The association between reasons for first using cannabis, later pattern of use, and risk of first-episode psychosis: the EU-GEI case-control study.

BACKGROUND: While cannabis use is a well-established risk factor for psychosis, little is known about any association between reasons for first using cannabis (RFUC) and later patterns of use and risk of psychosis. METHODS: We used data from 11 sites of the multicentre European Gene-Environment Interaction (EU-GEI) case-control study. 558 first-episode psychosis patients (FEPp) and 567 population controls who had used cannabis and reported their RFUC.We ran logistic regressions to examine whether RFUC were associated with first-episode psychosis (FEP) case-control status. Path analysis then examined the relationship between RFUC, subsequent patterns of cannabis use, and case-control status. RESULTS: Controls (86.1%) and FEPp (75.63%) were most likely to report 'because of friends' as their most common RFUC. However, 20.1% of FEPp compared to 5.8% of controls reported: 'to feel better' as their RFUC (χ2 = 50.97; p < 0.001). RFUC 'to feel better' was associated with being a FEPp (OR 1.74; 95% CI 1.03-2.95) while RFUC 'with friends' was associated with being a control (OR 0.56; 95% CI 0.37-0.83). The path model indicated an association between RFUC 'to feel better' with heavy cannabis use and with FEPp-control status. CONCLUSIONS: Both FEPp and controls usually started using cannabis with their friends, but more patients than controls had begun to use 'to feel better'. People who reported their reason for first using cannabis to 'feel better' were more likely to progress to heavy use and develop a psychotic disorder than those reporting 'because of friends'.

Clinical practice guideline on pharmacological and psychological management of adult patients with bipolar disorder and comorbid substance use. / Guía de práctica clínica para el tratamiento farmacológico y psicológico de los pacientes adultos con trastorno bipolar y un diagnóstico comórbido de trastorno por uso de sustancias.

This review synthesizes the pharmacological and psychosocial interventions that have been conducted in comorbid bipolar disorder (BD) and substance use disorders (SUDs) while also providing clinical recommendations about which intervention elements are helpful for addressing substance use versus mood symptoms in patients with these co-occurring conditions. The best evidence from randomized controlled trials was used to evaluate treatment options. The strength of recommendations was described using the GRADE approach. Very few of the randomized trials performed so far have provided consistent evidence for the management of both mood symptoms and substance use in patients with a BD. No clinical trials are available for bipolar patients using cannabis. Some treatments have shown benefit for mood symptoms without benefits for alcohol or illicit substance use. Our results suggest that 1) we can (weakly) recommend the use of adjuvant valproate or naltrexone to improve symptoms of alcohol use disorder; 2) Lamotrigine add-on therapy seems to reduce cocaine-related symptoms and is therefore recommended (moderate strength); and 3) Varenicline is (weakly) recommended to improve nicotine abstinence. Integrated group therapy is the most-well validated and efficacious approach on substance use outcomes if substance use is targeted in an initial treatment phase.

Esta revisión resume las intervenciones farmacológicos y psicosociales que se han realizado en trastorno bipolar (TB) y un diagnóstico comórbido de trastorno por uso de sustancias (TUS) y además proporciona recomendaciones clínicas respecto de cuáles elementos de intervención son útiles para hacer frente a los síntomas del uso de sustancias versus los síntomas de estado de ánimo en pacientes con estas afecciones concurrentes. Se utilizó la mejor evidencia de ensayos controlados aleatorizados para evaluar las opciones de tratamiento. La fuerza de las recomendaciones se describió mediante el enfoque GRADE. Muy pocos de los ensayos aleatorizados realizados hasta la fecha han proporcionado evidencia consistente para el manejo tanto de los síntomas de estado de ánimo como del uso de sustancias en pacientes con TB. No hay disponibilidad de ensayos clínicos para pacientes con TB que utilizan el cannabis. Algunos tratamientos han mostrado beneficios para los síntomas de estado de ánimo sin beneficios para el uso de alcohol o sustancias ilícitas. Nuestros resultados sugieren que 1) podemos (débilmente) recomendar el uso de ácido valproico o naltrexona adyuvante para aliviar los síntomas del trastorno por consumo de alcohol; 2) el tratamiento complementario con lamotrigina parece reducir los síntomas relacionados con la cocaína y, por tanto, es recomendable (fuerza moderada); y 3) la vareniclina es recomendable (débilmente) para mejorar la abstinencia de la nicotina. La terapia grupal integrada es el enfoque con más validación y eficacia sobre los resultados en el uso de sustancias cuando este uso es abordado durante la fase inicial de tratamiento.

