Mohd Azhar Mohd Yasin

The pathway followed by psychotic patients to a tertiary health center in a developing country: A comparison with patients with epilepsy

The objective of this study was to describe and compare the pathways followed by Malay patients with psychoses (schizophrenia and schizophreniform disorder) and Malay patients with epilepsy to a tertiary health center in the northeastern area of peninsular Malaysia. There were 60 patients in each group. The most popular pathway for both groups was first contact with traditional or alternative healers. Consultation with Malay traditional healers (bomohs) and/or homeopathic practitioners (44.2%) was significantly higher for psychotic patients (61.7%) than for patients with epilepsy (26.7%) (chi(2)(2)=15.609, P<0.001). Direct access (24.2%) was the second most popular pathway and almost equally followed by both groups of patients. The third and last pathway was initial contact with private general practitioners and government doctors, respectively. Patients with epilepsy dominated the last two pathways. The treatment delay (TD) was significantly longer in epileptic than psychotic patients regardless of their visit to a bomoh and/or homeopathic practitioner (P<0001) or not (p<0.01). The socioeconomic status of psychotic patients also was significantly better than people with epilepsy (chi(2)=9.957, chi(2)(4), p=0.041).

Review on EEG and ERP predictive biomarkers for major depressive disorder

Abstract The selection of suitable antidepressants for Major Depressive Disorder (MDD) has been challenging and is mainly based on subjective assessments that include minimal scientific evidence. Objective measures that are extracted from neuroimaging modalities such as electroencephalograms (EEGs) could be a potential solution to this problem. This approach is achieved by the successful prediction of antidepressant treatment efficacy early in the patients care. EEG-based relevant research studies have shown promising results. These studies are based on derived measures from EEG and event-related potentials (ERPs), which are called neurophysiological predictive biomarkers for MDD. This paper seeks to provide a detailed review on such research studies along with their possible limitations. In addition, this paper provides a comparison of these methods based on EEG/ERP common datasets from MDD and healthy controls. This paper also proposes recommendations to improve these methods, e.g., EEG integration with other modalities such as functional magnetic resonance imaging (fMRI) and magnetoencephalograms (MEG), to achieve better evidence of the efficacy than EEG alone, to eventually improve the treatment selection process.

Comparison of Pain Tolerance between Opioid Dependent Patients on Methadone Maintenance Therapy (MMT) and Opioid Naive Individuals.

PURPOSE This study compared pain sensitivity among opioid dependent patients on methadone maintenance therapy (MMT) and opioid naive subjects. METHODS The three hundred participants comprised 152 opioid naive subjects and 148 opioid dependent patients. Opioid naive subjects had not taken any opioids including morphine and methadone to their best knowledge and were presumed so after two consecutive negative urine screenings for drugs. All opioid dependent patients were stabilized in treatment, defined as having been enrolled in the program for more than one month with no change of methadone dosage over the past one month. Excluded from the study were individuals with chronic or ongoing acute pain and individuals with a history of analgesics ingestion within 3 d before the cold pressor test (CPT). Pain tolerance to CPT was evaluated at 0 h, and at 2, 4, 8, 12, and 24 h post-methadone dose. RESULTS Patients exhibited a significantly shorter mean pain tolerance time of 34.17 s (95% CI 24.86, 43.49) versus 61.36 (52.23, 70.48) [p < 0.001] compared with opioid naive subjects. Time-dependent mean pain tolerance was also significantly different when naive subjects were compared to patients (p = 0.016). CONCLUSIONS This study revealed hyperalgesia amongst patients on MMT, as manifested by their quicker hand withdrawal. The complaints of pain in this population should not be underestimated and the pain should be evaluated seriously and managed aggressively.

