Mood & Behavior

Reduces dopamine D2 receptor density in the striatum, affecting reward processing, reinforcement learning, and addiction susceptibility

Promoter variant that modulates dopamine D4 receptor expression in the prefrontal cortex, influencing novelty seeking and cognitive flexibility

Strongest known genetic determinant of dopamine beta-hydroxylase activity, controlling the dopamine-to-norepinephrine ratio

Promoter variant affecting brain serotonin synthesis enzyme; influences emotional reactivity, anxiety, and depression risk

Regulatory variant in serotonin 2A receptor gene affecting SSRI side effects and potentially treatment response

Promoter SNP near 5-HTTLPR that modifies serotonin transporter expression and antidepressant response

Promoter/5' UTR variant in the serotonin 5-HT5A receptor gene affecting receptor expression, linked to schizophrenia susceptibility and executive function

X-linked monoamine oxidase A variant affecting enzyme activity and neurotransmitter breakdown

Co-chaperone of the glucocorticoid receptor that regulates cortisol feedback — the T allele impairs stress recovery and, combined with early adversity, strongly increases risk of PTSD and depression

Most-studied oxytocin receptor variant, influencing empathy, social sensitivity, stress resilience through social buffering, and emotional regulation

Intronic glucocorticoid receptor variant affecting cortisol sensitivity and stress response regulation

Promoter variant in neuropeptide Y that modulates NPY expression under stress, affecting stress resilience, anxiety vulnerability, appetite regulation, and migraine susceptibility

GABA-A receptor alpha-2 subunit variant affecting alcohol response, anxiety, and addiction vulnerability

Affects anandamide levels through altered FAAH enzyme stability, influencing pain sensitivity, stress response, fear extinction, and mood regulation

3'UTR variant in the cannabinoid receptor 1 gene that regulates CB1 expression in the brain and modulates vulnerability to cannabis, alcohol, nicotine, and cocaine dependence, as well as impulsivity and emotional reactivity

Synonymous exon 4 variant in the cannabinoid receptor 1 gene; near an exon splice enhancer, it alters CB1 mRNA stability and modulates vulnerability to cannabis-induced brain changes, PTSD after trauma, and antidepressant treatment response

Intronic variant in the cannabinoid receptor 1 gene that modulates substance dependence vulnerability through a gene-gene interaction with rs806368; the G allele increases risk for drug and alcohol dependence and sits in a completely independent LD block from the rs806368/rs1049353 haplotype

Intronic variant near the CNR1 exon 3 alternative promoter that modulates CB1 receptor mRNA isoform balance; the C (risk) allele is associated with greater hippocampal volume loss in heavy cannabis users, heightened cannabis withdrawal and craving, and participation in a female-specific nicotine dependence haplotype

Nicotinic receptor variant strongly associated with heavy smoking, nicotine dependence, and increased lung cancer risk

Intronic eQTL in CHRNA5 that modulates alpha-5 nicotinic receptor mRNA expression levels, forming an independent risk signal for nicotine dependence and lung cancer distinct from the Asp398Asn coding variant (rs16969968)

CHRNA3 synonymous variant in the nicotinic receptor gene cluster strongly associated with heavy smoking, nicotine dependence, lung cancer, and COPD, with independent effects in non-European populations

CHRNA3 3' UTR variant at 15q25.1 Locus 2 — mechanistically distinct from rs1051730, associated with blunted reward sensitivity to natural stimuli and heightened neural response to cigarette cues

Cis-regulatory enhancer variant at 15q25.1 that drives CHRNA3 and CHRNA5 expression via chromatin looping, independently associated with nicotine dependence and lung cancer risk — particularly informative in non-European populations

Intronic variant near CHRNA3 at 15q25.1 that acts as an eQTL for nicotinic receptor genes and is independently associated with heavy smoking and lung cancer risk

ADH1B variant encoding a ~100x faster alcohol dehydrogenase enzyme, causing rapid acetaldehyde accumulation, the "Asian flush" response, and strong protection against alcoholism — but elevated esophageal cancer risk in carriers who drink

ADH1B*3 variant encoding a superactive alcohol dehydrogenase found almost exclusively in people of African descent, providing strong independent protection against alcoholism by accelerating the conversion of ethanol to acetaldehyde

ADH1C variant defining the fast (ADH1C*1, Arg272) vs slow (ADH1C*2, Gln272) alcohol dehydrogenase isoforms; ADH1C*1 metabolizes ethanol ~2.5x faster, elevating cancer risk in heavy drinkers, while ADH1C*2 slows metabolism and reduces alcohol use disorder risk

L-type calcium channel gene variant affecting mood regulation, emotional processing, and psychiatric disorder risk

Intronic variant in the anti-apoptotic gene BCL2 that affects BCL2 expression levels, intracellular calcium homeostasis, and rate of age-related gray matter loss in key brain regions

Missense variant in the orexin/hypocretin receptor 1 that alters G-protein signaling, increasing susceptibility to migraine, panic disorder, mood dysregulation, and heightened arousal responses