Figure 2.

Effects of khat chewing and paranoid schizophrenia on plasma level of serotonin (A) and its related metabolite HIAA (B).

Notes: Each value represents as mean ± SEM. *For comparison between khat-chewers and non-chewers between groups and within groups, ^▼for comparison between SNKch or SNKcr and HNKc, and ^⋄for comparison between SKch or SKcr and HKc. Note that mostly rest of all other comparisons were significant. ^⋄P<0.05; ***^{,▼▼▼,⋄⋄⋄}P<0.001.

Abbreviations: H, healthy; N, non; K, khat; c, chewing; S, schizophrenic; h, haloperidol; r, risperidone; HIAA, hydroxyindoleacetic acid; SE, standard error; SEM, standard error of the mean.