L. Koen | Stellenbosch University (original) (raw)

Papers by L. Koen

South African Family Practice, 2004

Suicide is ranked as the ninth overall cause of death in the United States. Whether a true suicid... more Suicide is ranked as the ninth overall cause of death in the United States. Whether a true suicide or parasuicide attempt, it remains a psychiatric emergency for which each clinician needs an appropriate management strategy. (SA Fam Pract 2004;46(8): 38-39)

South African Family Practice, 2004

Suicide is ranked as the ninth overall cause of death in the United States. Whether a true suicid... more Suicide is ranked as the ninth overall cause of death in the United States. Whether a true suicide or parasuicide attempt, it remains a psychiatric emergency for which each clinician needs an appropriate management strategy.

South African Journal of Psychiatry, 2008

Objective. Clozapine is the current gold standard treatment for severe treatment-refractory schiz... more Objective. Clozapine is the current gold standard treatment for severe treatment-refractory schizophrenia, but even so 40 - 70% of these patients will continue to experience disabling symptoms when treated with clozapine monotherapy. Current clinical practice at Stikland Hospital holds that known clozapine-refractory schizophrenia patients who relapse due to non-compliance are treated with an initial combination of clozapine and ECT (if able to consent) when readmitted. The purpose of this study was to evaluate the validity of this practice. Methods. Patients were divided into an ECT (EG) and non-ECT (CG) group. Clozapine was started and ECT administered as per protocol. Demographic data, psychiatric and medication history and data concerning adverse events were collected. Positive and Negative Symptom Scale (PANSS) scores were done at baseline and at days 21 and 42. Results. At discharge, although numerically the average increase in clozapine dose was lower and the reduction in len...

South African Journal of Psychiatry, 2015

Introduction. Disrupted perception, i.e. lack of self-awareness, in psychosis impacts required me... more Introduction. Disrupted perception, i.e. lack of self-awareness, in psychosis impacts required mental effort during information processing. Mental effort increases when demands of a task increase; previously this relationship has been identified by increased beta band activity over the left parietal cortex in healthy controls. In the current study we hypothesised that individuals with diagnosis of a psychotic disorder will not show this relationship, owing to their lack of self-awareness and insight when reporting subjective measures of mental effort. Methods. This study included 83 participants with one of three diagnoses: schizophrenia (SZ, n=29), bipolar I disorder psychosis (BPD, n=28), or methamphetamine-induced psychosis (MPD, n=24), and socio-demographic controls (n=32). All participants underwent electroencephalography (EEG) and relative band frequency activities were correlated with reported mental effort during three conditions: resting eyes open (REO), resting eyes closed (REC), and during an attention task, a continuous performance task (CPT). In addition several clinical scales were performed to address current symptom presentation. Results. First, perceived mental effort reported by the BDP group during REO was negatively correlated with relative alpha band power over the frontal and parietal cortices, and with relative beta band power over the cingulate cortex. Relative theta band power was positively correlated with perceived mental effort over the left frontal cortex, relative beta band power over the parietal cortex, and relative delta band power over the cingulate and parietal cortices during REO. Second, perceived mental effort reported by the MPD group was negatively correlated with their Positive and Negative Syndrome Scale (PANSS) scores. Conclusion. The BPD group showed strong relationships with EEG band frequency activity and perceived mental effort during relaxed wakefulness; we suggest that this may relate to the reported increase in psychosomatic awareness which is present in BPD. The MPD group reported lower perceived mental effort when their psychotic symptomatology was high, suggesting disrupted perception. In search of an affordable, effective post-discharge intervention: A randomised control trial assessing the influence of a telephonebased intervention on readmissions for patients with severe mental illness in a developing country

African journal of psychiatry, 2008

The inclusion of dimensional elements in the psychiatric diagnostic systems have been advocated f... more The inclusion of dimensional elements in the psychiatric diagnostic systems have been advocated for many years, however it has been resisted due to concerns about clinical utility. Recent suggestions have been for a combination of categorical and dimensional data in future diagnostic classification systems. In this paper we discuss the overlap in symptom complexes between mood disorders and schizophrenia and a multi-dimensional model of the mood-psychosis interface. We propose that the personality diagnoses should be included in Axis I and suggest the inclusion of a five factor dimensional diagnosis of mood and psychotic disorders on Axis II of DSM-V/ICD-11.

