Background: Previous research has highlighted the importance of surveillance of suicide methods to identify emerging patterns and to support prevention strategies. We aimed to investigate trends in suicide methods by people who had been in contact with mental health services in the 12 months before death. Method: We examined method-specific trends among psychiatric patients in the UK who died by suicide between 2000 and 2021 using an exploratory joinpoint regression analysis. Data were collected as part of the National Confidential Inquiry into Suicide and Safety in Mental Health. Findings: The overall trend in patient suicide showed a significant decrease over the study period, with a non-significant increase between 2000 and 2011, and a significant decrease between 2011 and 2021. Hanging increased by 1.9% every year throughout the study period whilst drowning steadily decreased by 2.8% every year. Deaths by self-poisoning and gas inhalation both decreased by 1% and 6% every year respectively, although the trend for self-poisoning was not significant. Cutting/stabbing deaths significantly increased by 4.8% annually. No significant trends were identified for deaths by jumping/multiple injuries. Discussion: The increase in patient suicide deaths by hanging is of concern and may be the result of method substitution and policies targeting the prevention of other methods. Attention should be paid to the steady increase in deaths by cutting/stabbing. Our findings support the need for surveillance, including real-time surveillance, of emerging methods and continued efforts towards means restriction.