Misuse of pain medication is pathway to high-risk behaviors, study finds

ScienceDaily (July 24, 2011) — A new study by researchers at Drexel University's School of Public Health suggests that abuse of prescription painkillers may be an important gateway to the use of injected drugs such as heroin, among people with a history of using both types of drugs.

The study, published in the International Journal of Drug Policy, explores factors surrounding young injection drug users' initiation into the misuse of opioid drugs. Common factors identified in this group included a family history of drug misuse and receiving prescriptions for opioid drugs in the past. The results support a need for efforts to prevent misuse of prescription drugs, particularly during adolescence.

"Participants were commonly raised in household where misuse of prescription drugs, illegal drugs, or alcohol, was normalized," explains Dr. Stephen Lankenau, an associate professor in the School of Public Health and principal investigator of the study. "Access to prescription medications -- either from a participant's own source, a family member, or a friend -- was a key feature of initiation into prescription drug misuse."

In numerous cases, the desire to experiment with a prescription opioid drug (the common class of drugs that includes codeine and oxycodone), combined with financial incentives or pressures from friends to sell available quantities, resulted in escalated patterns of opioid misuse, according to the study.

Lankenau and colleagues also describe two key findings as evidence of an emerging dynamic among misuse of opioid drugs and the use of injection drugs. First, four of five IDUs misused an opioid before injecting heroin, in contrast to more conventional patterns of using opioids as a substitute drug after initiating heroin use.

Second, in nearly one out of four young IDUs in this study, a prescription opioid was the first type of drug they injected. Prescription opioids are rarely reported at initiation into injection drug use amongst young IDUs. All but two of these participants later transitioned into injecting heroin.

Opioid misuse is an important public health concern due to the increasing association of opioids with drug dependence and fatal overdose, and much research has focused on the factors affecting how and when people initially misuse opioids. However, descriptive data about initiation into prescription opioid misuse among young injection drug users are scarce.

To fill this gap, in this study researchers interviewed 50 young IDUs aged 16 and 25 years old in New York and Los Angeles, who had misused a prescription drug at least three times in the past three months, to study contextual factors leading to their use of opioid drugs. Participants were recruited in natural settings, such as parks, streets, and college campuses, during 2008 and 2009. A mixed-methods research design was utilized that collected both quantitative and qualitative data.

Additional findings and descriptors of the study population include:

Most were white, heterosexual males in their early 20sMany did not complete high school, were expelled from school, or held back a gradeNearly all were homeless at some point, most were currently homeless, and most regarded themselves as "travelers," (i.e., moving from city to city in search of work, housing, or adventure)Most had received a psychological diagnosis, such as depression, anxiety, or Attention Deficit Hyperactivity Disorder (ADHD), and many had a history of drug treatmentMost generally regarded prescription opioids as readily accessible, valued commodities that could be traded or soldNearly three-quarters had been prescribed an opioid in their lifetime, which occurred on average at 14.6 years old, often for common ailments such as dental procedures or sports injuriesMost witnessed family members misuse one or more substances during childhood and adolescence, ranging from alcoholism to injecting heroin

The authors conclude that prevention efforts, especially during adolescence, are needed, and that parents and guardians need to carefully monitor and safeguard all prescription medications, particularly opioids, within the household. Although households where drug use is normalized or where broader social or psychological problems exist are more difficult to remedy with prevention efforts or policy changes, future research examining prescription opioid misuse among a range of adolescents and young adults to better understand the contextual and environmental factors of drug use may yield additional solutions.

The article was co-authored by Karol Silva (Drexel University); Michelle Teti (University of Missouri); Alex Harocopos (National Development and Research Institutes); and Jennifer Jackson Bloom and Meghan Treese (Children's Hospital Los Angeles).

Lankenau is also principal investigator of two studies evaluating the effectives of overdose prevention programs in Los Angeles and Philadelphia.

Lankenau is an associate professor in the Department of Community Health & Prevention at the Drexel University School of Public Health. He received his PhD and MA degrees in Sociology from the University of Maryland. He earned his BA in Sociology at the University of Vermont.

Story Source:

The above story is reprinted (with editorial adaptations by ScienceDaily staff) from materials provided by Drexel University.

Journal Reference:

Stephen E. Lankenau, Michelle Teti, Karol Silva, Jennifer Jackson Bloom, Alex Harocopos, Meghan Treese. Initiation into prescription opioid misuse amongst young injection drug users. International Journal of Drug Policy, 2011; DOI: 10.1016/j.drugpo.2011.05.014

Note: If no author is given, the source is cited instead.

Disclaimer: This article is not intended to provide medical advice, diagnosis or treatment. Views expressed here do not necessarily reflect those of ScienceDaily or its staff.

