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Low versus standard dose mCPP challenge in obsessive-compulsive patients
S Erzegovesi1, L Martucci, M Henin
1Department of Neuropsychiatric Sciences, S. Raffaele Hospital, University of Milan School of Medicine, Milano, Italy.
Abstract:
In several reports, the acute oral administration of the partial serotonergic agonist meta-chlorophenylpiperazine (mCPP) in dose of 0. 5 mg/kg induced a significant worsening of obsessive-compulsive (OC) symptoms in a number of patients. The aim of our study was to test the 0.25 mg/kg mCPP dose, which was hypothesized to be more specific for OC symptoms and was until now tested only on healthy subjects. In a double-blind, controlled crossover study, 12 OC patients participated on three test days, receiving one of the following on each day: oral 0.5 mg/kg mCPP (standard dose), 0.25 mg/kg mCPP (low dose), or placebo. Behavioral ratings were obtained by means of Visual Analogue Scale (VAS) ratings. The low dose mCPP induced a significant worsening of OC symptoms in 50% (6/12) of the patients, whereas 8.3% (1/12) of the patients showed a worsening after the standard dose. On the other hand, only the standard dose mCPP induced a worsening, although not statistically significant, of anxiety ratings. Our data show that the 0.25 mg/kg dose mCPP induces a specific response in OC symptoms, with little anxiogenic effect. To confirm these preliminary data, future studies will be needed on larger samples and with more sensitive rating scales.
Insights
A lower dose of meta-chlorophenylpiperazine (mCPP) specifically worsened obsessive-compulsive (OC) symptoms in half of patients, unlike the standard dose which showed minimal effects on anxiety.
Area of Science:
- Neuroscience
- Psychopharmacology
- Clinical Psychology
Background:
- Meta-chlorophenylpiperazine (mCPP), a partial serotonergic agonist, has been associated with worsening obsessive-compulsive (OC) symptoms at a 0.5 mg/kg dose.
- Previous research on the 0.25 mg/kg mCPP dose was limited to healthy subjects, leaving its specific effects on OC patients uninvestigated.
Purpose of the Study:
- To evaluate the efficacy of a lower dose (0.25 mg/kg) of mCPP in specifically targeting and potentially exacerbating OC symptoms.
- To compare the effects of the low-dose mCPP against a standard dose (0.5 mg/kg) and placebo in OC patients.
Main Methods:
- A double-blind, controlled crossover study involving 12 patients diagnosed with OC disorder.
- Participants received oral administrations of 0.5 mg/kg mCPP, 0.25 mg/kg mCPP, or placebo on separate test days.
- Behavioral symptom severity was assessed using Visual Analogue Scale (VAS) ratings.
Main Results:
- The 0.25 mg/kg mCPP dose significantly worsened OC symptoms in 50% (6/12) of the patients.
- In contrast, the standard 0.5 mg/kg mCPP dose led to symptom worsening in only 8.3% (1/12) of patients.
- The standard dose showed a non-significant trend towards increased anxiety ratings, while the low dose had minimal anxiogenic effects.
Conclusions:
- The 0.25 mg/kg mCPP dose appears to elicit a specific worsening of OC symptoms with a reduced potential for inducing anxiety.
- These preliminary findings suggest a potential therapeutic or diagnostic application for lower mCPP doses in OC disorder.
- Further research with larger sample sizes and more sensitive rating scales is recommended to validate these results.