You will be shown an abstract from a biomedical research paper. Given this abstract, your task is to extract all unique entities of the following types: ["Chemical"].

Please return the output as a JSON object of the format: {"Chemical": ["Arsenic", ...]}. The keys should be entity types and values should be lists of extracted entities belonging to the corresponding type. If you cannot find entities belonging to a specific type, the value should be [].

Only output the JSON object and do not include any additional text.

Abstract:

Psychologic Disorders and Statin Use: A Propensity Score-Matched Analysis. STUDY OBJECTIVE: To evaluate the association between statin therapy and the risk of psychologic disorders including schizophrenia, psychosis, major depression, and bipolar disorder in a military population. DESIGN: Retrospective, observational, population-based, propensity score-matched, cohort study. SETTING: Database of a patient population enrolled in the San Antonio Military Multi-Market Area as Tricare Prime or Plus. PATIENTS: Medical records were reviewed from 46,249 patients aged 30-85 years who were continuously enrolled in the San Antonio Military Multi-Market Area as Tricare Prime or Plus from October 1, 2003-March 1, 2010. Data were obtained from the Military Health System Management Analysis and Reporting Tool (M2). Based on drug fills during fiscal year 2005, patients were stratified as statin users (13,626 patients received at least 90-days supply of statin) or nonusers (32,623 patients never received a statin during the study period). A propensity score-matched cohort of 6972 statin users and 6972 nonusers from this population was created. MEASUREMENTS AND MAIN RESULTS: The occurrence of psychologic disorders between October 1, 2005, and March 1, 2010, was determined using prespecified groups of ICD-9-CM, Psych1: schizophrenia, schizoaffective disorders, and other psychosis; Psych2: major depression and bipolar disorder; Psych3: all psychologic disorders as identified by the Agency for Health Research and Quality-Clinical Classifications (except for categories of childhood or developmental psychiatric disorders). Between matched pairs of statin users and nonusers, the odds ratios and 95% confidence intervals were as follows: Psych1 (0.9, 0.75-1.05), Psych2 (1.02, 0.94-1.11), and Psych3 (1.02, 0.96-1.1), respectively. CONCLUSION: The risk of developing psychologic disorders was similar in this cohort of propensity score-matched statin users and nonusers.
{"Chemical": []}