People with a fear of vomiting often describe a particular memory in unusual detail. The room, the smell, who was there, what happened afterwards. Decades later it can be recalled as though it happened last week.
Veale and colleagues at King's College London tested whether that impression holds up. They compared 94 people with a specific phobia of vomiting against 90 community volunteers matched for age and sex, asking both groups to record their lifetime memories of vomiting, their own and other people's, and to rate how distressing each memory was.
Several differences emerged. The phobia group recalled their first memory of vomiting at a younger age, and rated their memories as far more distressing. They were much more likely to remember other people vomiting: 87% could recall at least one such episode, against 24% of the comparison group. They also linked those memories to a wider range of consequences, including embarrassment in front of others, illness, and events in their lives that had nothing to do with being sick.
After the phobia had taken hold, the pattern reversed for their own vomiting. They recalled fewer episodes of it than the comparison group, which fits with years of successful avoidance, while recalling more episodes of others being sick, which fits with watching closely for signs of it.
The picture is of memories that have lost their place in time and are reactivated whenever something resembles them. That is a treatable pattern, and it is one that therapy can work with directly.
The question
Vomiting is close to a universal human experience, yet only a small number of people develop a phobia of it. Very little is known about why. Associative accounts suggest phobias grow out of a learning experience, either a frightening event or watching someone else be frightened. Non-associative accounts suggest some fears arise without any such event. Veale and colleagues set out to examine what people with a specific phobia of vomiting, abbreviated SPOV, actually remember.
Who took part
Ninety-four people with SPOV were recruited, 88 women and 6 men. About a quarter came from a clinical setting and the rest from websites and internet support groups. Diagnosis was confirmed with a structured clinical interview conducted in person or by telephone. The comparison group of 90 people, 87 women and 3 men, came from a community research database at the Institute of Psychiatry and had no history of psychiatric disorder. Mean age was 32.3 years in the phobia group and 32.5 in the comparison group, with no significant difference in age or sex. Mean age of onset of the phobia was 15.7 years.
Participants recorded up to ten episodes of their own vomiting and up to ten of others vomiting, gave the age at which each happened, and rated how distressing the memory was on a 0 to 10 scale. Each person with SPOV was individually matched to a comparison participant within two years of age, which allowed memories to be split into those formed before and after the age at which the phobia became a problem.
What was found
Every person in the SPOV group could recall at least one memory of their own vomiting, compared with 93.3% of the comparison group. The SPOV group recalled their first episode at a significantly younger age and rated the memories as significantly more distressing. Across a lifetime they recalled fewer episodes of their own vomiting than the comparison group.
Once age of onset was accounted for, the two groups did not differ in the number of memories of their own vomiting formed before the phobia began. Afterwards the SPOV group recalled fewer, with a mean of 1.6 episodes against 3.3 in the comparison group. Expressed over time, that is roughly one fewer episode every 9.8 years.
Memories of other people vomiting ran the other way. At least one was recalled by 87.4% of the SPOV group and only 23.6% of the comparison group, a large and statistically significant gap. The SPOV group recalled these memories from an earlier age, recalled more of them both before and after onset, and rated them as more distressing. After onset they averaged 2.6 such memories against 0.4 in the comparison group.
The SPOV group also reported significantly more associations attached to their memories, covering interpersonal consequences, health or emotional consequences, and unrelated life events happening at the same time.
How the authors read it
Two things follow. First, the fewer memories of their own vomiting after onset are consistent with avoidance and vigilance having genuinely reduced how often they were sick, which would reinforce those behaviours. Second, the emotional intensity and the breadth of associations point to memories that have lost their time perspective and context, and that are reactivated by present-day cues rather than recalled as past events. That is the same quality seen in intrusive memories in other conditions, and it suggests memory-focused work has a place alongside exposure.
Limits
Both groups were reporting retrospectively, so memory bias affects the data in both directions. Recall was capped at ten episodes, which 5.3% of the SPOV group and 27.8% of the comparison group reached for their own vomiting, so the true lifetime difference may be understated. Most participants were recruited online, and the design was exploratory rather than confirmatory.
If vivid memories of being sick keep returning as though they were happening now, that experience is recognised in the research and can be treated.