adults with ADHD who divert or misuse their prescribed medications

OBJECTIVE

Little is known about the risks and characteristics of attention-deficit/hyperactivity disorder (ADHD) patients who misuse or divert their stimulant medications. As part of a 10-year longitudinal study of youths with ADHD, the authors evaluated medication diversion or misuse at the last follow-up period.

METHOD

Structured psychiatric interviews for diagnosis and a self-report questionnaire regarding medication use in medicated subjects with ADHD compared with controls without ADHD receiving psychotropics for non-ADHD treatment were employed.

RESULTS

Of 98 subjects receiving psychotropic medications (mean age of 20.8 +/- 5 years), 55 (56%) were ADHD subjects and 43 (44%) were controls receiving medications for other purposes. The authors found that 11% of the ADHD group reported selling their medications compared with no subjects in the control group (z = 0.00, p <.05). An additional 22% of the ADHD group reported misusing their medications compared with 5% of the control subjects (z = 1.7 p =.09) and that those with conduct or substance use disorders accounted for the misuse and diversion. A minority of subjects reported escalating their doses and concomitant use with alcohol and drugs.

CONCLUSIONS

The data indicate that the majority of ADHD individuals, particularly those without conduct or substance use disorders, use their medications appropriately. The authors' findings also highlight the need to monitor medication use in ADHD individuals with conduct and/or substance use disorders and to carefully select agents with a low likelihood of diversion or misuse in this group.