Emerging Drug Use Trends in Kelantan, Malaysia

ABSTRACT The primarily rural and agrarian Kelantan province of Malaysia has high rates of drug use and is characterized by unique sociocultural factors. Combining qualitative and ethnographic methods, we investigated drug use and treatment needs of people who use drugs (PWUD) in rural areas of Kelantan. In February 2014, field visits, participant observation, and focus group discussions (FGDs) with 27 active PWUD were conducted in rural areas surrounding the capital city of Kelantan. The findings indicate a high prevalence of opiate and amphetamine type stimulants (ATS) use in these areas. FGD participants reported initiating drug use at early ages due to peer influences, to relieve boredom, to cope with problems, and a high saturation of villages with other PWUD was reported as a major contributor to their own continued drug use. They reported a trend of drug use initiation at younger ages and increased drug use among females. Participants were interested in treatment; however, their limited knowledge about treatment options and perceived limited availability of services were barriers to treatment seeking. Easy access to drugs, primarily from Thailand and facilitated by the use of mobile phones, resulted in an expanding prevalence of drug use that underscores the need to bolster education and prevention efforts and accessibility of treatment services in Kelantan.

Abcb1 Polymorphisms and Cold Pressor Pain Responses: Opioid-dependent Patients on Methadone Maintenance Therapy.

Background Methadone is a substrate of the P-glycoprotein efflux transporter, which is encoded by ABCB1 (MDR1), and thus, ABCB1 polymorphisms may influence the transport of methadone at the blood–brain barrier, affecting its adverse effects. Objectives This study investigated the association between ABCB1 polymorphisms and cold pressor pain responses among opioid-dependent patients on methadone maintenance therapy (MMT). Methods Malay male opioid-dependent patients receiving MMT (n = 148) were recruited. Cold pressor pain responses (pain threshold, pain tolerance, and pain intensity) were measured at 0, 2, 4, 8, 12, and 24 hours post-methadone dose. DNA was extracted from whole blood and genotyped for ABCB1 polymorphisms including 1236C>T (rs1128503), 2677G>T/A (rs2032582), and 3435C>T (rs1045642) using the allelic discrimination real-time polymerase chain reaction. Repeated-measure analysis of variance between-group analysis was used to compare the three cold pressor pain responses and ABCB1 polymorphisms (1236C>T, 2677G>T/A, and 3435C>T) according to genotypes and allelic additive models, genotype dominant and recessive models, haplotypes, and diplotypes. Results Patients with 2677 GG or 2677G allele had the lowest pain threshold compared with 2677G>T/A genotypes or alleles (p = .007 and .002, respectively). Haplotype analysis showed a significant association between ABCB1 haplotypes and pain threshold (p = .02). Patients with 2677G allele had the lowest pain tolerance compared to those with 2677T and 2677A alleles (2677G < 2677T < 2677A allele carriers; p = .05). In terms of pain intensity scores, patients with 2677 GG or 2677G allele had the highest scores compared to other 2677G>T/A genotypes or alleles (p = .04 and .008, respectively). Haplotype analysis revealed a significant difference between patients with CGC haplotype and those without this haplotype (p = .02). Discussion To the best of our knowledge, this study provides the first evidence that ABCB1 polymorphisms are associated with cold pressor pain responses among Malay male patients with opioid dependence on MMT. The results may provide an initial prediction on heightened pain sensitivity or hyperalgesia for individuals who are carriers of the ABCB1 polymorphisms.Methadone is a substrate of the P-glycoprotein efflux transporter, which is encoded by ABCB1 (MDR1), and thus, ABCB1 polymorphisms may influence the transport of methadone at the blood–brain barrier, affecting its adverse effects. This study investigated the association between ABCB1 polymorphisms and cold pressor pain responses among opioid-dependent patients on methadone maintenance therapy (MMT). Malay male opioid-dependent patients receiving MMT (n = 148) were recruited. Cold pressor pain responses (pain threshold, pain tolerance, and pain intensity) were measured at 0, 2, 4, 8, 12, and 24 hours post-methadone dose. DNA was extracted from whole blood and genotyped for ABCB1 polymorphisms including 1236C>T (rs1128503), 2677G>T/A (rs2032582), and 3435C>T (rs1045642) using the allelic discrimination real-time polymerase chain reaction. Repeated-measure analysis of variance between-group analysis was used to compare the three cold pressor pain responses and ABCB1 polymorphisms (1236C>T, 2677G>T/A, and 3435C>T) according to genotypes and allelic additive models, genotype dominant and recessive models, haplotypes, and diplotypes. Patients with 2677 GG or 2677G allele had the lowest pain threshold compared with 2677G>T/A genotypes or alleles (p = .007 and .002, respectively). Haplotype analysis showed a significant association between ABCB1 haplotypes and pain threshold (p = .02). Patients with 2677G allele had the lowest pain tolerance compared to those with 2677T and 2677A alleles (2677G T/A genotypes or alleles (p = .04 and .008, respectively). Haplotype analysis revealed a significant difference between patients with CGC haplotype and those without this haplotype (p = .02). To the best of our knowledge, this study provides the first evidence that ABCB1 polymorphisms are associated with cold pressor pain responses among Malay male patients with opioid dependence on MMT. The results may provide an initial prediction on heightened pain sensitivity or hyperalgesia for individuals who are carriers of the ABCB1 polymorphisms.

