Why Experiences Vary and Why Intensity Is Not Proof of Benefit

Two questions kept apart

This page answers two separate questions. First, why do experiences differ so much from person to person and session to session? Second, if an experience is more intense, is the outcome better? Research gives a partial answer to the first and a cautious, mixed answer to the second. This is information only. It is not a way to predict, shape or intensify anyone's experience.

Evidence labels used here: established, mixed, insufficient evidence and marketing claim.

Why experiences vary

The National Institute on Drug Abuse (NIDA) says effects of psychedelic and dissociative drugs are difficult to predict and depend on the amount taken, potency, and a person's biology, age, sex, personality, mood, expectations, mindset ("set") and environment ("setting"). It adds that contaminants or combinations with other substances may produce effects not seen with the drug alone. [1]

What controlled data add:

• Pooled analysis of 23 studies. Researchers analyzed 409 psilocybin sessions in 261 healthy volunteers and looked at 24 possible predictors. The amount given was clearly the most important predictor of every response measured. But several non-drug factors also mattered: a high score on the personality trait of "Absorption", being emotionally excitable and active just before, and having had few psychological problems in recent weeks were most associated with pleasant and mystical-type experiences. High emotional excitability, younger age and an experimental setting involving a brain scan (PET) most strongly predicted unpleasant or anxious reactions. [2] Label: established that non-drug factors play a role in this volunteer group.
• A prospective survey. In people planning their own psychedelic experience (654 at the first point, 212 at the last), baseline trait variables had the strongest effect on well-being change. Having a positive "set" and recreation-related intentions were linked to a lower chance of a challenging experience, while "absorption" and higher amounts promoted every aspect of the experience. [3] This was a survey without a control group, so it shows associations only.
• Set, setting and placebo response. A review explains that expectancy, preparation and beliefs shape responses to drugs, and compares the theories of "set and setting" and the placebo response. [4]
• Substance versus amount. A direct comparison of LSD and psilocybin in 28 healthy participants concluded that the alterations of mind they induced did not differ beyond effect duration, and that differences were dose-dependent rather than substance-dependent. [5] We do not give amounts or equivalences here.

Is intensity the same as benefit?

Not on current evidence. Several findings point in different directions, so this is mixed.

• Intensity is not benefit in the lab. In an LSD dose study, good drug effects reached a ceiling at a middle amount, while ego dissolution and anxiety kept rising at a higher amount. [6]
• Quality may matter more than strength. In an analysis of MEQ30 scores, mystical-type scores predicted lasting self-reported change even after accounting for participants' own rating of how intense the drug effects were. [7] A paper arguing that subjective effects are necessary for lasting benefit makes a similar point: certain subjective effects predicted outcomes after intensity was controlled for. The authors present this as a proposal. [8]
• Difficult is not always bad, and not always good. In a survey about worst "bad trip" experiences, degree of difficulty was positively associated with enduring increases in well-being, and difficulty was positively associated with the amount taken. Eleven percent put themselves or others at risk, and 7.6% of those whose experience was over a year earlier sought treatment for enduring symptoms. [9] It was a self-selected retrospective survey.
• Treatment-resistant depression. In 20 patients, both "oceanic boundlessness" and "dread of ego dissolution" ratings related to depression score changes at 5 weeks. [10]
• A systematic review of 12 studies found mostly positive associations between mystical experience and symptom reduction, but small samples and 6 of 12 open-label designs limit confidence. [11]

A strong, dramatic or "life-changing" account is an anecdote, and no source here shows that anecdotes predict who benefits. Online personal stories and marketing for retreats or products are not evidence. Label such claims marketing claim unless supported by a trial.

Why this matters for reading trials

A trial's headline result is the group difference on a clinical scale, not how strong the sessions felt. Expectancy, preparation and beliefs are considered important in shaping responses to drugs. [4] See context and expectancy in psychedelic research, how to read a psychedelic clinical trial and mystical-type experience measures.

Safety note

Because responses are hard to predict, research guidelines rely on screening, preparation, a safe setting and monitoring by trained staff. [12] Those safeguards describe research settings and do not make unsupervised use safe. If you are in distress or in danger, see acute anxiety and distress or call 911 (US) or 988 (US Suicide & Crisis Lifeline).