BMC psychiatry, Jan 27, 2006

Demonstrating an association between physical malformation and schizophrenia could be considered ... more Demonstrating an association between physical malformation and schizophrenia could be considered supportive of a neurodevelopmental origin of schizophrenia and may offer insights into a critical period for the development of this illness. The aim of our study was to investigate whether differences in the presence of minor physical anomalies could be demonstrated between schizophrenia sufferers and normal controls in a Xhosa population with a view to identifying a means of subtyping schizophrenia for use in future genetic studies. Sixty-three subjects with schizophrenia (21 sibling pairs, 1 sibship of four and a group of probands with an affected non-participating sibling (n = 17)), 81 normal controls (37 singletons and 22 sibling pairs) of Xhosa ethnicity were recruited. Each participant was then examined for minor physical anomalies using the Modified Waldrop scale. The relationship between each of the morphological features and the presence of an affected sib was examined using th...

Journal of Religion and Health, 2014

Here, we assessed for the first time the frequency of religious delusions and the effect of treat... more Here, we assessed for the first time the frequency of religious delusions and the effect of treatment on religiosity and the phenomena of religious delusions in a Xhosa schizophrenia population. Religious delusions were present in 42 (70 %) participants, and treatment significantly reduced religiosity (p = 0.02) as well as mean scores for certain phenomena associated with the delusions including changes in both thinking (p = 0.0001) and behaviour (p = 0.0001), as well as affective response to the delusion (p = 0.0001) The high frequency of religious delusions may indicate a higher tolerance for religious delusions in this community. It is therefore important to educate spiritual leaders on mental illness.

Community Mental Health Journal, 2016

South African Medical Journal, 2012

South African Journal of Psychiatry, 2014

ABSTRACT Background. Clozapine use is known to be associated with significant side-effects, inclu... more ABSTRACT Background. Clozapine use is known to be associated with significant side-effects, including prolongation of the QT-interval, agranulocytosis and metabolic syndrome. However, few data exist on the prevalence of clozapine side-effects in patients of Xhosa descent. Objective. To gather data from Xhosa patients with schizophrenia to establish the prevalence of clozapine side-effects in this population. Methods. Twenty-nine Xhosa patients with schizophrenia (as per the Diagnostic and Statistical Manual of Mental Disorders (DSM-IV-TR)) who had been receiving clozapine treatment for > 1 year on an outpatient basis were selected for inclusion. All patients were participating in a genetics study in the Cape Metropolitan area. The participants were evaluated for the presence of side-effects (tests including an electrocardiogram, white blood cell count (WCC) and fasting blood glucose). Results. The prevalence of metabolic syndrome was 44.8% (95% confidence interval (CI) 26.7 - 62.9) and of undiagnosed diabetes mellitus 13.8% (95% CI 1.24 - 26.34). There was a significant association between metabolic syndrome and body mass index (BMI) (p < 0.01). The mean (SD) WCC was 7.8 x 10(9)/L (2.8), with 3.4% of the subjects having a WCC < 3.5 x 10(9)/L. Sedation (82.8%; 95% CI 69.0 - 96.5), hypersalivation (79.3%; 95% CI 64.6 - 94.1) and constipation (44.8%; 95% CI 26.7 - 62.9) were common. The mean QT-interval was 373.8 (35.9) ms and 10% had a corrected QT-interval > 440 ms. There was an association between the duration of clozapine treatment and QT-interval (with Bazett's correction). Conclusion. The high prevalence of metabolic syndrome and undiagnosed diabetes mellitus in this sample points to a need to monitor glucose levels and BMI on a regular basis. A larger study should be done to accurately quantify the differences in prevalence of side-effects between population groups.

South African Journal of …, 2008

... Am J Psychother 1987; 41: 409-416. 7. Greenberg D, Witztum E, Levy A. Hoarding as a psychiatr... more ... Am J Psychother 1987; 41: 409-416. 7. Greenberg D, Witztum E, Levy A. Hoarding as a psychiatric symptom. J Clin Psychiatry 1990; 51: 417-421. ... 17. Niehaus DJH, Koen L, Muller J, et al. OCD – prevalence in Xhosa speaking schizophrenia patients. ...

