Catha edulis chewing effects on treatment of paranoid schizophrenic patients

Neuropsychiatr Dis Treat. 2015 Apr 15:11:1067-76. doi: 10.2147/NDT.S81011. eCollection 2015.


Background: The current study's aim is to evaluate the possible interaction effects of khat chewing on treatment of paranoid schizophrenic patients.

Patients and methods: In the study group, 42 male subjects suffered from paranoid schizophrenia and were classified according to their khat chewing habits into two subgroups: either khat-chewer subgroup (SKc; n=21; r=11, h=10) or non-khat-chewer subgroup (SNKc; n=21, r=11, h=10). Each subgroup was further subdivided according to type of treatment into r (risperidone) and h (haloperidol). Healthy male subjects (37) were subdivided into healthy khat-chewer as positive controls (HKc, n=17) and healthy non-khat-chewer as negative controls (HNKc, n=20). Plasma dopamine, 3,4-dihydroxyphenylacetic acid (DOPAC), homovanillic acid, 5-hydroxytryptamine (serotonin), 5-hydroxyindoleacetic acid, epinephrine, and norepinephrine were estimated.

Results: ANOVA and post hoc analysis showed that dopamine was illustrating significant elevation in all khat chewing groups. DOPAC was illustrating significant decrease in all khat chewing groups with an interesting outcome showing significant increase in DOPAC in SNKcr group due to risperidone effect. Homovanillic acid, serotonin, hydroxyindoleacetic acid, and norepinephrine were illustrating significant elevations in all khat chewing groups. Epinephrine was illustrating significant elevation in all chewers than non-chewers groups. Unexpected significant decrease in epinephrine in the SNKcr group indicated that risperidone drug is decreasing epinephrine through indirect mechanism involving calcium.

Conclusion: Khat chewing in schizophrenic patients is contraindicated because it aggravates the disease symptoms, attenuates all used treatment medications, and deteriorates all biochemical markers of the patients.

Keywords: dopamine; epinephrine; khat; norepinephrine; schizophrenia; serotonin.