Serotonergic neurotransmission in emotional processing: New evidence from long-term recreational poly-drug ecstasy use
Helle Ruff Laursen, Susanne Henningsson, Julian Macoveanu, Terry L. Jernigan, Hartwig R. Siebner, Klaus K. Holst, Arnold Skimminge, Gitte M. Knudsen, Thomas Z. Ramsøy, David Erritzøe
Journal of Psychopharmacology September 6, 2016 DOI: 10.1177/0269881116662633 via OpenAlex
Summary
Prolonged recreational use of MDMA (ecstasy) alters serotonin neurotransmission, similar to a depleted state. In this fMRI study, 14 ecstasy users and 12 non-users viewed faces expressing anger, disgust, fear, sadness, or no emotion while their amygdala activity was measured. Serotonin transporter binding, assessed via PET, correlated negatively with amygdala activity in users. Greater lifetime ecstasy intake was associated with increased amygdala activity during angry face processing, while longer time since last use showed a trend toward decreased activity during angry and sad face processing. The results indicate dose-dependent effects of long-term serotonin depletion on emotional face processing.
Study at a glance
| Characteristics | Observational cohort Peer reviewed |
|---|---|
| Sample size | 26 |
| Population | Recreational ecstasy users and non-using controls |
| Topics | MDMA Serotonin |
| Keywords | Hallucinogen Recreational drug |
| Citations | 8 |
| Key finding | Lifetime ecstasy intake is associated with increased amygdala activity during angry face processing, while time since last use shows a trend toward decreased activity. |
Abstract
The brain’s serotonergic system plays a crucial role in the processing of emotional stimuli, and several studies have shown that a reduced serotonergic neurotransmission is associated with an increase in amygdala activity during emotional face processing. Prolonged recreational use of ecstasy (3,4-methylene-dioxymethamphetamine [MDMA]) induces alterations in serotonergic neurotransmission that are comparable to those observed in a depleted state. In this functional magnetic resonance imaging (fMRI) study, we investigated the responsiveness of the amygdala to emotional face stimuli in recreational ecstasy users as a model of long-term serotonin depletion. Fourteen ecstasy users and 12 non-using controls underwent fMRI to measure the regional neural activity elicited in the amygdala by male or female faces expressing anger, disgust, fear, sadness, or no emotion. During fMRI, participants made a sex judgement on each face stimulus. Positron emission tomography with 11 C-DASB was additionally performed to assess serotonin transporter (SERT) binding in the brain. In the ecstasy users, SERT binding correlated negatively with amygdala activity, and accumulated lifetime intake of ecstasy tablets was associated with an increase in amygdala activity during angry face processing. Conversely, time since the last ecstasy intake was associated with a trend toward a decrease in amygdala activity during angry and sad face processing. These results indicate that the effects of long-term serotonin depletion resulting from ecstasy use are dose-dependent, affecting the functional neural basis of emotional face processing.