Dopamine
Kava drinking was seen to reduce behaviors associated with issues related to psychosis in aboriginal communities in the Northern Territory of Australia which prompted further studies in regards to kava and psychosis. Psychosis is an abnormal condition of the mind that results in difficulties determining what is real and what is not real. Symptoms may include delusions and hallucinations. Other symptoms may include incoherent speech and behavior that is inappropriate for the situation. There may also be sleep problems, social withdrawal, lack of motivation, and difficulties carrying out daily activities. Psychosis can have serious outcomes [1]. Dopamine has been thought to play a major role in the development of this disease. In the dopamine hypothesis, dopamine is overactive in the mesolimbic areas and underactive in the prefrontal cortex. Dysregulation of dopamine is also seen in the amygdala, involved in emotional processing [2].
Researchers induced amphetamine psychosis in mice and studied the results of adding kava to the diet of these mice with psychosis. They treated each mouse with either control, amphetamine, kava extract alone, and kava extract and amphetamine. When kava and amphetamine were used together it was shown that it reduced the normal behavior of mice under the influence of amphetamines alone. Evidence from this study suggest that kava plays a larger role in modulating dopamine levels across the brain, decreasing levels in some areas while increasing levels in others [3]. Direct clinical evidence of this reduction of dopamine can be seen in kava drinkers that drink far too much. The state is referred to as dyskinesia. Dyskinesia is defined as the abnormality or impairment of voluntary movement. It’s the dance like movements seen when a kava drinker is having a difficult time controlling the use of their arms and legs.
Kava has also been shown to bind in the type 2 dopamine receptors [4]. This receptor has been found to be the main receptor for most antipsychotic drugs that treat psychotic disorders such as schizophrenia.
The results of these studies lend evidence for another possible therapeutic avenue for kava, adding to its broadening medicinal applications.
[1] Psychosis. (2021, January 24). Retrieved January 27, 2021, from https://en.wikipedia.org/wiki/Psychosis
[2] Robertson, S. (2020, January 23). Dopamine and Psychosis. Retrieved January 27, 2021, from https://www.news-medical.net/health/Dopamine-and-Psychosis.aspx
[3] B. Krum, Kava decreases the stereotyped behavior induced by amphetamine in mice, Journal Of Ethnopharmacology. 265 (2021). doi:https://doi.org/10.1016/j.jep.2020.113293.
[4] Dinh LD, Simmen U, Bueter KB, Bueter B, Lundstrom K, Schaffner W. Interaction of various Piper methysticum cultivars with CNS receptors in vitro. Planta Med. 2001 Jun;67(4):306-11. doi: 10.1055/s-2001-14334. PMID: 11458444. https://pubmed.ncbi.nlm.nih.gov/11458444/
