I can't read the fulltext because I'm no longer associated with a university, but to break down the abstract (definitions are from Merriam-Webster medical dictionary, Free Dictionary, and Wikipedia):
The addition of valproic acid to risperidone significantly reduced total scores of PANSS positive symptoms, especially excitement and hostility scores, but did not change SAS scores.
PANSS is an assessment of symptom severity for schizophrenic patients. SAS is the Simpson-Angus scale, which is used to assess the cumulative severity of extrapyramidal syndromes (one of the more common and severe side effects of schizophrenia medications). Therefore, they are claiming that the addition of valproic acid is beneficial to patients without causing an increased risk of serious side effects (or at least movement problems).
Addition of valproic acid did not alter plasma concentrations of risperidone or 9-hydroxyrisperidone or active moiety, and the risperidone/9-hydroxyrisperidone ratio.
It does not seem to affect either the uptake or metabolic breakdown of the drug; your body can still receive and process your original medication properly without change.
The combination of valproic acid with risperidone decreased plasma levels of HVA, but not those of MHPG; additionally, treatment with this combination was found to reduce dopaminergic activity.
HVA is Homovanillic acid, which is associated with dopamine levels in the brain. MHPG is " a metabolite of norepinephrine that is reported for some patients to fall to lower levels during periods of depression"
So, here they are saying that the addition of valproic acid causes a measurable decrease in dopamine levels/activity, but doesn't seem to decrease other significant neurotransmitters which could cause depression. I imagine in the full article they look at other transmitters as well. Decreasing dopaminergic activity is one of the effects of risperidone in the first place, though unlike other drugs in its class, risperidone works primarily through serotonin antagonism and has less of an impact on dopamine. So it is interesting to note that it is this area, where risperidone is less effective than other similar drugs, that valproic acid works.
CONCLUSION:
These results suggest that the addition of valproic acid to risperidone is both effective and well tolerated for treating excitement and impulsiveness in schizophrenic patients without influencing the metabolism of risperidone, and treatment with valproic acid and risperidone.
This pretty much stands for itself, though I hope my breakdown helped show how it ties in with the rest better. As a side note, the last sentence of it is terribly written.
Hope I was any help at all!!
