Genetics of addiction and treatment

Drug addiction is often entangled in a lifestyle of violence.  Law enforcement agencies have responded to use of illicit drugs by passing tougher sentencing conditions for trafficking and dealing, tempered with leniency for minor offences.

This strategy has not resulted in a reduction of illicit drug use.  It was once a widely accepted view that addicts lacked the willpower to stop abusing.  As this prejudice is gradually replaced by the understanding that dependency is a chronic, relapsing mental disease that causes compulsive addiction, the relevant legal and health authorities are now promoting rehabilitation as the preferred strategy.

The dependency on illicit drugs and alcohol is a chronic, relapsing mental disease that drives the compulsion and craving for a particular substance.  Patients display behavioural and cognitive symptoms that have a significant impact on their medical and physical wellbeing.  This tends to have a corrosive effect on families and users often find it difficult to contribute to society as socially responsible individuals. The economic burden on the many public health programs, arising from treating the injuries or illness of the destructive persona, is substantial.

It is now widely accepted that this compulsive disease has both genetic and environmental components. Twin and family adoption studies estimate that genes can account for up to 60% of the overall susceptibility to substance dependency.  Studies have implicated susceptibility genes that influence the metabolism of the compounds of interest such as the P450 family as well as genes that are involved in the pathway of substance dependence, for example;  Serotonin and the Dopamine and Opioid receptor families.  In 2010, the first genetic study on patients of Arab ancestry was performed at UWA’s Centre for Forensic Science.  The study was a candidate gene approach that identified associations between several polymorphisms in the Serotonin and Opioid Receptor genes and substance dependency including treatment outcomes.  The work continues with genome wide association studies using microarray and next generation sequencing strategies to consider all genes without prejudice.  The project is a multicentre effort, which will also compare genetic data collected from patients from various rehabilitation centres including Perth.

The comparative effort to assess similarities and differences between ethnic groups is an endeavour to develop diagnostic markers that can be used to promote effective rehabilitation strategies at the point of care.  The genetic information can also be used with public health databases to identify genes in substance dependent patients that are associated with age related morbidity.

Collaborator/s

  • Dr Habiba Al Safar, Khalifa University of Science Technology and Research
  • Dr Ahmed Elkashef, UAE National Rehabilitation Center
  • Professor Gary Hulse, School of Psychiatry and Clinical Neuroscience, UWA
  • Dr Saied Jaradat, Dr Laith Al-Eitan, Jordan University of Science and Technology
  • Dr Jennie Hui, PathWest Laboratory Medicine