Clinical practice guideline on pharmacological and psychological management of adult patients with an anxiety disorder and comorbid substance use. / Guía de práctica clínica para el tratamiento farmacológico y psicológico de los pacientes adultos con un trastorno de ansiedad y un diagnóstico comórbido de trastorno por uso de sustancias.

This review synthesizes the pharmacological and psychosocial interventions that have been conducted in comorbid anxiety disorders and SUDs while also providing clinical recommendations about which intervention elements are helpful for addressing substance use versus anxiety symptoms in patients with these co-occurring conditions. The best evidence from randomized controlled trials was used to evaluate treatment options. The strength of recommendations was described using the GRADE approach. Clinical trials are only available for posttraumatic stress disorder (PTSD) and for social anxiety. Concerning the comorbid substance use, all the studies have included patients with alcohol use, none of them have dealt with cocaine, cannabis or nicotine use. Although some treatments have shown benefit for anxiety symptoms without benefits for alcohol or other substance use, only limited pharmacological approaches have been assayed (sertraline, desipramine, paroxetine, buspirone, naltrexone and disulfiram). Our results suggest that 1) we can (weakly) recommend the use of desipramine over paroxetine to alleviate symptoms of anxiety in patients with a PTSD and alcohol use; 2) In these patients, the use of naltrexone to reduce symptoms of anxiety is also recommended (weak strength); and 3) SSRI antidepressants vs placebo can be recommended to reduce alcohol use (weak recommendation). Our review highlights the need for more research in this area and for larger, multisite studies with generalizable samples to provide more definite guidance for clinical practice.

Esta revisión resume las intervenciones farmacológicos y psicosociales que han sido llevadas a cabo en trastornos de ansiedad con un diagnóstico comórbido de trastorno por uso de sustancias y además proporciona recomendaciones clínicas respecto de cuáles elementos de intervención son útiles para hacer frente a los síntomas del uso de sustancias y los síntomas de ansiedad en pacientes con estas afecciones concurrentes. Se utilizó la mejor evidencia de ensayos controlados aleatorizados para evaluar las opciones de tratamiento. La fuerza de las recomendaciones se describió mediante el enfoque GRADE. Hay ensayos clínicos disponibles únicamente para el trastorno por estrés postraumático (TEPT) y para el trastorno de ansiedad. En cuanto al diagnóstico comórbido de trastorno por uso de sustancias, todos los estudios han incluido pacientes con consumo de alcohol, ninguno de ellos ha abordado el consumo de cocaína, cannabis o nicotina. Aunque algunos tratamientos han mostrado beneficios para los síntomas de ansiedad sin beneficios para el consumo de alcohol u otras sustancias, solo se han ensayado enfoques farmacológicos limitados (sertralina, desipramina, paroxetina, buspirona, naltrexona y disulfiram). Nuestros resultados sugieren que 1) podemos (débilmente) recomendar el uso de desipramina sobre la paroxetina para aliviar los síntomas de ansiedad en pacientes con un TEPT y consumo de alcohol; 2) en estos pacientes, el uso de naltrexona para reducir los síntomas de ansiedad es también recomendable (fuerza débil); y 3) se pueden recomendar antidepresivos ISRS frente a placebo para reducir el consumo de alcohol (recomendación débil). Nuestra revisión pone de relieve la necesidad de realizar más investigaciones en esta área y de estudios más grandes, multisitio con muestras generalizables para proporcionar evidencia más definitiva para la práctica clínica.

Clinical practice guideline on pharmacological and psychological management of adult patients with attention deficit and hyperactivity disorder and comorbid substance use. / Guía de práctica clínica para el tratamiento farmacológico y psicológico de los pacientes adultos con trastorno por déficit de atención con hiperactividad y un diagnóstico comórbido de trastorno por uso de sustancias.

