Decreased mental time travel to the past correlates with default-mode network disintegration under lysergic acid diethylamide
Jana Speth, Clemens Speth, Mendel Kaelen, Astrid M Schloerscheidt, Amanda Feilding, David Nutt, Robin Carhart-Harris
Journal of Psychopharmacology 2016 DOI: 10.1177/0269881116628430 (opens in new tab)
Study at a glance
AI-extracted from the abstract| Characteristics | Randomized controlled crossover trial Placebo-controlled Peer reviewed |
|---|---|
| Sample size | 20 |
| Population | Healthy volunteers |
| Intervention | LSD |
| Dose | 75 μg |
| Duration | Approximately 2.5 h post-administration |
| Topics | Default mode network LSD |
| Keywords | Mental health Cognitive health Emotional well-being Brain research Neurobiology Cognitive neuroscience Brain function Rumination Overthinking Past-dwelling Intrusive thoughts Obsessive thinking Repetitive thought Drug therapy Medication Therapeutics Psychopharmacology Drug research |
| Citations | 119 |
| Post-publication review | 1 comment on PubPeer (opens in new tab) · last active September 2016 |
| Key findings | LSD significantly reduced mental time travel to the past, and this effect correlated with decreased default-mode network connectivity. |
Abstract
This paper reports on the effects of LSD on mental time travel during spontaneous mentation. Twenty healthy volunteers participated in a placebo-controlled crossover study, incorporating intravenous administration of LSD (75 μg) and placebo (saline) prior to functional magnetic resonance imaging (fMRI). Six independent, blind judges analysed mentation reports acquired during structured interviews performed shortly after the functional magnetic resonance imaging (fMRI) scans (approximately 2.5 h post-administration). Within each report, specific linguistic references to mental spaces for the past, present and future were identified. Results revealed significantly fewer mental spaces for the past under LSD and this effect correlated with the general intensity of the drug’s subjective effects. No differences in the number of mental spaces for the present or future were observed. Consistent with the previously proposed role of the default-mode network (DMN) in autobiographical memory recollection and ruminative thought, decreased resting-state functional connectivity (RSFC) within the DMN correlated with decreased mental time travel to the past. These results are discussed in relation to potential therapeutic applications of LSD and related psychedelics, e.g. in the treatment of depression, for which excessive reflection on one’s past, likely mediated by DMN functioning, is symptomatic