As psychedelic treatments move deeper into psychiatric research, investigators are increasingly asking what happens after the immediate drug experience has ended. New interventional psychiatry research suggests that some compounds may be associated with changes in cognitive functioning that persist into the days or longer periods following administration.
A new systematic review published in Neuroscience & Biobehavioral Reviews examined clinical and preclinical research involving psilocybin, LSD, DMT, MDMA, and ketamine. Rather than focusing on cognition during acute intoxication, the researchers evaluated changes occurring at least one day after administration, providing a broader view of how these treatments may influence executive function, attention, and decision-making.
Why Cognition Matters In Psychedelic Treatment
Many psychiatric disorders involve more than mood symptoms. Depression, anxiety disorders, obsessive-compulsive disorder, and substance use disorders can involve persistent patterns of rigid thinking, attentional biases, repetitive behaviors, and difficulty adapting to changing circumstances.
Executive functions such as working memory, inhibitory control, and cognitive flexibility help people regulate behavior and respond effectively to new information. Impairment in these abilities may also interfere with psychotherapy, treatment adherence, and the ability to replace maladaptive patterns with healthier ones.
This raises an important question for psychedelic-assisted therapy: could treatment influence not only psychiatric symptoms, but also some of the cognitive processes involved in recovery?
Psychedelics And Cognitive Function Vary By Compound
The review included 67 studies, comprising 47 clinical and 20 preclinical reports. The results did not support a single cognitive effect shared across all psychedelic or psychedelic-adjacent compounds.
Psilocybin produced the most consistent evidence of improvement, particularly in cognitive flexibility and attention. Ketamine was also associated with improvements across several cognitive domains, although findings varied considerably between studies.
LSD and DMT did not demonstrate consistent post-acute cognitive changes. MDMA, meanwhile, was associated with temporary cognitive impairments that generally resolved within days.
These differences are important because they challenge the assumption that compounds commonly grouped within psychedelic medicine necessarily produce comparable longer-term cognitive effects.
Clinical Populations May Respond Differently
Another notable finding was that cognitive improvements appeared more frequently in people with psychiatric conditions than in healthy participants.
The authors suggest this could represent restoration of impaired cognitive functioning rather than enhancement beyond normal cognitive performance. In other words, a treatment might help normalize a cognitive process disrupted by illness without necessarily making cognition better than normal.
That distinction may become increasingly relevant as researchers investigate cognitive outcomes as potential components of therapeutic response.
Neuroplasticity Offers A Possible Explanation
One mechanism that could help explain persistent cognitive changes is neuroplasticity, the brain’s capacity to modify neural connections in response to experience.
Preclinical research has shown changes in synaptic and dendritic growth following psychedelic administration, while human and animal studies have identified changes involving brain-derived neurotrophic factor, mTOR signaling, and functional connectivity in circuits associated with executive processing.
Related research has proposed neuroplasticity as a convergent downstream mechanism linking ketamine and classical psychedelics. Although the compounds act through different primary receptor systems, both may ultimately promote synaptic, structural, and functional changes in brain networks relevant to psychiatric illness.
This does not establish that neuroplasticity directly causes the cognitive findings identified in the new review. It does, however, provide a biological framework for investigating why certain changes might continue after the immediate pharmacological experience has passed.
A Review Focused On The Post-Acute Window
The timing of the analysis makes this review particularly relevant. Previous research has often concentrated on cognition during intoxication or examined longer-term outcomes without specifically capturing the days immediately following treatment.
The researchers defined the post-acute period as beginning at least one day after dosing. This allowed them to examine the period sometimes described as the psychedelic “afterglow,” when acute drug effects have subsided but biological and psychological changes may continue.
What The Evidence Can And Cannot Tell Us
The findings remain preliminary. The included studies differed substantially in populations, interventions, cognitive tests, and research methods. The authors also identified concerns involving selective outcome reporting, missing data, and inadequate methodological detail.
Accordingly, the review does not establish that psychedelic treatment reliably improves cognition. Instead, it identifies a signal worth testing with larger controlled studies and standardized cognitive measures.
For interventional psychiatry, this distinction matters. Future trials may increasingly evaluate cognitive flexibility, attention, and executive functioning alongside conventional symptom scales. Doing so could clarify whether cognitive change represents an independent treatment effect, a marker of clinical recovery, or part of the mechanism through which certain interventions support longer-lasting improvement.
The emerging picture is not that psychedelics uniformly enhance cognition. It is more precise: different compounds may produce different post-acute cognitive profiles, with psilocybin and ketamine currently showing the strongest preliminary signals. Understanding those differences could help researchers define not only whether these treatments work, but also what changes after treatment and why.
Citations
- Kelly C, Cooley BJ, Zeng L, et al. “Subacute and long-term changes in cognitive functioning after administration of classic psychedelics, MDMA and ketamine: A systematic review of clinical and preclinical evidence.” Neuroscience & Biobehavioral Reviews. 2026. DOI: 10.1016/j.neubiorev.2026.106911. ScienceDirect Article
- Aleksandrova LR, Phillips AG. “Neuroplasticity as a convergent mechanism of ketamine and classical psychedelics.” Trends in Pharmacological Sciences. 2021;42(11):929-942. DOI: 10.1016/j.tips.2021.08.003. PubMed Article
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