Serotonin 6 receptor gene is associated with methamphetamine-induced psychosis in a Japanese population.
BACKGROUND
Altered serotonergic neural transmission is hypothesized to be a susceptibility factor for psychotic disorders such as schizophrenia. The serotonin 6 (5-HT6) receptor is therapeutically targeted by several second generation antipsychotics, such as clozapine and olanzapine, and d-amphetamine-induced hyperactivity in rats is corrected with the use of a selective 5-HT6 receptor antagonist. In addition, the disrupted prepulse inhibition induced by d-amphetamine or phencyclidine was restored by 5-HT6 receptor antagonist in an animal study using rats. These animal models were considered to reflect the positive symptoms of schizophrenia, and the above evidence suggests that altered 5-HT6 receptors are involved in the pathophysiology of psychotic disorders. The symptoms of methamphetamine (METH)-induced psychosis are similar to those of paranoid type schizophrenia. Therefore, we conducted an analysis of the association of the 5-HT6 gene (HTR6) with METH-induced psychosis.


METHODS
Using five tagging SNPs (rs6693503, rs1805054, rs4912138, rs3790757 and rs9659997), we conducted a genetic association analysis of case-control samples (197 METH-induced psychosis patients and 337 controls) in the Japanese population. The age and sex of the control subjects did not differ from those of the methamphetamine dependence patients.


RESULTS
rs6693503 was associated with METH-induced psychosis patients in the allele/genotype-wise analysis. Moreover, this association remained significant after Bonferroni correction. In the haplotype-wise analysis, we detected an association between two markers (rs6693503 and rs1805054) and three markers (rs6693503, rs1805054 and rs4912138) in HTR6 and METH-induced psychosis patients, respectively.


CONCLUSIONS
HTR6 may play an important role in the pathophysiology of METH-induced psychosis in the Japanese population.
Kishi
Taro
T
Department of Psychiatry, Fujita Health University School of Medicine, Toyoake, Aichi, Japan. tarok@fujita-hu.ac.jp
Fukuo
Yasuhisa
Y
Okochi
Tomo
T
Kitajima
Tsuyoshi
T
Kawashima
Kunihiro
K
Naitoh
Hiroshi
H
Ujike
Hiroshi
H
Inada
Toshiya
T
Yamada
Mitsuhiko
M
Uchimura
Naohisa
N
Sora
Ichiro
I
Iyo
Masaomi
M
Ozaki
Norio
N
Iwata
Nakao
N
D019969:Amphetamine-Related Disorders / Q000235:genetics*; D044466:Asian People / Q000235:genetics; D000697:Central Nervous System Stimulants / Q000009:adverse effects* / Q000494:pharmacology; D005260:Female; D055106:Genome-Wide Association Study; D005838:Genotype; D006239:Haplotypes; D006801:Humans; D008297:Male; D008694:Methamphetamine / Q000009:adverse effects*; D020641:Polymorphism, Single Nucleotide; D011605:Psychoses, Substance-Induced / Q000235:genetics* / Q000503:physiopathology; D011985:Receptors, Serotonin / Q000235:genetics*
D000697:Central Nervous System Stimulants; D011985:Receptors, Serotonin; C097216:serotonin 6 receptor; D008694:Methamphetamine