Browsing by Author "Mena, Cristián"
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Item Duration of untreated psychosis and acute remission of negative symptoms in a South American first-episode psychosis cohort.(Wiley Publishing Asia Pty Ltd., 2015) González-Valderrama, Alfonso; Castañeda, Carmen Paz; Mena, Cristián; Undurraga, Juan; Mondaca, Pilar; Yáñez, Matías; Bedregal, Paula; Nachar, RubénAIM: To determine the association between duration of untreated psychosis (DUP) and symptoms remission in a hospitalized first-episode psychosis cohort. METHODS: Inpatients with a first-episode non-affective psychosis were recruited. Subjects were divided into two groups of long and short DUP using a 3-month cut-off point, and this was related to remission at 10 weeks of treatment. Multivariate analyses were performed. RESULTS: Fifty-five inpatients were included. There were no differences in remission rates of positive symptoms. Up to 76.5% of the patients with a short DUP (<3 months) achieved remission of negative symptoms versus 31.6% in the DUP ≥ 3 months group (P = 0.003). After controlling for relevant factors, patients with a shorter DUP were still three times more likely to achieve negative symptoms remission (HR: 3.04, 95% CI 1.2-7.5). CONCLUSIONS: DUP is a prognostic factor that should be considered at an early stage to identify a 'high risk' subgroup of persistent negative symptoms.Item Implementing psychosocial evidence-based practices in mental health: are we moving in the right direction?(2015) González-Valderrama, Alfonso; Mena, Cristián; Undurraga, Juan; Gallardo, Carlos; Mondaca, PilarOne of the main goals of research in health sciences is to provide clinically relevant information aimed at generating effective interventions in the patients’ care. Many ways to bring the new knowledge into daily practice have been implemented: clinical guidelines, reviews in journals, continuing medical education (CME), courses and seminars, easy access to online information, and thers (1). However, there is a gap between evidence-based knowledge and clinical practice in different medical settings.Item The incidence of non-affective psychotic disorders in Chile between 2005 and 2018: results from a national register of over 30 000 cases(2020-08) González-Valderrama, Alfonso; Jongsma, Hannah E.; Mena, Cristián; Castañeda, Carmen Paz; Nachar, Rubén; Undurraga, Juan; Crossley, Nicolás; Aceituno, David; Iruretagoyena, Bárbara; Gallardo, Carlos; Mondaca, Pilar; Monje, Matías; Irarrazaval, Matías; Zavala, Cynthia; Valmaggia, Lucia; Kirkbride, James B.Background. Evidence suggests the incidence of non-affective psychotic disorders (NAPDs) varies across persons and places, but data from the Global South is scarce. We aimed to estimate the treated incidence of NAPD in Chile, and variance by person, place and time. Methods. We used national register data from Chile including all people, 10–65 years, with the first episode of NAPD (International Classification of Diseases, Tenth Revision: F20– F29) between 1 January 2005 and 29 August 2018. Denominators were estimated from Chilean National Census data. Our main outcome was treated incidence of NAPD and age group, sex, calendar year and regional-level population density, multidimensional poverty and latitude were exposures of interest. Results. We identified 32358 NAPD cases [12136 (39.5%) women; median age-at-first- contact: 24 years (interquartile range 18–39 years)] during 171.1 million person-years [crude incidence: 18.9 per 100 000 person-years; 95% confidence interval (CI) 18.7–19.1]. Multilevel Poisson regression identified a strong age–sex interaction in incidence, with rates peaking in men (57.6 per 100 000 person-years; 95% CI 56.0–59.2) and women (29.5 per 100 000 person-years; 95% CI 28.4–30.7) between 15 and 19 years old. Rates also decreased (non-linearly) over time for women, but not men. We observed a non-linear association with multidimensional poverty and latitude, with the highest rates in the poorest regions and those immediately south of Santiago; no association with regional population density was observed. Conclusion. Our findings inform the aetiology of NAPDs, replicating typical associations with age, sex and multidimensional poverty in a Global South context. The absence of asso- ciation with population density suggests this risk may be context-dependent.Item Uso de cannabis en jóvenes hospitalizados por un primer episodio de psicosis: un estudio caso-control(2020) Castañeda, Carmen Paz; Iruretagoyena, Bárbara; Nachar, Rubén; Mancilla, Felipe; Díaz, Camila; Gallardo, Carlos; Mena, Cristián; Ramírez-Mahaluf, Juan Pablo; Undurraga, Juan; González-Valderrama, Alfonso; Crossley, Nicolás A.Background: Cannabis use among young people in Chile has increased significantly in the last years. There is a consistent link between cannabis and psychosis. Aim: To compare cannabis use in patients with a first episode of psychosis and healthy controls. Material and Methods: We included 74 patients aged 20 ± 3 years (78% males) admitted to hospital with a first episode of psychosis and a group of 60 healthy controls aged 23 ± 4 years (63% males). Cannabis consumption was assessed, including age of first time use and length of regular use. Results: Patients with psychosis reported a non-significantly higher frequency of life-time cannabis use. Patients had longer periods of regular cannabis use compared with healthy subjects (Odds ratio [OR] 2.4; 95% confi-dence intervals [CI] 1.14-5.05). Patients also used cannabis for the first time at an earlier age (16 compared with 17 years, p < 0.0). The population attributable fraction for regular cannabis use associated with hospital admissions due to psychosis was 17.7% (95% CI 1.2-45.5%). Conclusions: Cannabis use is related to psychosis in this Chilean group of patients. This relationship is stronger in patients with early exposure to the drug and longer the regular use. One of every five admissions due to psychosis is associated with cannabis consumption. These data should influence cannabis legisla-tion and the public policies currently being discussed in Chile.