In het eindexamenprogramma van de natuurwetenschappelijke vakken op de middelbare school worden e... more In het eindexamenprogramma van de natuurwetenschappelijke vakken op de middelbare school worden een aantal onderzoeksvaardigheden beschreven die leerlingen behoren te beheersen bij het behalen van een diploma (CEVO, 2009). Als natuurkunde docenten in opleiding, ...

BMC Psychiatry, 2008

Background: Severe pressures on beds in psychiatric services have led to the implementation of an... more Background: Severe pressures on beds in psychiatric services have led to the implementation of an early ("crisis") discharge policy in the Western Cape, South Africa. The study examined the effect of this policy and length of hospital stay (LOS) on readmission rates in one psychiatric hospital in South Africa.

European Neuropsychopharmacology, 2015

African journal of psychiatry, 2008

Although the integration of psychiatric services into the community has potentially been benefici... more Although the integration of psychiatric services into the community has potentially been beneficial to many patients, this transition has not been without problems. A major obstacle to establishing successful community-based treatment in South Africa has been that the reduction in number of inpatients beds did not coincide with the development of adequate community resources. This, in combination with our patients' poor socio-economic circumstances, has contributed to a substantial increase in the so-called "revolving door" or high frequency use phenomenon in state psychiatric facilities. Clearly, there is need for a renewed approach to address this problem in our setting. With this in mind the APH in the Western Cape appointed three community treatment teams in January 2007. This publication serves to give an overview of the Stikland Psychiatric Hospital team's experiences in the first 12 months since establishment. To date, we have been confronted by several chal...

West African journal of medicine

Initially the risk of HIV in people with severe mental illness (SMI) was grossly underestimated, ... more Initially the risk of HIV in people with severe mental illness (SMI) was grossly underestimated, but comparisons with the general population have in fact revealed higher infection rates in this particular group. Not only are patients with SMI sexually active but it has also been demonstrated that this group and especially patients with schizophrenia are less knowledgeable about HIV risk behaviours than the general population. Currently no data concerning the participation in and knowledge of HIV/AIDS risk behaviours by South African schizophrenic patients is available. Patients with schizophrenia and a control-group were recruited from community clinics in the Western Cape, South Africa, whereafter 43 from each group were matched (race, age, sex). The patient group was subjected to a structured clinical interview and both groups completed the AIDS Risk Behaviour Assessment (ARBAQ) and Knowledge (ARBKQ) Questionnaires. Comparatively, significant knowledge deficits could be demonstrat...

Schizophrenia Research, 2006

Frontiers in Genetics, 2013

The CYP3A4 enzyme is the most abundant human cytochrome P450 (CYP) and is regarded as the most im... more The CYP3A4 enzyme is the most abundant human cytochrome P450 (CYP) and is regarded as the most important enzyme involved in drug metabolism. Inter-individual and inter-population variability in gene expression and enzyme activity are thought to be influenced, in part, by genetic variation. Although Southern African individuals have been shown to exhibit the highest levels of genetic diversity, they have been under-represented in pharmacogenetic research to date. Therefore, the aim of this study was to identify genetic variation within CYP3A4 in three South African population groups comprising of 29 Khoisan, 65 Xhosa and 65 Mixed Ancestry (MA) individuals. To identify known and novel CYP3A4 variants, 15 individuals were randomly selected from each of the population groups for bi-directional Sanger sequencing of ~600 bp of the 5'-upstream region and all thirteen exons including flanking intronic regions. Genetic variants detected were genotyped in the rest of the cohort. In total, 24 SNPs were detected, including CYP3A4(*)12, CYP3A4(*)15, and the reportedly functional CYP3A4(*)1B promoter polymorphism, as well as two novel non-synonymous variants. These putatively functional variants, p.R162W and p.Q200H, were present in two of the three populations and all three populations, respectively, and in silico analysis predicted that the former would damage the protein product. Furthermore, the three populations were shown to exhibit distinct genetic profiles. These results confirm that South African populations show unique patterns of variation in the genes encoding xenobiotic metabolizing enzymes. This research suggests that population-specific genetic profiles for CYP3A4 and other drug metabolizing genes would be essential to make full use of pharmacogenetics in Southern Africa. Further investigation is needed to determine if the identified genetic variants influence CYP3A4 metabolism phenotype in these populations.