View the original article here

New 'chemical pathway' in the brain for stress: Breakthrough offers hope for targeted treatment of stress-related disorders

ScienceDaily (Apr. 20, 2011) — A team of neuroscientists at the University of Leicester, UK, in collaboration with researchers from Poland and Japan, has announced a breakthrough in the understanding of the 'brain chemistry' that triggers our response to highly stressful and traumatic events.

The discovery of a critical and previously unknown pathway in the brain that is linked to our response to stress is published in the journal Nature. The advance offers new hope for targeted treatment, or even prevention, of stress-related psychiatric disorders.

About 20% of the population experience some form of anxiety disorder at least once in their lives. The cumulative lifetime prevalence of all stress-related disorders is difficult to estimate but is probably higher than 30%.

Dr Robert Pawlak, from the University of Leicester who led the UK team, said: "Stress-related disorders affect a large percentage of the population and generate an enormous personal, social and economic impact. It was previously known that certain individuals are more susceptible to detrimental effects of stress than others. Although the majority of us experience traumatic events, only some develop stress-associated psychiatric disorders such as depression, anxiety or posttraumatic stress disorder. The reasons for this were not clear."

Dr Pawlak added that a lack of correspondence between the commonness of exposure to psychological trauma and the development of pathological anxiety prompted the researchers to look for factors that may make some individuals more vulnerable to stress than others.

"We asked: What is the molecular basis of anxiety in response to noxious stimuli? How are stress-related environmental signals translated into proper behavioural responses? To investigate these problems we used a combination of genetic, molecular, electrophysiological and behavioural approaches. This resulted in the discovery of a critical, previously unknown pathway mediating anxiety in response to stress."

The study found that the emotional centre of the brain -- the amygdala -- reacts to stress by increasing production of a protein called neuropsin. This triggers a series of chemical events which in turn cause the amygdala to increase its activity. As a consequence, a gene is turned on that determines the stress response at a cellular level.

"We then examined behavioural consequences of the above series of cellular events caused by stress in the amygdala," said Dr Pawlak. "Studies in mice revealed that upon feeling stressed, they stayed away from zones in a maze where they felt unsafe. These were open and illuminated spaces they avoid when they are anxious."

"However when the proteins produced by the amygdala were blocked -- either pharmacologically or by gene therapy -- the mice did not exhibit the same traits. The behavioural consequences of stress were no longer present. We conclude that the activity of neuropsin and its partners may determine vulnerability to stress."

Neuropsin was previously discovered by Professor Sadao Shiosaka, a co-author of the paper. This research, for which the bioinformatics modelling was done by Professor Ryszard Przewlocki and his team, has for the first time characterized its mechanism of action in controlling anxiety in the amygdala.

The study took four years to complete, during which scientists from the Department of Cell Physiology and Pharmacology collaborated with colleagues from the Medical Research Council Toxicology Unit at the University of Leicester, the Department of Molecular Neuropharmacology, Polish Academy of Sciences in Krakow, Poland and Nara Institute of Science and Technology in Japan. The work was supported by the European Union, the Medical Research Council and Medisearch -- the Leicestershire Medical Research Foundation. The first author, Benjamin Attwood, sponsored by Medisearch, took 3 years off from his medical studies curriculum to complete the necessary experiments. He commented: "It has been a thoroughly absorbing project to uncover how our experiences can change the way we behave. Hopefully this will lead to help for people that have to live with the damaging consequences of traumatic experiences."

Dr Pawlak added: "We are tremendously excited about these findings. We know that all members of the neuropsin pathway are present in the human brain. They may play a similar role in humans and further research will be necessary to examine the potential of intervention therapies for controlling stress-induced behaviours."

"Although research is now needed to translate our findings to the clinical situation, our discovery opens new possibilities for prevention and treatment of stress-related psychiatric disorders such as depression and posttraumatic stress disorder."

Story Source:

The above story is reprinted (with editorial adaptations by ScienceDaily staff) from materials provided by University of Leicester, via EurekAlert!, a service of AAAS.

Journal Reference:

Benjamin K. Attwood, Julie-Myrtille Bourgognon, Satyam Patel, Mariusz Mucha, Emanuele Schiavon, Anna E. Skrzypiec, Kenneth W. Young, Sadao Shiosaka, Michal Korostynski, Marcin Piechota, Ryszard Przewlocki, Robert Pawlak. Neuropsin cleaves EphB2 in the amygdala to control anxiety. Nature, 2011; DOI: 10.1038/nature09938

Note: If no author is given, the source is cited instead.

Disclaimer: This article is not intended to provide medical advice, diagnosis or treatment. Views expressed here do not necessarily reflect those of ScienceDaily or its staff.

View the original article here