Substantial evidence has confirmed the high comorbidity between Attention-Deficit/Hyperactivity Disorder (ADHD) and a substance use disorder (SUD). This review synthesizes the pharmacological and psychosocial interventions conducted in ADHD and SUDs, and provides clinical recommendations using the GRADE approach. Our results suggest: 1) In patients with ADHD and alcohol use, atomoxetine is recommended to reduce ADHD symptoms (weak recommendation) and alcohol craving (weak recommendation). 2) In patients with ADHD and cannabis use disorder, atomoxetine is recommended to improve ADHD symptoms (weak recommendation), not to reduce cannabis use (weak recommendation). 3) In patients with ADHD and cocaine use disorder, methylphenidate is not recommended to improve ADHD symptoms or to reduce cocaine use (weak recommendation). 4) In patients with ADHD and comorbid nicotine use disorder, methylphenidate is recommended to improve ADHD symptoms (weak recommendation). Psychoestimulants, such as methylphenidate or lisdexamfetamine dimesylate, are not recommended to reduce nicotine use (weak recommendation). 5) Regarding patients with ADHD and any SUD, the use of psychostimulants is recommended to improve ADHD symptoms (weak recommendation), not to reduce substance use (weak recommendation) or to improve retention to treatment (strong recommendation). In these patients, the use of atomoxetine is recommended to improve ADHD symptoms (weak recommendation), not to decrease substance use (weak recommendation) or to improve retention to treatment (strong recommendation). Atomoxetine and psychostimulants appear to be safe in patients with any SUD (strong recommendation). Our review suggests the need for more research in this area and for larger, multisite, randomized studies to provide more definite and conclusive evidence.

La evidencia actual confirma la alta comorbilidad entre el trastorno por déficit de atención con hiperactividad (TDAH) y trastorno por uso de sustancias (TUS). Esta revisión resume las intervenciones farmacológicas y psicosociales que se han evaluado en pacientes con TDAH y TUS, y ofrece recomendaciones mediante el enfoque GRADE. Nuestros resultados sugieren: 1) En pacientes con TDAH y trastorno por uso de alcohol, la atomoxetina es recomendable para reducir los síntomas de TDAH (recomendación débil) y el craving de alcohol (recomendación débil). 2) En pacientes con TDAH y trastorno por uso de cannabis, la atomoxetina es recomendable para mejorar los síntomas de TDAH (recomendación débil), no para reducir el uso de cannabis (recomendación débil). 3) En pacientes con TDAH y trastorno por uso de cocaína, el metilfenidato no es recomendable para mejorar los síntomas de TDAH o para reducir el uso de cocaína (recomendación débil). 4) En pacientes con TDAH y trastorno por uso de nicotina, es recomendable el metilfenidato para mejorar los síntomas de TDAH (recomendación débil). Los psicoestimulantes, como metilfenidato o lisdexanfetamina, no son recomendables para reducir el uso de nicotina (recomendación débil). 5) Respecto de los pacientes con TDAH y cualquier TUS, el uso de los psicoestimulantes es recomendable para mejorar los síntomas de TDAH (recomendación débil), no para reducir el uso de sustancias (recomendación débil) o para mejorar la retención del tratamiento (recomendación fuerte). En estos pacientes, el uso de atomexetina es recomendable para mejorar los síntomas de TDAH (recomendación débil), no para reducir el uso de sustancias (recomendación débil) o para mejorar la retención del tratamiento (recomendación fuerte). La atomoxetina y los psicoestimulantes parecen ser seguros en pacientes con cualquier TUS (recomendación fuerte). Nuestra revisión sugiere la necesidad de realizar más investigaciones en esta área y de estudios aleatorizados, multicéntricos y de mayor tamaño muestral para proporcionar más evidencia definitiva y concluyente.

Clinical practice guideline on pharmacological and psychological management of adult patients with schizophrenia spectrum disorders and a comorbid substance use. / Guía de práctica clínica para el tratamiento farmacológico y psicológico de los pacientes adultos con un trastorno del espectro esquizofrénico y un diagnóstico comórbido de trastorno por uso de sustancias.