Relationship between CYP2B6*6 and cold pressor pain sensitivity in opioid dependent patients on methadone maintenance therapy (MMT)

BACKGROUND CYP2B6 polymorphisms contribute to inter-individual variations in pharmacokinetics of methadone. Increased pain sensitivity is frequently reported by opioid dependent patients on methadone maintenance therapy (MMT). It is possible, therefore, that genetic polymorphisms in CYP2B6, which affects the metabolism of methadone, influence pain sensitivity among patients on MMT. This study investigated CYP2B6 polymorphisms and pain sensitivity in this group. METHODS The cold pressor pain responses of 148 opioid dependent patients receiving MMT were evaluated using the cold pressor test (CPT). DNA was extracted from whole blood and subjected to polymerase chain reaction (PCR)-genotyping. RESULTS Of the 148 subjects, 77 (52.0%) were carriers of CYP2B6*6 allele. CYP2B6*6 allele carriers had shorter cold pain threshold and pain tolerance times than non-carriers of CYP2B6*6 allele (21.05s vs 33.69s, p=0.036 and 27.15s vs 44.51s, p=0.020, respectively). Pain intensity scores of the CYP2B6*6 allele carriers was 67.55, whereas that of the CYP2B6*6 allele non-carriers was 64.86 (p=0.352). CONCLUSION Our study indicates that the CYP2B6*6 allele is associated with a lower pain threshold and lower pain tolerance among males with opioid dependence on MMT. The CYP2B6*6 allele may provide a mechanistic explanation for clinical observations of heightened pain sensitivity among opioid dependent patients receiving MMT.

Relationship between ABCB1 polymorphisms and serum methadone concentration in patients undergoing methadone maintenance therapy (MMT)

ABSTRACT Background: Methadone is a substrate of the permeability glycoprotein (P-gp) efflux transporter, which is encoded by the ABCB1 (MDR1) gene. Large interindividual variability in serum methadone levels for therapeutic response has been reported. Genetic variations in ABCB1 gene may be responsible for the variability in observed methadone concentrations. Objective: This study investigated the associations of ABCB1 polymorphisms and serum methadone concentration over the 24-hour dosing interval in opioid-dependent patients on methadone maintenance therapy (MMT). Methods: One hundred and forty-eight male opioid-dependent patients receiving MMT were recruited. Genomic deoxyribonucleic acid (DNA) was extracted from whole blood and genotyped for ABCB1 polymorphisms [i.e. 1236C>T (dbSNP rs1128503), 2677G>T/A (dbSNP rs2032582), and 3435C>T (dbSNP rs1045642)] using the allelic discrimination real-time polymerase chain reaction (PCR). Blood samples were collected at 0, 0.5, 1, 2, 4, 8, 12, and 24 hours after the dose. Serum methadone concentrations were measured using the Methadone ELISA Kit. Results: Our results revealed an association of CGC/TTT diplotype (1236C>T, 2677G>T/A, and 3435C>T) with dose-adjusted serum methadone concentration over the 24-hour dosing interval. Patients with CGC/TTT diplotype had 32.9% higher dose-adjusted serum methadone concentration over the 24-hour dosing interval when compared with those without the diplotype [mean (SD) = 8.12 (0.84) and 6.11 (0.41) ng ml−1 mg−1, respectively; p = 0.033]. Conclusion: There was an association between the CGC/TTT diplotype of ABCB1 polymorphisms and serum methadone concentration over the 24-hour dosing interval among patients on MMT. Genotyping of ABCB1 among opioid-dependent patients on MMT may help individualize and optimize methadone substitution treatment.

