The Evolving Psychedelic Paradigm

APA 2026: Real-World Gaps in GAD Care and Early Safety Data for DT120

How GAD Patients Move Through Treatment

A US insurance-claims analysis, presented at APA 20261 and recently published,2 examined treatment patterns among patients with GAD. In a treatment-patterns sub-cohort of 59,275 patients, switching, discontinuation, and restarting were common. Among patients who discontinued, 42% restarted after a median of 145 days, and 68% of patients who switched therapies had another encounter after 36 days.1 These patterns point to treatment cycling rather than durable control, in line with the known limits of current first-line options.

The Case for a Different Mechanism

That gap in current first-line therapies provides a rationale for testing agents with a different mechanism. DT120 (lysergide) ODT, an orally disintegrating tablet studied in earlier trials as MM120, is a single dose 5-HT2A agonist, the receptor mechanism that underlies the effects of classic psychedelics. In its phase 2b GAD trial, the 100 microgram dose reduced HAM-A scores by a placebo-adjusted 5.0 points at week 4,3 meeting the prespecified primary endpoint, and advanced into phase 3. DT120 has FDA Breakthrough Therapy Designation for GAD, which is a development status and not an approval.

Early Answers on Safety

Two APA 2026 preclinical posters addressed key safety concerns associated with serotonergic psychedelics. Because DT120 is active at the 5-HT2B receptor, which is associated with valvular heart disease, one study chronically dosed rats and found no lysergide-related changes in heart weight or valve tissue and no evidence of ventricular or valvular remodeling at the doses studied.4 A second study assessed abuse and dependence potential. Repeated dosing produced 5-HT2A receptor downregulation consistent with tolerance, and after 25 weeks of weekly dosing the animals showed no evidence of withdrawal or abuse-related behavior.5 These animal findings do not establish human safety, but they speak to the two objections most often raised about the class.

What the APA Data Show Together

The APA data frame two halves of the same story. The real-world analysis shows why better GAD treatments are needed, while the preclinical studies begin to test whether a 5-HT2A agonist can be developed without the long-standing cardiac and dependence concerns associated with this class.  The ongoing phase 3 program will determine whether these early findings translate into clinical benefits and an acceptable safety profile.

References
  1. Louie D, Ferries E, Suponcic S, et al. Treatment patterns for generalized anxiety disorder (GAD): insights from real-world evidence. Poster presented at: American Psychiatric Association Annual Meeting; 2026.
  2. Louie D, Ferries E, Suponcic S, et al. Treatment instability in generalized anxiety disorder (GAD): a U.S. real-world evidence study. CNS Spectrums. Published online June 17, 2026. doi:10.1017/S1092852926101059.
  3. Robison R, Barrow R, Conant C, et al. Single treatment with MM120 (lysergide) in generalized anxiety disorder: a randomized clinical trial. JAMA. 2025;334(15):1358-1372.
  4. Smagin GN, Carter J, Chianini F, Tripp J. DT120 (lysergide tartrate): assessing the potential risk of cardiac valvulopathy after chronic dosing in rats. Poster presented at: American Psychiatric Association Annual Meeting; 2026.
  5. Tripp J, Smagin GN. DT120 (lysergide tartrate): no evidence of abuse potential after chronic dosing in rats. Poster presented at: American Psychiatric Association Annual Meeting; 2026.

The Evolving Psychedelic Paradigm

Generalized Anxiety Disorder: A Persistent Burden and a New Look at Psychedelics

A Common Condition That Carries a High Burden

Generalized anxiety disorder ranks among the most prevalent psychiatric conditions, with a past-year prevalence near 10% of US adults.1 GAD is chronic and recurrent, and the functional toll is heavy, with impairment across work, social, and physical domains, reductions in quality of life comparable to those seen in major depression, and higher medical costs than in patients without the disorder.2 Comorbidity magnifies the burden, with mood and other anxiety disorders frequently accompanying the diagnosis.

Standard Treatments With Incomplete Results

SSRIs and SNRIs remain the foundation of pharmacologic care, but their efficacy is less than ideal. In a network meta-analysis of double-blind randomized trials, first-line agents such as duloxetine, escitalopram, paroxetine, and venlafaxine roughly doubled the odds of remission compared with placebo (odds ratios of about 1.7 to 2.3), 3 yet roughly half of patients have an inadequate response to first-line treatment.4 Therapeutic options have also stalled, with no new pharmacotherapy approved for GAD in the US market since 2007.5

What Real-World Prescribing Reveals

A 2026 real-world analysis of US insurance claims covering 259,158 newly diagnosed and 1,018,288 established patients with GAD underscores the gap.6 SSRIs were the most common treatment class (45% of newly diagnosed and 51% of established patients), followed by benzodiazepines and other antidepressants, with benzodiazepine use markedly higher in established disease (33% versus 22%). Approximately 25% of newly diagnosed patients had no pharmacotherapy claim in the 12 months after diagnosis.