Although correct diagnosis and management of patients with schizophrenia and a comorbid substance use disorder (SUD) would determine a decrease in morbidity and mortality in these patients, development of efficient therapeutic strategies is still pending. We present recommendations on the pharmacological and psychological management of these patients following the 'PICO' structure (Patient-Intervention-Comparison-Outcomes). Evaluation of the quality of studies and summary of the evidence for each question was performed following the recommendations of the GRADE (Grading of Recommendations, Assessment, Development and Evaluation) working group. Our results suggest: 1) In patients with schizophrenia and cannabis use disorder, it is not possible to recommend one antipsychotic drug over another (between olanzapine, risperidone or haloperidol) for improving psychotic symptoms, reducing cannabis use, or improving pragmatic variables (weak recommendation). Clozapine cannot be recommended to reduce cannabis use (weak recommendation). 2) In patients with schizophrenia and cocaine use disorder we recommend haloperidol over olanzapine to reduce craving (moderate recommendation), and olanzapine over haloperidol to improve motor side effects in these patients (moderate recommendation). 3) In patients with schizophrenia and alcohol use disorder while naltrexone is recommended to reduce alcohol use (in terms of reducing alcohol craving) (weak recommendation), there is insufficient evidence to make any recommendation on the use of adjuvant acamprosate (weak recommendation). 4) In patients with schizophrenia and nicotine use disorder, adjuvant bupropion and varenicline are recommended for reducing nicotine use and nicotine abstinence (strong/moderate recommendation). 5) In patients with schizophrenia and polydrug use disorder, second-generation over first-generation antipsychotic drugs and olanzapine over other second-generation antipsychotics are recommended to improve psychotic symptoms (moderate/weak recommendation).

Aunque el correcto diagnóstico y manejo de los pacientes con esquizofrenia y un diagnóstico comórbido de trastorno por uso de sustancias (TUS) determinaría una disminución de la morbilidad y mortalidad en estos pacientes, el desarrollo de estrategias terapéuticas eficientes es todavía una asignatura pendiente. Presentamos recomendaciones sobre el manejo farmacológico y psicológico de estos pacientes siguiendo la estructura PICO (Paciente-Intervención-Comparación-Outcome/resultados). Realizamos una evaluación de la calidad de los estudios y un resumen de la evidencia para cada pregunta siguiendo las recomendaciones del grupo de trabajo GRADE («Grading of Recommendations, Assessment, Development and Evaluation¼). Nuestros resultados sugieren: 1) En pacientes con esquizofrenia y trastorno por consumo de cannabis, no es posible recomendar un fármaco antipsicótico sobre otro (entre olanzapina, risperidona o haloperidol) para mejorar los síntomas psicóticos, reducir el consumo de cannabis o mejorar las variables pragmáticas (recomendación débil). No se puede recomendar la clozapina para reducir el consumo de cannabis (recomendación débil). 2) En pacientes con esquizofrenia y trastorno por consumo de cocaína, recomendamos haloperidol sobre olanzapina para reducir el craving (recomendación moderada) y olanzapina sobre haloperidol para mejorar los efectos secundarios motores en estos pacientes (recomendación moderada). 3) En pacientes con esquizofrenia y trastorno por consumo de alcohol, mientras que se recomienda naltrexona para reducir el consumo de alcohol (en términos de reducción del craving de alcohol) (recomendación débil), no hay evidencia suficiente para hacer ninguna recomendación sobre el uso de acamprosato como adyuvante (recomendación débil). 4) En pacientes con esquizofrenia y trastorno por consumo de nicotina, se recomiendan bupropión y vareniclina adyuvantes para reducir el consumo y la abstinencia de nicotina (recomendación fuerte/moderada). 5) En pacientes con esquizofrenia y trastorno por policonsumo, se recomiendan antipsicóticos de segunda generación sobre los de primera generación y olanzapina sobre otros antipsicóticos de segunda generación para mejorar los síntomas psicóticos (recomendación moderada/débil).

Clinical practice guideline on pharmacological and psychological management of adult patients with depression and a comorbid substance use disorder. / Guía de práctica clínica para el tratamiento farmacológico y psicológico de los pacientes adultos con depresión y un diagnóstico comórbido de trastorno por uso de sustancias.

