W1 T3; Risk factors for addiction
Genes
Last 20 years have been progress in identifying specific gene variants
Articles are misleading, as there is no one gene for addiction or dependence
Complex behaviours are influenced by many genes, with individual risk low
(heterogeneity)
A number of genes have been associated below with alcohol and nicotine
dependence but all have very low risk
For cannabis dependence, a number of candidates proposed
So far, little replication of results; meta analysis of cannabis gwas and gene based
association tests found no significant SNP (Agrawal et al, 2011)
Another gwas of cannabis dep with dsm diagnosis found no snp (Agrawal, 2014)
Addiction is multi stage
Most studies compare drug users and non drug users, which confounds early stage
of dependence; could have different genetic influence at different stages e.g.
personality traits for nonconformity
Later stages could be influenced by genes for drug metabolism
Studies may need to look at just one stage such as initiation to identify variants
Genes
Last 20 years have been progress in identifying specific gene variants
Articles are misleading, as there is no one gene for addiction or dependence
Complex behaviours are influenced by many genes, with individual risk low
(heterogeneity)
A number of genes have been associated below with alcohol and nicotine
dependence but all have very low risk
For cannabis dependence, a number of candidates proposed
So far, little replication of results; meta analysis of cannabis gwas and gene based
association tests found no significant SNP (Agrawal et al, 2011)
Another gwas of cannabis dep with dsm diagnosis found no snp (Agrawal, 2014)
Addiction is multi stage
Most studies compare drug users and non drug users, which confounds early stage
of dependence; could have different genetic influence at different stages e.g.
personality traits for nonconformity
Later stages could be influenced by genes for drug metabolism
Studies may need to look at just one stage such as initiation to identify variants