South African Family Practice, 2004

Suicide is ranked as the ninth overall cause of death in the United States. Whether a true suicid... more Suicide is ranked as the ninth overall cause of death in the United States. Whether a true suicide or parasuicide attempt, it remains a psychiatric emergency for which each clinician needs an appropriate management strategy. (SA Fam Pract 2004;46(8): 38-39)

South African Family Practice, 2004

Suicide is ranked as the ninth overall cause of death in the United States. Whether a true suicid... more Suicide is ranked as the ninth overall cause of death in the United States. Whether a true suicide or parasuicide attempt, it remains a psychiatric emergency for which each clinician needs an appropriate management strategy.

South African Journal of Psychiatry, 2008

Objective. Clozapine is the current gold standard treatment for severe treatment-refractory schiz... more Objective. Clozapine is the current gold standard treatment for severe treatment-refractory schizophrenia, but even so 40 - 70% of these patients will continue to experience disabling symptoms when treated with clozapine monotherapy. Current clinical practice at Stikland Hospital holds that known clozapine-refractory schizophrenia patients who relapse due to non-compliance are treated with an initial combination of clozapine and ECT (if able to consent) when readmitted. The purpose of this study was to evaluate the validity of this practice. Methods. Patients were divided into an ECT (EG) and non-ECT (CG) group. Clozapine was started and ECT administered as per protocol. Demographic data, psychiatric and medication history and data concerning adverse events were collected. Positive and Negative Symptom Scale (PANSS) scores were done at baseline and at days 21 and 42. Results. At discharge, although numerically the average increase in clozapine dose was lower and the reduction in len...

South African Journal of Psychiatry, 2015

Introduction. Disrupted perception, i.e. lack of self-awareness, in psychosis impacts required me... more Introduction. Disrupted perception, i.e. lack of self-awareness, in psychosis impacts required mental effort during information processing. Mental effort increases when demands of a task increase; previously this relationship has been identified by increased beta band activity over the left parietal cortex in healthy controls. In the current study we hypothesised that individuals with diagnosis of a psychotic disorder will not show this relationship, owing to their lack of self-awareness and insight when reporting subjective measures of mental effort. Methods. This study included 83 participants with one of three diagnoses: schizophrenia (SZ, n=29), bipolar I disorder psychosis (BPD, n=28), or methamphetamine-induced psychosis (MPD, n=24), and socio-demographic controls (n=32). All participants underwent electroencephalography (EEG) and relative band frequency activities were correlated with reported mental effort during three conditions: resting eyes open (REO), resting eyes closed (REC), and during an attention task, a continuous performance task (CPT). In addition several clinical scales were performed to address current symptom presentation. Results. First, perceived mental effort reported by the BDP group during REO was negatively correlated with relative alpha band power over the frontal and parietal cortices, and with relative beta band power over the cingulate cortex. Relative theta band power was positively correlated with perceived mental effort over the left frontal cortex, relative beta band power over the parietal cortex, and relative delta band power over the cingulate and parietal cortices during REO. Second, perceived mental effort reported by the MPD group was negatively correlated with their Positive and Negative Syndrome Scale (PANSS) scores. Conclusion. The BPD group showed strong relationships with EEG band frequency activity and perceived mental effort during relaxed wakefulness; we suggest that this may relate to the reported increase in psychosomatic awareness which is present in BPD. The MPD group reported lower perceived mental effort when their psychotic symptomatology was high, suggesting disrupted perception. In search of an affordable, effective post-discharge intervention: A randomised control trial assessing the influence of a telephonebased intervention on readmissions for patients with severe mental illness in a developing country

African journal of psychiatry, 2008

The inclusion of dimensional elements in the psychiatric diagnostic systems have been advocated f... more The inclusion of dimensional elements in the psychiatric diagnostic systems have been advocated for many years, however it has been resisted due to concerns about clinical utility. Recent suggestions have been for a combination of categorical and dimensional data in future diagnostic classification systems. In this paper we discuss the overlap in symptom complexes between mood disorders and schizophrenia and a multi-dimensional model of the mood-psychosis interface. We propose that the personality diagnoses should be included in Axis I and suggest the inclusion of a five factor dimensional diagnosis of mood and psychotic disorders on Axis II of DSM-V/ICD-11.

