State law encourages districts to provide professional development for school personnel on youth mental health.
California Education Code 8804. Award of grants to local educational agency or consortium
The superintendent shall award grants to a local educational agency or consortium to pay the costs of planning and operating, on behalf of one or more qualifying schools within the local educational agency or consortium, programs that provide support services to pupils and their families at or near the school, as follows: (g) For purposes of this chapter, support services shall include case–managed health, mental health, social, and academic support services benefiting children and their families, and may include, but are not limited to: (2) Mental health services, including primary prevention, crisis intervention, assessments, and referrals, and training for teachers in the detection of mental health problems.
California Welfare and Institutions Code 5886. Mental Health Student Services Act
(e) Funding may also be used to provide other prevention, early intervention, and direct services, including, but not limited to, hiring qualified mental health personnel, professional development for school staff on trauma-informed and evidence-based mental health practices, and other strategies that respond to the mental health needs of children and youth, as determined by the commission.
This site higlights a program that provides training to school and district staff on Youth Mental Health First Aid.