title: Levels of evidence, causality, and clinical significance.
authors.forename: W Vaughn
authors.initials: WV
authors.lastname: McCall
mesh_terms: D015984:Causality; D003072:Cognition Disorders / Q000209:etiology*; D003863:Depression / Q000628:therapy; D004565:Electroconvulsive Therapy / Q000009:adverse effects*; D006801:Humans; D008569:Memory Disorders / Q000209:etiology; D016032:Randomized Controlled Trials as Topic; D012107:Research Design; D012307:Risk Factors