Mental ill-health has been termed the pandemic of the 21st century, and a large share of those exposed do not receive treatment. Many people with depression, anxiety and other mental health problems consult complementary or alternative medicine (CAM), and CAM is used in conventional psychiatric care, in Sweden and in other countries. However, the extent to which CAM is used in psychiatric care, and for what purposes, are largely unknown. This study is based on a survey distributed to all heads of regional, municipal, private and governmental health care units treating persons with psychiatric symptoms across Sweden in 2019. CAM was reportedly used by 62% of the 489 responding health care units, for symptoms including anxiety, sleep disturbances and depression. Main motivations for CAM use were symptom relief, meeting patients' requests and reduced demand for pharmaceutical medication. Very few respondents reported side effects. The most common reason for interrupting CAM use at a unit was a lack of trained professionals. This study confirms the need for further research about CAM, and for CAM education and training among healthcare professionals.