Co-occurrence of depression and a substance use disorder (SUD) in patients who present dual diagnoses has been long recognized as an important consideration in clinical practice. This review synthesizes the evidence of pharmacological and psychosocial interventions for comorbid depressive disorders and SUDs while providing clinical recommendations about the best interventions to address these patients. The best evidence from randomized controlled trials was used to evaluate treatment options. The strength of recommendations was described using the GRADE approach. Our results suggest that 1) In patients with depression and alcohol consumption, the administration of non-selective serotonin reuptake inhibitor (SSRI) antidepressants instead of SSRI is recommended for improvement of depressive symptoms (strong recommendation). Neither SSRI (strong recommendation) nor non-SSRI (weak recommendation) antidepressants are recommended for reduction in alcohol consumption. 2) In patients with depression and cannabis use, the use of venlafaxine is not recommended (weak recommendation). 3) In patients with depression and cocaine consumption, the use of SSRI antidepressants for improving depressive symptoms (weak recommendation) or to reduce cocaine use is not recommended (strong recommendation). The use of non-SSRI antidepressants is only recommended for improving depressive symptoms (strong recommendation). 4) The administration of bupropion to reduce nicotine consumption is not recommended (strong recommendation). 5) Regarding psychological treatment, in patients with depression and co-occurring alcohol disorder, both pharmacotherapy and cognitive behavioural therapy have positive effects on internalizing symptoms and in reducing alcohol consumption (weak recommendation). Our review suggests the need for more research in this area and for larger, multisite, randomized studies to provide more definite evidence.

La concurrencia de depresión y un trastorno por uso de sustancias (TUS) en pacientes que presentan patología dual ha sido reconocida desde hace mucho tiempo como una consideración importante en la práctica clínica. Esta revisión sintetiza la evidencia de intervenciones farmacológicas y psicosociales para trastornos comórbidos de depresión y uso de sustancias y además proporciona recomendaciones clínicas respecto de las mejores intervenciones para tratar a estos pacientes. Se utilizó la mejor evidencia de ensayos controlados aleatorizados para evaluar las opciones de tratamiento. La fuerza de las recomendaciones se describió mediante el enfoque GRADE. Nuestros resultados sugieren que: 1) en pacientes con depresión y consumo de alcohol, se recomienda la administración de antidepresivos inhibidores de la recaptación de serotonina (ISRS) no selectivos en lugar de los ISRS para mejorar los síntomas depresivos (recomendación fuerte). No se recomiendan antidepresivos ISRS (recomendación fuerte) ni antidepresivos no ISRS (recomendación débil) para reducir el consumo de alcohol; 2) en pacientes con depresión y consumo de cannabis, no se recomienda el uso de venlafaxina (recomendación débil); 3) en pacientes con depresión y consumo de cocaína, no se recomienda el uso de antidepresivos ISRS para mejorar los síntomas depresivos (recomendación débil) o para reducir el consumo de cocaína (recomendación fuerte). El uso de antidepresivos no ISRS solo se recomienda para mejorar los síntomas depresivos (recomendación fuerte); 4) no se recomienda la administración de bupropión para reducir el consumo de nicotina (recomendación fuerte), y 5) en cuanto al tratamiento psicológico, en pacientes con depresión y trastorno de alcohol concurrente, tanto la farmacoterapia como la terapia cognitivo-conductual tienen efectos positivos en la internalización de los síntomas y en la reducción del consumo de alcohol (recomendación débil). Nuestra revisión sugiere la necesidad de realizar más investigaciones en esta área y de estudios aleatorizados, multisitio y más grandes para proporcionar más evidencia definitiva.

A polygenic approach to the association between smoking and schizophrenia.

Smoking prevalence in schizophrenia is considerably larger than in general population, playing an important role in early mortality. We compared the polygenic contribution to smoking in schizophrenic patients and controls to assess if genetic factors may explain the different prevalence. Polygenic risk scores (PRSs) for smoking initiation and four genetically correlated traits were calculated in 1108 schizophrenic patients (64.4% smokers) and 1584 controls (31.1% smokers). PRSs for smoking initiation, educational attainment, body mass index and age at first birth were associated with smoking in patients and controls, explaining a similar percentage of variance in both groups. Attention-deficit hyperactivity disorder (ADHD) PRS was associated with smoking only in schizophrenia. This association remained significant after adjustment by psychiatric cross-disorder PRS. A PRS combining all the traits was more explanative than smoking initiation PRS alone, indicating that genetic susceptibility to the other traits plays an additional role in smoking behaviour. Smoking initiation PRS was also associated with schizophrenia in the whole sample, but the significance was lost after adjustment for smoking status. This same pattern was observed in the analysis of specific SNPs at the CHRNA5-CHRNA3-CHRNB4 cluster associated with both traits. Overall, the results indicate that the same genetic factors are involved in smoking susceptibility in schizophrenia and in general population and are compatible with smoking acting, directly or indirectly, as a risk factor for schizophrenia that contributes to the high prevalence of smoking in these patients. The contrasting results for ADHD PRS may be related to higher ADHD symptomatology in schizophrenic patients.

