It has been estimated that up to 10 percent of patients treated with clozapine develop obsessive-compulsive symptoms. And I’m in the 10 percent category. I’m constantly washing my hands and face/eyes.
There are many studies pointing clozapine with OCD.
http://schizophreniabulletin.oxfordjournals.org/content/24/3/381.full.pdf
Still, multiple case reports describe this phenomenon. It has been hypothesized that clozapine’s antiserotonergic effects are responsible for the emergence of obsessive-compulsive symptoms (Patil 1992), which have been reported to abate spontaneously after 1 to 3 weeks (Patil 1992) or to respond to a decrease in dosage
APA PsycNet
Emergence of obsessive compulsive symptoms during treatment with clozapine.
Explored the relationship between clozapine, a potent antagonist of serotonin receptors, and obsessive-compulsive symptoms, which have been linked to deficient serotonin. The treatment of 49 chronic schizophrenic patients with clozapine was reviewed, and 5 patients (aged 33–41 yrs) were identified who experienced either de novo obsessive-compulsive symptoms or exacerbation of preexistent symptoms. Clinical details are provided for each case. It is concluded that clozapine may produce or unmask obsessive-compulsive symptoms. This may reflect a variation on the normal course of clinical improvement or may more specifically result from clozapine’s atypical pattern of CNS receptor antagonism. (PsycINFO Database Record (c) 2016 APA, all rights reserved)
https://www.ingentaconnect.com/content/ben/cn/2012/00000010/00000001/art00009
Finally, significant correlations of OCS-severity with duration of treatment, dose and serum levels suggest clozapine-induced OCS.
APA PsycNet
Reports the case of a 46-yr-old man with chronic paranoid schizophrenia who experienced obsessive-compulsive behaviors (OCBs) after initiation of clozapine (350 mg/day) treatment. Treatment with sertraline (75 mg/day) reduced the S’s repetitive counting and checking behaviors. Clozapine’s antiserotonergic properties could be related to the emergence of OCBs
https://onlinelibrary.wiley.com/doi/full/10.1111/j.1440-1819.2005.01362.x
The results support earlier findings which suggest that clozapine produces or unmasks OCS.
Higher Plasma Drug Concentration in Clozapine-treated Schizo... : Therapeutic Drug Monitoring
The authors suggest that the emergence of these side effects may be related to higher Cps of clozapine and clinicians should routinely check for and manage these side effects.