Nicotine dependence criteria were assessed using the NIMH-DIS revised interview and diagnosed according to the DSM-III-R. Familial smoking characteristics were assessed by subject report.
Nicotine dependence is linked to single nucleotide polymorphisms in the CHRNB4-CHRNA3-CHRNA5 gene cluster encoding the α3β4α5 nicotinic acetylcholine receptor (nAChR).
Nicotine dependence is linked to single nucleotide polymorphisms in the CHRNB4-CHRNA3-CHRNA5 gene cluster encoding the α3β4α5 nicotinic acetylcholine receptor (nAChR).
Nicotine dependence and number of cigarettes smoked per day did not add to the prediction of serum BDNF; however, total number of smoking years was a significant predictor of serum BDNF.
NRXN1 is highly expressed in brain and has been shown recently to be associated with ASD, schizophrenia, cognitive and behavioral abnormalities, and alcohol and nicotine dependence.
CYP2A6 genotype is not associated with nicotine dependence, as defined by the Fagerström Test of Nicotine Dependence, demonstrating that cigarettes smoked per day (CPD) and nicotine dependence have distinct genetic correlates.
Orexin might be a possible target in THC as well as nicotine dependence, taking into account the effect of THC on energy homeostasis in the circuit of reward and motivation and its impact on appetite and body weight.
DBH effects were confirmed [odds ratio (OR) = 0.7, P = 0.04] after controlling for associated clinical variables (MD severity, OR = 3.4, P < 0.001; antisocial personality disorder, OR = 2.2, P < 0.001; alcohol dependence, OR = 1.4, P = 0.05; and nicotine dependence, OR = 1.4, P = 0.06).
NCAM1-TTC12-ANKK1-DRD2 region loci and haplotypes were significantly associated with the motive of Automaticity and, further, Automaticity significantly mediated associations among NCAM1-TTC12-ANKK1-DRD2 cluster variants and nicotine dependence.
DBH was also significantly associated with Automaticity, Craving, and Tolerance; Automaticity and Tolerance also served as mediators of the DBH-ND relationship.
NCAM1-TTC12-ANKK1-DRD2 region variation was significantly associated with the Automaticity subscale and, further, Automaticity significantly mediated associations among NCAM1-TTC12-ANKK1-DRD2 cluster variants and ND.
Catechol-O-methyltransferase (COMT) is one of the major degradative pathways of dopamine and COMT Val/Met polymorphisms are associated with the enzyme activity, which is related to dopamine involvement in the nicotine addiction process.
A cluster of three nicotinic acetylcholine receptor genes on chromosome 15 (CHRNA5/CHRNA3/CHRNB4) has been shown to be associated with nicotine dependence and smoking quantity.