Over the past decade, a growing body of evidence suggests that second-generation antipsychotics such as Risperidone are effective in the treatment of patients with psychosis (
27). Current research evidence strongly suggests a relationship between methamphetamine use and the development of acute psychosis. First, early studies demonstrated that methamphetamine could trigger acute psychosis in healthy individuals (
28).
The positive symptoms of methamphetamine psychosis are similar to those of paranoid schizophrenia, consisting mainly of delusions and hallucinations. The recurrent nature of methamphetamine psychosis is also suggested as another apparent similarity, as recurring methamphetamine psychosis could be similar to schizophrenia (
29).
The current pilot study is one of the few studies in Iran that considered MA psychosis treatment with Haloperidol and Risperidone among a group of patients, who were hospitalized at Razi psychiatric hospital. A few studies from Iran have targeted treating MAP. The study findings suggested that both Haloperidol and Risperidone were effective for the treatment of MAP yet there was no significant difference between the two antipsychotic medications. A few studies in other countries have addressed the treatment of MAP with antipsychotic medications. The findings of the current study are in contrast with the study findings of Green et al. (2002) (
30), who found that Haloperidol was more effective in treating psychosis in comparison with Risperidone.
In another study, it was found that making a treatment transition from Haloperidol to Risperidone among Schizophrenic patients reduced the scores of subscales of positive, negative and general psychosis symptoms (
31). Zhang et al. (2001) (
32) found that the general symptoms of psychosis in the Risperidone group were significantly improved compared with the Haloperidol group. A study found that Risperidone was superior in the treatment of symptoms of psychosis compared with Haloperidol (
33).
The reported changes in these studies can be the result of several factors. First, the dose of use may impact the treatment effects. In fact, there is still no agreement on the dose required to treat positive symptoms of MAP, especially for Risperidone. There are no studies that have examined the best dosage. There is only evidence that higher doses of antipsychotic medications have better effectiveness compared with lower ones. Further studies of this issue are still required.
It should be noted that positive symptoms of MAP are associated with considerable health service utilization and increased psychiatric symptoms over time (
34). Little is known about the pharmacological therapies of patients with MAP in Iran. In addition, the most effective regime for stabilizing patients with MAP still needs to be studied in Iran. Methamphetamine users are vulnerable to MAP, either as a result of exacerbation of symptoms of underlying psychotic disorders (
35) or emerging new psychotic symptoms during intoxication and withdrawal stages (
36); recurrence can occur in response to psychological stressors even in the absence of methamphetamine use (
37).
Recently, however, the picture of success for these antipsychotic medications has become somewhat vague. Patients diagnosed with positive symptoms of MAP should be monitored more closely, in particular for signs of a chronic development.
5.1. Limitations and Suggestions
The current study also had some limitations as follows: the study sample was limited to only one psychiatric center. Therefore, data generalization is difficult. Because of a number of problems such as difficulty in sample recruitment, the sample size was small. Further studies with more representative numbers of samples are suggested. Because of psychiatric treatment of patients, it was difficult to have further follow-ups. Therefore, designing and conducting research studies with more follow-up sessions are suggested. In this study, we compared the therapeutic effectiveness of Haloperidol with Risperidone in the treatment of MAP yet further studies with Placebo groups are still suggested. However, the current study is one the few studies in Western Asia, especially the Persian Gulf region, which targeted treating MAP with antipsychotic medication.