Where Standard Care Falls Short

Standard pharmacotherapy helps many patients but leaves many others symptomatic, and the absence of a mechanistically new approval for nearly two decades limits what clinicians can offer those who do not respond. That gap is pushing the field toward a markedly different approach. Serotonergic psychedelics, long outside mainstream psychiatry, are being formally evaluated in generalized anxiety disorder, including a lysergide-based agent tested in a recent randomized, placebo-controlled trial.5 How these compounds work, and whether their benefits prove durable, is now a question of keen interest to researchers, clinicians, and patients alike.

Bar chart of treatment patterns in GAD: SSRIs, benzodiazepines, other antidepressants

References
  1. Ringeisen H, Edlund M, Guyer H, et al. Mental and Substance Use Disorders Prevalence Study (MDPS): findings report. RTI International; 2023.
  2. Revicki DA, Travers K, Wyrwich KW, et al. Humanistic and economic burden of generalized anxiety disorder in North America and Europe. J Affect Disord. 2012;140(2):103-112.
  3. Kong W, Deng H, Wan J, et al. Comparative remission rates and tolerability of drugs for generalised anxiety disorder: a systematic review and network meta-analysis of double-blind randomized controlled trials. Front Pharmacol. 2020;11:580858.
  4. Ansara ED. Management of treatment-resistant generalized anxiety disorder. Ment Health Clin. 2020;10(6):326-334.
  5. Robison R, Barrow R, Conant C, et al. Single treatment with MM120 (lysergide) in generalized anxiety disorder: a randomized clinical trial. . 2025;334(15):1358-1372.
  6. Louie D, Ferries E, Suponcic S, et al. Treatment patterns among newly diagnosed patients with generalized anxiety disorder and patients with established GAD: insights from real-world evidence. Poster presented at: ASCP Annual Meeting; 2026.

The Evolving Psychedelic Paradigm

Beyond SSRIs: Why the Next Advance in GAD May Not Target Monoamines

The Remission Gap in GAD

Serotonin reuptake inhibitors and serotonin-norepinephrine reuptake inhibitors remain the backbone of long-term GAD pharmacotherapy, and they help many patients. Full remission, though, is the exception rather than the rule. In a network meta-analysis of randomized GAD trials, active agents differed from placebo on remission, defined as a HAM-A score of 7 or less, but only by modest odds ratios; across the pooled trials, remission rates on active drugs clustered well below half, leaving a large number of treated patients with residual symptoms.1 Benefit also tends to accrue over weeks, and patients who do not respond often move through dose increases, switches, and augmentation, each carrying its own tolerability cost.2

Psychedelics as Mechanistic Diversity

What these first-line drugs share is their target. Whether a molecule blocks the serotonin transporter, the norepinephrine transporter, or both, its proximate action stays inside the monoamine system. These drugs are not inert at the level of plasticity: several antidepressants bind the BDNF receptor TrkB and engage neuroplasticity, a mechanism that may help explain both their benefit and their slow onset.3 The newer interest is in agents that engage plasticity more directly and quickly. Preclinical work characterizes classic psychedelics as psychoplastogens, compounds that produce rapid, sustained structural plasticity, including greater dendritic complexity, after a single exposure, an effect that requires activation of 5-HT2A receptors inside the cell rather than only at its surface.4

Translating Plasticity to the Clinic

That mechanistic premise has begun to meet clinical data in anxiety. In a phase 2b dose-finding trial, a single 100 microgram dose of DT120 (lysergide) ODT, a 5-HT2A agonist, lowered HAM-A scores by a placebo-adjusted 5.0 points at week 4, the study’s prespecified primary outcome.5 The compound is investigational, but it is the first placebo-controlled signal that one administration of a non-monoaminergic agent can shift anxiety symptoms in GAD.5

Beyond the Monoamine Paradigm

None of this means the monoamine drugs have failed. They remain first-line, and for many patients they work well. What has changed is that psychiatry now has more than one mechanistic hypothesis to test in anxiety, something it has lacked for a generation. Whether plasticity-based agents produce durable benefit in practice is the question the current trials are investigating.