Relationships between substance abuse/dependence and psychiatric disorders based on polygenic scores.

Genetic susceptibility to substance use disorders (SUDs) is partially shared between substances. Heritability of any substance dependence, estimated as 54%, is partly explained by additive effects of common variants. Comorbidity between SUDs and other psychiatric disorders is frequent. The present study aims to analyze the additive role of common variants in this comorbidity using polygenic scores (PGSs) based on genome-wide association study discovery samples of schizophrenia (SCZ), bipolar disorder, attention-deficit/hyperactivity disorder, autism spectrum disorder, major depressive disorder and anxiety disorders, available from large consortia. PGSs were calculated for 534 patients meeting DSM-IV criteria for dependence of a substance and abuse/dependence of another substance between alcohol, tobacco, cannabis, cocaine, opiates, hypnotics, stimulants, hallucinogens and solvents; and 587 blood donors from the same population, Iberians from Galicia, as controls. Significance of the PGS and percentage of variance explained were calculated by logistic regression. Using discovery samples of similar size, significant associations with SUDs were detected for SCZ PGS. SCZ PGS explained more variance in SUDs than in most psychiatric disorders. Cross-disorder PGS based on five psychiatric disorders was significant after adjustment for the effect of SCZ PGS. SCZ PGS was significantly higher in women than in men abusing alcohol. Our findings indicate that SUDs share genetic susceptibility with SCZ to a greater extent than with other psychiatric disorders, including externalizing disorders such as attention-deficit/hyperactivity disorder. Women have lower probability to develop substance abuse/dependence than men at similar PGS probably because of a higher social pressure against excessive drug use in women.

Tobacco and cognitive performance in schizophrenia patients: the design of the COGNICO study. / Tabaco y rendimiento cognitivo en pacientes con esquizofrenia: diseño del estudio COGNICO.

People with schizophrenia constitute a substantial part of the people who still smoke. Regarding cognitive performance, the self-medication hypothesis states that patients smoke to improve their cognitive deficits based on the stimulating effects of nicotine. The aim of this paper is to describe in detail the methodology used in the COGNICO study. A quasi-experimental, observational, prospective, multicenter study with follow-ups over 18 months was conducted in three cities in northern Spain (Oviedo, Ourense and Santiago de Compostela). A total of 81 outpatient smokers with schizophrenia were recruited with a mean age 43.35 years (SD = 8.83), 72.8% of them male. They were assigned to 3 groups: a) control group (smokers); b) patients who quit smoking using nicotine patches; c) patients who quit smoking with Varenicline. The MATRICS neuropsychological battery was applied as a primary measure. In addition, a comprehensive assessment of patients was performed, including the number of cigarettes per day, physical and psychological dependence on nicotine and CO expired. Clinical evaluation (PANSS, HDRS, CGI, C-SSRS), anthropometric measurements and vital signs assessment was also performed. The aim is to identify the relationship between the pattern of tobacco use and cognitive performance by comparing scores on the neuropsychological battery MATRICS during the follow-up periods (3, 6, 12 and 18months). The importance of this study lies in addressing a topical issue often ignored by clinicians: the unacceptably high rates of tobacco use in patients with severe mental disorders.

Las personas con esquizofrenia constituyen una parte sustancial de las personas que todavía fuman. La hipótesis de la automedicación en relación al rendimiento cognitivo mantiene que los pacientes fuman para mejorar su déficit cognitivo basándose en los efectos estimulantes de la nicotina. El objetivo de este artículo es describir la metodología del estudio COGNICO. Estudio cuasiexperimental, observacional, prospectivo, multicéntrico y  con seguimiento a 3, 6, 12 y 18 meses. Fue llevado a cabo en tres ciudades del norte de España (Oviedo, Ourense y Santiago de Compostela). Se reclutaron 81pacientes con esquizofrenia fumadores (edad media de 43,35 años (DT=8,83). 72,8% varones). Se asignaron a 3 grupos: a) control: pacientes fumadores; b) pacientes que dejan de fumar mediante parches de nicotina; c) pacientes que dejan de fumar mediante vareniclina. Como medida primaria se aplicó la batería neuropsicológica MATRICS. Además, se llevó a cabo una evaluación comprehensiva de los pacientes, que incluía  el número de cigarrillos por día, la dependencia física y psicológica a la nicotina y el CO expirado. También se realizó una evaluación clínica general (PANSS, HDRS, ICG, C-SSRS) así como un seguimiento de las medidas antropométricas y los signos vitales. Se pretende  identificar la relación entre el patrón de consumo de tabaco y el rendimiento cognitivo mediante la comparación de las puntuaciones en la batería neuropsicológica MATRICS durante los períodos de seguimiento.

