The cognitive approach views mental disorders like depression as caused by the way people process information and think about events, themselves, and the future. Beck's cognitive model of depression proposes that negative schemas in three areas - about the self, world, and future - can lead to depression. While cognitive behavioral therapy based on this approach has been effective for treating depression, the cognitive model has limitations and cannot fully explain all types and symptoms of depression. It also raises some ethical issues in always attributing negative thinking to faulty cognition rather than realistic appraisal.