BMC psychiatry, Jan 27, 2006

Demonstrating an association between physical malformation and schizophrenia could be considered ... more Demonstrating an association between physical malformation and schizophrenia could be considered supportive of a neurodevelopmental origin of schizophrenia and may offer insights into a critical period for the development of this illness. The aim of our study was to investigate whether differences in the presence of minor physical anomalies could be demonstrated between schizophrenia sufferers and normal controls in a Xhosa population with a view to identifying a means of subtyping schizophrenia for use in future genetic studies. Sixty-three subjects with schizophrenia (21 sibling pairs, 1 sibship of four and a group of probands with an affected non-participating sibling (n = 17)), 81 normal controls (37 singletons and 22 sibling pairs) of Xhosa ethnicity were recruited. Each participant was then examined for minor physical anomalies using the Modified Waldrop scale. The relationship between each of the morphological features and the presence of an affected sib was examined using th...

Journal of Religion and Health, 2014

Here, we assessed for the first time the frequency of religious delusions and the effect of treat... more Here, we assessed for the first time the frequency of religious delusions and the effect of treatment on religiosity and the phenomena of religious delusions in a Xhosa schizophrenia population. Religious delusions were present in 42 (70 %) participants, and treatment significantly reduced religiosity (p = 0.02) as well as mean scores for certain phenomena associated with the delusions including changes in both thinking (p = 0.0001) and behaviour (p = 0.0001), as well as affective response to the delusion (p = 0.0001) The high frequency of religious delusions may indicate a higher tolerance for religious delusions in this community. It is therefore important to educate spiritual leaders on mental illness.

Community Mental Health Journal, 2016

South African Medical Journal, 2012

South African Journal of Psychiatry, 2014

ABSTRACT Background. Clozapine use is known to be associated with significant side-effects, inclu... more ABSTRACT Background. Clozapine use is known to be associated with significant side-effects, including prolongation of the QT-interval, agranulocytosis and metabolic syndrome. However, few data exist on the prevalence of clozapine side-effects in patients of Xhosa descent. Objective. To gather data from Xhosa patients with schizophrenia to establish the prevalence of clozapine side-effects in this population. Methods. Twenty-nine Xhosa patients with schizophrenia (as per the Diagnostic and Statistical Manual of Mental Disorders (DSM-IV-TR)) who had been receiving clozapine treatment for > 1 year on an outpatient basis were selected for inclusion. All patients were participating in a genetics study in the Cape Metropolitan area. The participants were evaluated for the presence of side-effects (tests including an electrocardiogram, white blood cell count (WCC) and fasting blood glucose). Results. The prevalence of metabolic syndrome was 44.8% (95% confidence interval (CI) 26.7 - 62.9) and of undiagnosed diabetes mellitus 13.8% (95% CI 1.24 - 26.34). There was a significant association between metabolic syndrome and body mass index (BMI) (p < 0.01). The mean (SD) WCC was 7.8 x 10(9)/L (2.8), with 3.4% of the subjects having a WCC < 3.5 x 10(9)/L. Sedation (82.8%; 95% CI 69.0 - 96.5), hypersalivation (79.3%; 95% CI 64.6 - 94.1) and constipation (44.8%; 95% CI 26.7 - 62.9) were common. The mean QT-interval was 373.8 (35.9) ms and 10% had a corrected QT-interval > 440 ms. There was an association between the duration of clozapine treatment and QT-interval (with Bazett's correction). Conclusion. The high prevalence of metabolic syndrome and undiagnosed diabetes mellitus in this sample points to a need to monitor glucose levels and BMI on a regular basis. A larger study should be done to accurately quantify the differences in prevalence of side-effects between population groups.

South African Journal of …, 2008

... Am J Psychother 1987; 41: 409-416. 7. Greenberg D, Witztum E, Levy A. Hoarding as a psychiatr... more ... Am J Psychother 1987; 41: 409-416. 7. Greenberg D, Witztum E, Levy A. Hoarding as a psychiatric symptom. J Clin Psychiatry 1990; 51: 417-421. ... 17. Niehaus DJH, Koen L, Muller J, et al. OCD – prevalence in Xhosa speaking schizophrenia patients. ...

