What is post-hypnotic amnesia?
Post-hypnotic amnesia (PHA) is a temporary limitation of recall. It affects content experienced during a hypnosis session. The amnesia is triggered by a deliberate suggestion from the hypnotherapist, and it can be fully reversed through a pre-agreed cancellation signal.
PHA isn't memory deletion. The memories stay stored — only access to them is temporarily blocked.
Does post-hypnotic amnesia really happen?
Yes. Post-hypnotic amnesia is a well-documented phenomenon in hypnosis research. Studies show that PHA occurs reliably above all in highly hypnotisable people. It's brought about deliberately through suggestion and lifted again through suggestion. This reversible character is what clearly distinguishes it from pathological forms of amnesia.
Will I remember everything after a hypnosis session?
In most cases, yes. The majority of people remember everything that happened during a session. Spontaneous memory loss is rare. Some people even report remembering more detail than usual — content that was repressed or stored unconsciously can become more accessible under hypnosis.
Post-hypnotic amnesia only occurs when the therapist deliberately suggests it. It isn't an automatic side effect of hypnosis.
What types of amnesia exist?
There are three main forms of amnesia:
- Anterograde amnesia: new information can no longer be stored after a certain point in time; memories from before that point remain intact.
- Retrograde amnesia: memories from before a particular event are lost, while new information can still be stored.
- Dissociative amnesia: certain experiences or periods of time are blocked from conscious access; the cause is psychological, not neurological.
Functionally, post-hypnotic amnesia belongs to the dissociative category. It differs in that it's brought about deliberately and lifted under control.
How long do post-hypnotic suggestions last?
Post-hypnotic suggestions can last for varying lengths of time. The duration depends on several factors:
- Alignment with your own goals: suggestions that match existing beliefs and wishes tend to last longer.
- Depth of trance: deeper trance favors stronger, more lasting effects.
- Repetition: suggestions reinforced regularly hold for longer.
Some suggestions last days or weeks; others can persist for months or years. Post-hypnotic amnesia itself is time-limited and ends at the latest with the cancellation signal.
Who is especially easy to hypnotise?
Roughly 10 to 15 percent of the population count as highly hypnotisable. Two personality types stand out:
- Highly imaginative people: they have vivid imaginations and can immerse themselves easily in inner imagery.
- People with a dissociative disposition: they can shift between different states of consciousness with ease.
Hypnotisability has nothing to do with intelligence, weak willpower, or gullibility. It's a stable trait that can be measured with standardized scales. Highly hypnotisable people experience post-hypnotic amnesia noticeably more often and more strongly.
Does hypnosis change your personality?
No. Hypnosis can positively influence behaviors, habits, and emotional reactions. The underlying structure of your personality stays unchanged. Hypnotherapy supports change the client is already seeking themselves — it doesn't force a change of personality.
Is post-hypnotic amnesia dangerous?
Post-hypnotic amnesia isn't harmful. It's reversible and controlled — the therapist can restore the memory at any time through the agreed cancellation signal.
Possible short-term after-effects of deep hypnosis include mild tiredness, temporary emotional reactions, or brief difficulty concentrating. These effects fade quickly and aren't a sign of harm.
For certain psychiatric conditions, such as acute psychosis or schizophrenia, hypnosis generally isn't indicated, and post-hypnotic amnesia isn't used in these cases.
Post-hypnotic amnesia in therapy
In hypnotherapy, post-hypnotic amnesia can be used deliberately. It serves to let therapeutic content work on an unconscious level at first, temporarily relieving the conscious mind so change processes can unfold undisturbed.
The amnesia is always a tool in service of the client. It's used transparently and can be lifted at any time.