The authors examined the difference between two (theoretical) subtypes of OCD symptoms. Based on the earlier work of Lee and Kwon, obsessions can be divided into autogenous and reactive.
Autogenous: occur without identifiable or likely stimuli; repetitive; disturbing;
Examples: "sexual, aggressive, or immoral thoughts, images, or impulses." The sudden obsession to rape; or seeing a red shirt, which signifies raping.
Coping strategy: suppress these thoughts
Reactive: caused by identifiable external stimuli, including thoughts of contamination, asymmetry, loss; are realistic;
Coping strategy:reduce anxiety (e.g. wash hands.)
They found some interesting differences:
Autogenous obsessives were more likely to be male, and older (34) and have older ages of onset (27);
Reactive obsessives were more likely female (60/40), younger (27) and younger age of onset (19).
No difference in either group in education or marital status; nor were there any major psychiatric comorbidities.
But autogenous obsessives rarely (1%) dissociated; reactives did dissociate (10%).
A few points. That aggressive/sexual thoughts go with males is no surprise. But that they are found in the older people is interesting. If you can see how primitive thinking occurs in reactive OCD, it makes sense they would get their symptoms at a younger age. It is known that cleaning and checking obsessions are associated with an earlier age of onset.
The prevalence of dissociation in reactive patients- or the absence of it in autogenous patients-- had already been suspected. Checking and symmetry symptoms (associated here with reactive type) had already been found to be more commonly associated with dissociation. (Personal diversion: my own clinical experience with pedophiles supports this-- that those with sexual obsessions are fully conscious of them; obsess over them, are familiar with every nuance. They know to molecular detail what the child looks like, how it moves; and are totally aware of their own behavior at every step of the molestation, even when they pretend a quasi-dissociative experience as a defense. They wouldn't dissociate during the acts because, in effect, it defeats the purpose of committing the act.)
Additionally, in other studies, Lee and partners (Telch, Kwon, etc) found that autogenous obsessions were more associated with schizotypal personality than to other OCD symptoms themselves (while reactive obsessions had no association with schizotypal.) 1 The authors use this finding to support the idea that autogenous obsessions represent cognitive issues, while reactive represent behavioral ones; autogenous obsessives obsess; reactive obsessives are compulsives. This is further supported another study finding that on Rorshach, autogenous obsessives, like schizophrenics, have severe thought disorder, while reactive obsessives do not.2 The belief that merely thinking a thought could make it true (formally called the likelihood bias of though-action fusion) sounds like the magical thinking in schizotypal, and in fact TAF is seen in schizotypals 4 1. It would be interesting if it could be investigated in autogenous obsessives versus reactive obsessives separately, the hypothesis being that autogenous obsessives display likelihood TAF, while reactives do not.
Clinically, it may be fair to say that people with autogenous type obsessions share schizotypal features, and cognitive/perceptual distortions, while reactive obsessions go with OCPD features and compulsive behaviors. So, do antipsychotics help autogenous obsessives (and not (or better than) reactive obsessives?)
In line with this, there is some evidence that schizophrenics and OCDs share some neurodevelopmental pathology. For example, using fractal dimension and CSF volume, one could accurately categorize schizophrenics or OCD patients, vs controls, with 90% accuracy.3 It would be interesting to see if these obsessives, based on brain pathology alone, could be distinguished between autogenous and reactive types. I suspect the answer will be yes.