Did the introduction of 'dangerousness' and 'risk of harm' criteria in mental health laws increase the incidence of suicide in the United States of America?

INTRODUCTION: Mental health laws limiting involuntary admission to psychiatric hospitals to those assessed to be dangerous or at risk of harm to themselves or others (obligatory dangerousness criteria, ODC) have been introduced in almost every jurisdiction in the United States of America. Some mentally ill patients, who might have been admitted for treatment under previous laws, but who were not admitted because they were not considered 'dangerous', could subsequently have committed suicide. In order to investigate whether or not suicide rates increased after the introduction of ODC, we examined suicide statistics from 48 states and the District of Columbia.
METHODS: We aligned suicide statistics according to the year in which ODC were introduced in each jurisdiction. We then examined suicide rates in the 15 years before and after the introduction of ODC and trends in national and state suicide rates between 1960 and 1990. Meta-analysis was used to examine differences in suicide rates in the year immediately before and in the year immediately after the introduction of ODC.
RESULTS: Between 1968 and 1977, the decade in which ODC were introduced in the majority of jurisdictions, national suicide rates increased from under 11 per 100,000 per annum to over 12.5 per 100,000 per annum. The increase in many jurisdictions occurred in the years immediately before the introduction of ODC. The introduction of ODC was associated with a non-significant increase in suicide rates in the 49 jurisdictions. There was a significant increase in suicide rates after the introduction of ODC in the 19 jurisdictions that introduced ODC prior to 1976.
CONCLUSIONS: The introduction of ODC might have contributed to increased suicide rates prior to 1976. However, a simpler explanation for the finding is that national suicide rates were rising for other reasons in the same period. We did not find an increase in suicide rates in the jurisdictions where ODC mental health laws were introduced after 1976. Hence, the findings of this study do not support the conclusion that ODC laws have a measurable impact on suicide rates.