Table 1 Inclusion and exclusion criteria for the Oral Ketamine Trial on Suicidality (OKTOS)

● Persons aged ≥18 years

● Psychiatric conditions:

 ○Psychosis

 ○Mania/hypomania

 ○Acute suicidal ideation requiring urgent psychiatric intervention

● Participants with chronic suicidal thoughts as the primary presenting complaint, determined by Beck Scale for Suicide Ideation – 21 items (BSS) score ≥ 6 at screening

● Physical conditions:

 ○ Uncontrolled/severe symptomatic cardiovascular disease states including recent myocardial infarction (within prior 6 months); history of stroke; and hypertension (resting blood pressure > 150/100)

 ○History of intracranial mass, intracranial haemorrhage/stroke, cerebral trauma/traumatic brain injury or increased intracranial pressure (as assessed by referring general practitioner)

 ○ liver function test results out of normal range, as specified:

  ▪alanine aminotransferase: >  135 U/L

  ▪aspartate aminotransferase: >  123 U/ L

  ▪gamma glutamyl transferase male participants: >  210 U/L

  ▪gamma glutamyl transferase female participants: >  135 U/L

  ▪total bilirubin > 60 umol/L

  ▪albumin: <  25 g/L and > 150 g/L

  ▪alkaline phosphatase: >  345 U/L

● Previous reaction to ketamine (as reported by referring general practitioner and participant)

● Pregnant women

● Breastfeeding women