Abstract
Fresh leaves of the Catha edulis plant (khat) have been chewed for centuries amongst people from countries bordering the Red Sea and the east coast of Africa. The two primary ingredients in khat, cathinone and cathine share structural and functional similarities with amphetamine and ephedrine. Although widely accepted as a social lubricant in certain cultures, reports of the adverse psychological and physical side effects of khat have been recognized [1]. Two case reports in this journal [2,3] have raised the spectre of khat use becoming increasingly more problematic in Australia with the increasing number of immigrants to this country from parts of Africa where the use of khat is acceptable. However, since these concerns were first raised in 1994 only one case of khat-induced psychosis has been reported from Australia [3]. We describe another case of khat-induced psychosis and speculate on the possible causes for the low yield of khat-related problems in Australia.
A 44 year old unemployed agricultural worker from Somalia, resident in Australia for the last 15 years, presented to hospital with a week-long history of paranoid delusions of a persecutory nature, insomnia and anorexia. He believed his wife and others were involved in an elaborate plot to incriminate him over terrorist activities and possession of khat. Mental state examination revealed behavioural disorganization, pressured speech, euphoria, delusions of reference and persecution as already elaborated. He acknowledged using khat for the last 30 years. Use had increased in the last 2 years. He cited unemployment, boredom, social isolation and marital difficulties as contributing to this. He was consuming half a bag a day sourced from a local dealer for AU$25-30/bag. He had also succeeded in growing a small shrub in his backyard and this supplemented his supply. He smoked 10 cigarettes a day. He denied the use of alcohol or other illicit drugs. A urine drug screen at admission was negative. Investigations including a CT head scan, a complete blood count, electrolytes, liver enzymes and thyroid function test were normal. There was no family history or prior history of any neuropsychiatric morbidity. HB was treated with a combination of risperidone and lorazepam with which his psychosis resolved swiftly. He was discharged to the care of his family in 2 weeks. Detailed consultations with the family and the larger community were held in conformity with cultural norms. Suggestions of khat being implicated in the causation of psychosis were met with scepticism as a large number of those present had previously used khat without event. Psychoeducation involved discussions around the relationship between dose and causation, individual susceptibility and the importance of abstinence to maintain remission.
This patient represents the typical clinical presentation for an individual with khat-induced psychosis [2,4]. The relatively late age for the appearance of an index episode of psychosis in the context of increased khat use and the absence of a family history of psychosis were other factors that would support the diagnosis of a possible drug-induced psychosis.
Several possible reasons could explain the paucity of reports on khat-related difficulties in Australia. The long distance from the major khat producing regions would suggest a paucity of supply. However, anecdotal evidence, including the ease with which our client was able to access khat in South Australia, would suggest that khat is readily available and considerably cheaper than several other substances of abuse in vogue. The rather small population of immigrants from khat using regions could be another variable. However, since these concerns were first raised, the population of immigrants in Australia from khat using regions has quadrupled (approximately 40,000 [2,5]). Additionally, surveys suggest that immigrant communities might be more susceptible to greater khat use resulting from a combination of unemployment, increased free time and a desire to maintain cultural identity by chewing khat [1].
Important issues related to poor case recognition also include diagnostic difficulties. There is considerable unfamiliarity about khat and its effects amongst Australian doctors. This is likely to lead to a diagnosis of schizophrenia especially with a negative urine drug screen. Current drug screens are unlikely to detect the metabolites of khat. Language difficulties reduce the chance of eliciting a positive history of khat use. Patients or relatives from cultures where khat receives social sanction are unlikely to report a history of khat use as a possible etiological culprit. New immigrants unsure of khat-related legislation are unlikely to volunteer information that may cause legal strife and adversely impact on their tenure in Australia. The diagnosis in this case was fortuitous because the patient's khat use formed a part of his paranoid delusions.
The last possibility we raise is the validity of this diagnostic entity. Researchers have argued on both sides of an association between khat and the induction of a psychotic state [1,6,7]. Despite a sizeable number of case reports worldwide and a possible mechanism of action some researchers argue that both cathine and cathinone are not as potent as amphetamines and therefore drawing comparisons is inaccurate. It is also unclear whether khat induces a psychosis or merely precipitates this in already vulnerable individuals [6].
While the jury is out on the association between khat and a possible psychotic illness, the authors would advise a cautious approach to the phenomenon of khat on our shores. An increased awareness amongst health professionals and further robust research are needed to inform policy in health care and law enforcement. No fair policy can ignore that khat, like several other psychoactive substances, has important socioeconomic perspectives and social significance amongst users [4].