将以下内容翻译成英文：不过由于重型精神疾病易反复、难治疗、补助范围较小、患病人群量大等原因仍有许多重性精神疾病患者难以支付诊疗费用。2015年国务院颁布了《全国精神卫生工作规划2015-2020年》提出加强对重性精神疾病患者的管理力度继续提高重性精神疾病患者医疗保障水平减轻重性精神疾病患者家庭经济负担。2016年发布城乡统筹更是力图在降低医疗负担的基础上提高农村患者的医疗服务水平和保障水平以缩小城

"However, due to reasons such as the recurrent and difficult-to-treat nature of severe mental illnesses, limited coverage of subsidies, and a large population of affected individuals, many patients with severe mental illnesses still struggle to afford medical expenses. In 2015, the State Council issued the 'National Mental Health Work Plan (2015-2020)', which proposed strengthening the management of patients with severe mental illnesses, continuing to improve the level of medical security for these patients, and reducing the financial burden on their families. The release of the Urban and Rural Integration Plan in 2016 aimed to improve the level of medical services and security for rural patients on the basis of reducing medical burdens, in order to narrow the gap in medical service levels between urban and rural residents and establish medical fairness."