Dopamine and Alcohol: A Review of in vivo PET and SPECT Studies

Abstract

<b><i>Background:</i></b> Alcohol-associated alterations of the dopaminergic (DA) system have been investigated via functional single-photon emission tomography (SPECT) positron emission tomography (PET) and imaging methods over many years, investigating presynaptic or postsynaptic markers, such as DA receptor and DA transporter availability, both with and without challenge. This review summarizes SPECT and PET studies on different levels of alcohol consumption to support the dimensional view of alcohol use disorder (AUD), ranging from acute consumption in social drinkers, individuals at high risk to patients with severe AUD and their association with blunted DA neurotransmission. Additionally, confounding factors of PET and SPECT studies of the DA system were discussed. <b><i>Summary:</i></b> The included studies provided strong evidence that acute alcohol administration in social drinkers is followed by a DA release, particularly in the ventral striatum. In participants with AUD, DA release appears to be impaired as administration of a psychostimulant is followed by a blunted striatal DA. Furthermore, in recently detoxified participants with AUD, in vivo dopamine D2 and D3 receptor availability appears to be reduced, which may be a predisposing factor or the result of a neuroadaptive process influencing drug-induced DA release. DA transporter availability is reduced in AUD, whereas findings with respect to DA synthesis capacity are controversial. <b><i>Key Messages:</i></b> The DA system seems to be differently impaired during the development and persistence of AUD. In total, challenge studies (acute alcohol or psychostimulant administration) seem to be more consistent in their findings and might be less prone to the effects of confounders. Long-term studies with larger samples are required to better evaluate the alterations during chronic consumption and prolonged abstinence.

Correlation of striatal dopamine D2/3 receptor availability with GABA level in the anterior cingulate cortex in healthy controls but not in alcohol‐dependent subjects and individuals at high risk: A multimodal magnetic resonance spectroscopy and positron emission tomography study

“…We were able to expand our previous finding of reduced dopamine D2/3 receptor availability (BP) in AD patients compared to LR and HR controls 21 using the AS, LS and SMS that were found to be implicated in earlier studies 44 . More precisely, we found reduced BP of AD patients in the dorsal striatum, which is in line with a recent meta‐analysis and review 12,13 . Interestingly, according to our previous study, we did not find an impairment of dopamine D2/3 availability in the ventral striatum, which is in contrast to some previous studies 10 .…”

“…Striatal dopamine (DA) is released during acute alcohol intake, which leads to the rewarding effects of alcohol and may reinforce alcohol use 9 . Chronic alcohol use has been associated with reduced dopamine D2/3 receptor sensitivity and availability in the striatum, 10,11 which has been confirmed in a recent meta‐analysis and a review 12,13 …”

“… 9 Chronic alcohol use has been associated with reduced dopamine D2/3 receptor sensitivity and availability in the striatum, 10 , 11 which has been confirmed in a recent meta‐analysis and a review. 12 , 13 …”

“…9 Chronic alcohol use has been associated with reduced dopamine D2/3 receptor sensitivity and availability in the striatum, 10,11 which has been confirmed in a recent meta-analysis and a review. 12,13 Moreover, the interplay of GABA and the major excitatory transmitter glutamate (Glu) and their balance is crucial for inhibitory control. GABA and Glu interact with the dopaminergic system, and thus both are crucial for reward and motivation.…”

Intra-Striatal Dopaminergic Inter-Subject Covariance in Social Drinkers and Nontreatment-Seeking Alcohol Use Disorder Participants

“…After establishing that DAergic striatal covariance networks possessed organizational features, we investigated potential alterations in AUD, as substance use disorders are believed to disrupt DAergic system function (Koob and Volkow 2010). Our analyses showed that the covariance structure of the AUD group network is indeed altered, showing less organization and lower network degree, density, and strength (Figure 2), supporting previous literature that alcohol dependence disrupts dopaminergic function in the striatum (Spitta et al 2023), while providing novel insight into the inter-regional relationships of DAergic function. We identified three edges in which covariance significantly differed between AUD and CON: ipsilateral left hemisphere nucleus accumbens shell and anterior caudate, and contralateral left accumbens core and right hemisphere accumbens shell and core (Figure 2A).…”