Clinical indicators of the suicide crisis and response to ketamine.

Background: This analysis sought to identify potential clinical targets for the suicide crisis. Characteristics of a useful clinical target include elevation at the time of suicide crisis and responsiveness to rapid-acting interventions. Suicidal ideation (SI), depression, and hopelessness were hypothesized to meet these criteria.

Methods: Participants were 118 adults across the continuum of suicide risk, including 14 high-risk (HR) individuals who had attempted or seriously considered suicide within the last two weeks. Clinical characteristics were evaluated by: 1) comparing individuals with a recent crisis state to those whose suicide crises had resolved; 2) quantifying responses to a semi-structured interview about the time just before a suicide crisis; and 3) comparing symptomatology before and after an open-label ketamine infusion (0.5 mg/kg) in a subset of the HR group (n = 10).

Results: As hypothesized, SI, depression, and hopelessness were elevated just after a suicide crisis and responded to ketamine, although findings were mixed depending on the assessment used. Psychological pain and traumatic stress symptoms were also associated with the suicide crisis and responded to ketamine. Participants reported high levels of SI, depression, and anxiety just before their suicide attempt.

Limitations: Limitations include the small sample size, inconsistent assessments across analyses, and that ketamine was the only intervention examined.

Conclusions: These results underscore the importance of SI, depression, hopelessness, psychological pain, and traumatic stress in this population, all of which were elevated during the suicide crisis and responded to ketamine. A multifactorial and longitudinal approach is indicated to assess and treat suicide risk.