Comparison of Two Mechanisms for Treating Anxiety

First-line monoamine drugs
SSRIs and SNRIs
Classic psychedelics
5-HT2A agonists, e.g., DT120 (lysergide) ODT
Molecular target Serotonin and norepinephrine transporters at the cell membrane 5-HT2A receptors, including intracellular receptors
Mechanism of action Block monoamine reuptake; also engage neuroplasticity via TrkB, but gradually Agonize 5-HT2A receptors; drive rapid structural plasticity after a single dose

Both drug classes engage neuroplasticity; they differ in route and speed, not in whether plasticity occurs. Sources: Casarotto et al., Cell 2021; Vargas et al., Science 2023; and Robison et al., JAMA 2025.

References
  1. Kong W, Deng H, Wan J, et al. Comparative remission rates and tolerability of drugs for generalised anxiety disorder: a systematic review and network meta-analysis. Front Pharmacol. 2020;11:580858.
  2. Melaragno AJ. Pharmacotherapy for anxiety disorders: from first-line options to treatment resistance. Focus (Am Psychiatr Publ). 2021. PMCID: PMC8475920.
  3. Casarotto PC, Girych M, Fred SM, et al. Antidepressant drugs act by directly binding to TRKB neurotrophin receptors. Cell. 2021;184(5):1299-1313. doi:10.1016/j.cell.2021.01.034.
  4. Vargas MV, Dunlap LE, Dong C, et al. Psychedelics promote neuroplasticity through activation of intracellular 5-HT2A receptors. Science. 2023;379(6633):700-706.
  5. Robison R, Barrow R, Conant C, et al. Single treatment with MM120 (lysergide) in generalized anxiety disorder: a randomized clinical trial. JAMA. 2025;334(15):1358-1372.

The Evolving Psychedelic Paradigm

Psychedelics Are Advancing in GAD, but None Are Yet Approved

What the “Pipeline” Label Hides

The phrase “psychedelic pipeline” groups compounds at very different stages of development, and important distinctions get lost in the shared label. What separates these agents is where each one stands. Some are approved, while others remain investigational. The supporting evidence also varies, ranging from published trials to early company press releases. For GAD, the evidence has grown quickly, but is still limited to early-phase trials.

Two Controlled Signals in Anxiety

GAD now has two positive controlled trials on different compounds. In a phase 2b dose-finding study, a single 100 µg dose of DT120 (lysergide) ODT, the compound published as MM120, produced a placebo-adjusted reduction of 5.0 points on the HAM-A at week 4, the prespecified primary endpoint, exceeding the trial’s 2.5-point threshold for clinical importance.1 Separately, in a randomized, placebo-controlled phase 2 trial, psilocybin-assisted therapy delivered across two dosing sessions produced a statistically significant reduction in HAM-A scores versus placebo, according to company topline results that have not been peer reviewed.2 Both agents remain investigational and are administered under supervision because of acute perceptual effects.

The One Approved Option Treats Depression, Not Anxiety

The one approved agent in this group is indicated for depression, not anxiety. Esketamine, an NMDA-receptor antagonist rather than a classic serotonergic psychedelic, carries a 2025 monotherapy indication for treatment-resistant depression, granted after it separated from placebo within 24 hours and held through day 28 in a randomized trial.3 No psychedelic, classic or otherwise, is approved for GAD.

Reading by Stage, Not by Label

Stage of evidence is the key distinction that matters most. Study results for GAD currently come from phase 2 trials. The lysergide program’s first phase 3 study recently reported positive topline results in depression.4 Its two phase 3 trials in GAD, Voyage (NCT06741228) and Panorama (NCT06809595), have not yet reported results, though topline data are expected in the third quarter of 2026. Enthusiasm has outrun evidence in this field before. In 2024 the FDA declined to approve MDMA-assisted therapy for post-traumatic stress disorder, citing unresolved questions about study conduct and durability of effect.5 For GAD, the pipeline is real and growing, but its controlled signals are early, and no psychedelic is yet approved for anxiety.

Timeline of psychedelic agents' development stages for GAD treatment

References
  1. Robison R, Barrow R, Conant C, et al. Single treatment with MM120 (lysergide) in generalized anxiety disorder: a randomized clinical trial. JAMA. 2025;334(15):1358-1372.
  2. Incannex Healthcare. Incannex reports positive results from phase 2 clinical trial of PSX-001 (Psi-GAD) for generalised anxiety disorder [press release]. August 26, 2025.
  3. Janik A, Qiu X, Lane R, et al. Janik A, Qiu X, Lane R, et al. Esketamine monotherapy in adults with treatment-resistant depression: a randomized clinical trial. JAMA Psychiatry. 2025;82(9):877-887.
  4. Definium Therapeutics. Positive topline results from the phase 3 Emerge study of DT120 orally disintegrating tablet (ODT) in major depressive disorder [press release]. June 22, 2026.
  5. US Food and Drug Administration. Complete response letter, NDA 215455 (midomafetamine capsules). August 8, 2024.