In het eindexamenprogramma van de natuurwetenschappelijke vakken op de middelbare school worden e... more In het eindexamenprogramma van de natuurwetenschappelijke vakken op de middelbare school worden een aantal onderzoeksvaardigheden beschreven die leerlingen behoren te beheersen bij het behalen van een diploma (CEVO, 2009). Als natuurkunde docenten in opleiding, ...

BMC Psychiatry, 2008

Background: Severe pressures on beds in psychiatric services have led to the implementation of an... more Background: Severe pressures on beds in psychiatric services have led to the implementation of an early ("crisis") discharge policy in the Western Cape, South Africa. The study examined the effect of this policy and length of hospital stay (LOS) on readmission rates in one psychiatric hospital in South Africa.

European Neuropsychopharmacology, 2015

African journal of psychiatry, 2008

Although the integration of psychiatric services into the community has potentially been benefici... more Although the integration of psychiatric services into the community has potentially been beneficial to many patients, this transition has not been without problems. A major obstacle to establishing successful community-based treatment in South Africa has been that the reduction in number of inpatients beds did not coincide with the development of adequate community resources. This, in combination with our patients' poor socio-economic circumstances, has contributed to a substantial increase in the so-called "revolving door" or high frequency use phenomenon in state psychiatric facilities. Clearly, there is need for a renewed approach to address this problem in our setting. With this in mind the APH in the Western Cape appointed three community treatment teams in January 2007. This publication serves to give an overview of the Stikland Psychiatric Hospital team's experiences in the first 12 months since establishment. To date, we have been confronted by several chal...

West African journal of medicine

Initially the risk of HIV in people with severe mental illness (SMI) was grossly underestimated, ... more Initially the risk of HIV in people with severe mental illness (SMI) was grossly underestimated, but comparisons with the general population have in fact revealed higher infection rates in this particular group. Not only are patients with SMI sexually active but it has also been demonstrated that this group and especially patients with schizophrenia are less knowledgeable about HIV risk behaviours than the general population. Currently no data concerning the participation in and knowledge of HIV/AIDS risk behaviours by South African schizophrenic patients is available. Patients with schizophrenia and a control-group were recruited from community clinics in the Western Cape, South Africa, whereafter 43 from each group were matched (race, age, sex). The patient group was subjected to a structured clinical interview and both groups completed the AIDS Risk Behaviour Assessment (ARBAQ) and Knowledge (ARBKQ) Questionnaires. Comparatively, significant knowledge deficits could be demonstrat...

Schizophrenia Research, 2006

Frontiers in Genetics, 2013

The CYP3A4 enzyme is the most abundant human cytochrome P450 (CYP) and is regarded as the most im... more The CYP3A4 enzyme is the most abundant human cytochrome P450 (CYP) and is regarded as the most important enzyme involved in drug metabolism. Inter-individual and inter-population variability in gene expression and enzyme activity are thought to be influenced, in part, by genetic variation. Although Southern African individuals have been shown to exhibit the highest levels of genetic diversity, they have been under-represented in pharmacogenetic research to date. Therefore, the aim of this study was to identify genetic variation within CYP3A4 in three South African population groups comprising of 29 Khoisan, 65 Xhosa and 65 Mixed Ancestry (MA) individuals. To identify known and novel CYP3A4 variants, 15 individuals were randomly selected from each of the population groups for bi-directional Sanger sequencing of ~600 bp of the 5'-upstream region and all thirteen exons including flanking intronic regions. Genetic variants detected were genotyped in the rest of the cohort. In total, 24 SNPs were detected, including CYP3A4(*)12, CYP3A4(*)15, and the reportedly functional CYP3A4(*)1B promoter polymorphism, as well as two novel non-synonymous variants. These putatively functional variants, p.R162W and p.Q200H, were present in two of the three populations and all three populations, respectively, and in silico analysis predicted that the former would damage the protein product. Furthermore, the three populations were shown to exhibit distinct genetic profiles. These results confirm that South African populations show unique patterns of variation in the genes encoding xenobiotic metabolizing enzymes. This research suggests that population-specific genetic profiles for CYP3A4 and other drug metabolizing genes would be essential to make full use of pharmacogenetics in Southern Africa. Further investigation is needed to determine if the identified genetic variants influence CYP3A4 metabolism phenotype in these populations.