Early Initiation of Amphetamine-Type Stimulants (ATS) Use Associated with Lowered Cognitive Performance among Individuals with Co-Occurring Opioid and ATS Use Disorders in Malaysia

ABSTRACT Amphetamine-type stimulants (ATS) use is increasingly prevalent in Malaysia, including among individuals who also use opioids. We evaluated cognitive functioning profiles among individuals with co-occurring opioid and ATS dependence and their lifetime patterns of drug use. Participants (N = 50) enrolling in a clinical trial of buprenorphine/naloxone treatment with or without atomoxetine completed the Raven’s Standard Progressive Matrices, Rey-Osterrieth Complex Figure Test, Digit Span, Trail Making and Symbol Digit Substitution tasks. Multidimensional scaling and a K-means cluster analyses were conducted to classify participants into lower versus higher cognitive performance groups. Subsequently, analyses of variance procedures were conducted to evaluate between group differences on drug use history and demographics. Two clusters of individuals with distinct profiles of cognitive performance were identified. The age of ATS use initiation, controlling for the overall duration of drug use, was significantly earlier in the lower than in the higher cognitive performance cluster: 20.9 (95% CI: 18.0–23.8) versus 25.2 (95% CI: 22.4–28.0, p = 0.038). While adverse effects of ATS use on cognitive functioning can be particularly pronounced with younger age, potentially related to greater vulnerability of the developing brain to stimulant and/or neurotoxic effects of these drugs, the current study findings cannot preclude lowered cognitive performance before initiation of ATS use.

A Study to Investigate Different EEG Reference Choices in Diagnosing Major Depressive Disorder

Choice of an electroencephalogram (EEG) reference is a critical issue during measurement of brain activity. An appropriate reference may improve efficiency during diagnosis of psychiatric conditions, e.g., major depressive disorder (MDD). In literature, various EEG references have been proposed, however, none of them is considered as gold-standard [1]. Therefore, this study aims to evaluate 3 EEG references including infinity reference (IR), average reference (AR) and link-ear (LE) reference based on EEG data acquired from 2 groups: the MDD patients and healthy subjects as controls. The experimental EEG data acquisition involved 2 physiological conditions: eyes closed (EC) and eyes open (EO). Originally, the data were recorded with LE reference and re-referenced to AR and IR. EEG features such as the inter-hemispheric coherences, inter-hemispheric asymmetries, and different frequency bands powers were computed. These EEG features were used as input data to train and test the logistic regression (LR) classifier and the linear kernel support vector machine (SVM). Finally, the results were presented as classification accuracies, sensitivities, and specificities while discriminating the MDD patients from a potential population of healthy controls. According to the results, AR has provided the maximum classification efficiencies for coherence and power based features. The case of asymmetry, IR and LE performed better than AR. The study concluded that the reference selection should include factors such as underlying EEG data, computed features and type of assessment performed.

Detrended fluctuation analysis for major depressive disorder

Clinical utility of Electroencephalography (EEG) based diagnostic studies is less clear for major depressive disorder (MDD). In this paper, a novel machine learning (ML) scheme was presented to discriminate the MDD patients and healthy controls. The proposed method inherently involved feature extraction, selection, classification and validation. The EEG data acquisition involved eyes closed (EC) and eyes open (EO) conditions. At feature extraction stage, the de-trended fluctuation analysis (DFA) was performed, based on the EEG data, to achieve scaling exponents. The DFA was performed to analyzes the presence or absence of long-range temporal correlations (LRTC) in the recorded EEG data. The scaling exponents were used as input features to our proposed system. At feature selection stage, 3 different techniques were used for comparison purposes. Logistic regression (LR) classifier was employed. The method was validated by a 10-fold cross-validation. As results, we have observed that the effect of 3 different reference montages on the computed features. The proposed method employed 3 different types of feature selection techniques for comparison purposes as well. The results show that the DFA analysis performed better in LE data compared with the IR and AR data. In addition, during Wilcoxon ranking, the AR performed better than LE and IR. Based on the results, it was concluded that the DFA provided useful information to discriminate the MDD patients and with further validation can be employed in clinics for diagnosis of MDD.