Cannabis use and abuse correlates in a homogenous South African schizophrenia population

Abstract

<p><strong>Objective.</strong> Worldwide, cannabis is the most widely used illicit substance, and it has been identified as a correlate in schizophrenia samples for poorer symptomatic and functional outcomes in many international studies. The object of this retrospective study was to identify the prevalence of cannabis use/abuse and the demographic and clinical correlates therefor in a large homogeneous South African schizophrenia population.</p><p><strong>Methods.</strong> As part of a large genetic study, 547 subjects with a diagnosis of schizophrenia were recruited. Demographic and clinical data were collected and each participant underwent a urinary drug screen. Use/abuse of cannabis was defined as using cannabis more than 21 times in a single year. Subjects with and without cannabis use/abuse were statistically compared. <strong></strong></p><p><strong>Results.</strong> Significant differences between the two groups were found in terms of gender, marital status, age of onset of schizophrenia, number of hospitalisations and relapses, alcohol abuse, smoking, the Scale for the Assessment of Positive Symptoms (SAPS) scores for hallucinations, delusions, bizarre behaviour and formal thought disorder, and the Scale for the Assessment of Negative Symptoms (SANS) score for avolition/apathy. <strong></strong></p><p><strong>Conclusion.</strong> The prevalence of cannabis use/abuse in this study was high, and our findings were comparable with those of previous international studies. Abuse/use started mainly in the teenage years, was more prevalent among males than females, and was associated with negative overall outcomes. There was also a positive correlation between cannabis and nicotine and alcohol use/abuse. Determination of cannabis abuse based solely on history was found to be reliable, and urine cannabis testing appeared to be of limited value in routine management of this group of schizophrenic patients.</p>

Cannabis use predicts shorter duration of untreated psychosis and lower levels of negative symptoms in first-episode psychosis: a South African study

“…13 In contrast to previous studies 1,6,14,15 , we found a significant association between cannabis use and shorter DUP and a trend association between the use of cannabis and a relative absence of negative symptoms. Also, unlike these studies, we did not find increased positive symptoms, nor was there any association with AO (a finding that has been reported from both developed and developing countries [3][4][5][12][13][14][15] ). Clearly then the relationship between cannabis use and onset of FEP is complex.…”

“…The ethnic distribution of our sample was consistent with that of the local population while the prevalence of cannabis use/abuse (35%) approximated that reported in other African studies: 38% in the Gambia 12 and 35-49% in South Africa. 3,13 The slight gender bias in prevalence of cannabis use observed in our study (37% of males and 28% of females) was also similar to that reported by Roos and colleagues. 13 In contrast to previous studies 1,6,14,15 , we found a significant association between cannabis use and shorter DUP and a trend association between the use of cannabis and a relative absence of negative symptoms.…”

“…Although we relied solely upon self-and caregiver reporting to establish cannabis use, we are satisfied that this is a valid method -Koen and colleaguescompared urine THC testing with self-report of cannabis use and concluded that determination based solely on history is reliable and that THC testing "appears to be of limited value". 3 Generalization from our results is limited by several factors (some mentioned above) including the fact that ours was an entirely hospital based sample which is likely not to represent all patients in this area. Also, the high rate of HIVseropositivity (22%) in our sample may be a confounder.…”

“…The relationship then between the clinical presentation of FEP and cannabis abuse is complex and warrants further investigation, especially within the South African context where this pattern of co-morbidity is so prevalent. 3 It is therefore relevant to explore any associations that may exist between recent/current cannabis use/abuse and clinical features of FEP that previously have been shown to have prognostic value (including age of onset (AO), duration of untreated psychosis (DUP), positive, negative, general psychopathology and depressive symptoms). Importantly, while these features may be predictive of outcome, they are not measures of outcome itself -they might better be considered proxies for outcome.…”

Contributions from the South African Society of Psychiatrists (SASOP) to the National Mental Health Action Plan

“…Objective 6: Intersectoral collaboration (Table 6) • Examples of cases in psychiatry where intersectoral collaboration is central include: community-based residential and psycho-social rehabilitation facilities and services; forensic psychiatry; substance abuse and addiction; [31,32] child and adolescent psychiatry, and geriatric psychiatry. [33] Objective 7: Human resources for mental health (Table 7) • …”