Interaction between COMT haplotypes and cannabis in schizophrenia: a case-only study in two samples from Spain.

Cannabis use is one of the environmental factors with more solid evidence contributing to schizophrenia risk, especially in genetically susceptible individuals. One of the genes that may interact with cannabis is COMT, although available data are scarce. Here, we present a case-only study of the putative COMT-cannabis interaction in schizophrenia. Two Spanish samples from Santiago de Compostela and Valencia were screened for cannabis use. One hundred and fifty five individuals from a total of 748 patients were identified as cannabis users. Five SNPs in COMT, defining three common functional haplotypes with different enzymatic activities, were genotyped and analyzed for association at the SNP, haplotype and genotype levels. An association was detected between cannabis use and low activity variants (P<0.01) in the joint analysis and results were consistent between the two samples. Schizophrenic subjects homozygous for the Met allele at rs4680 doubled the probability of lifetime prevalence of cannabis use in comparison to Val homozygous (Mantel-Haenszel OR=2.07, 95% CI: 1.27-3.26, P=0.0031, in the combined sample). These data are in contrast to those from Caspi et al. (Biol. Psychiatry 57 (2005)1117-1127) who found association between schizophrenia/schizophreniform disorder and homozygosity at the high activity Val variant of rs4680. The results of our study are discussed in the context of previous findings, suggesting the involvement of COMT polymorphisms in the association between cannabis use and schizophrenia as well as the existence of additional factors mediating this association. However, further research is needed to confirm the COMT-cannabis interaction.

Testing the antagonistic pleiotropy model of schizophrenia susceptibility by analysis of DAOA, PPP1R1B, and APOL1 genes.

Schizophrenia is a common disease associated with reduced fertility. Therefore, the existence of common susceptibility alleles not removed by natural selection may be considered an evolutionary paradox. The antagonistic pleiotropy model, proposed to explain this paradox, states that an allele may be common because of its overall selective advantage, in spite of deleterious effects on specific traits. Recent work on DAOA, PPP1R1B, and APOL1 suggests that these genes present common alleles associated to increase risk of schizophrenia but conferring an overall selective advantage, related to better cognitive performance (DAOA and PPP1R1B) or protection against pathogens (APOL1). To test if these genes fit the antagonistic pleiotropy model, we searched for recent natural selection at these loci applying the long-range haplotype test on data from the HapMap Project; and performed case-control association analysis in a well-powered sample, including 301 schizophrenic patients and 604 controls from Spain. For DAOA and PPP1R1B, we genotyped the Single-nucleotide polymorphisms (SNPs) needed to replicate previous associations, while for APOL1, we genotyped 15 tagSNPs, and seven putative functional SNPs. We did not detect evidence of recent natural selection. Furthermore, we did not find significant associations. Thus, these genes do not fit the antagonistic pleiotropy model.

Platelet monoamine oxidase activity in obsessive-compulsive disorder.

Response to SSRIs suggests the implication of the serotonergic system in obsessive-compulsive disorder (OCD). However, biological studies on serotonergic function in OCD have yielded contradictory results. Platelet monoamine oxidase (MAO) activity has been proposed as an index of cerebral serotonin activity. The aim of this study was to examine platelet MAO activity in 29 OCD patients and 29 healthy controls matched by age, sex and tobacco use. We also explored the relationship between platelet MAO activity and aggressive obsessions in OCD patients. There were no differences in platelet MAO activity between OCD patients and healthy controls. We found a significant correlation between platelet MAO activity and Y-BOCS scores in the group of patients with Y-BOCS scores >15. OCD patients with aggressive obsessions had significantly lower levels of platelet MAO activity than patients without aggressive obsessions. Our results suggest that platelet MAO activity may be a marker of OCD severity, and that low platelet MAO activity may be associated with aggressive obsessions in OCD patients.