Why do we need 3 separate classifications?
A single suicidality phenomenon can occur as an isolated phenomenon, as part of a suicidality event, or as part of a suicidality disorder. Consider 2 separate suicidality events. In the first example the patient has the thought “I want to kill myself”. This thought is both a single suicidality phenomenon and a single suicidality event. In the second event the patient has the thought “I want to kill myself”, immediately followed by the thought “I will overdose on medication.” This is a single suicidality event, but the event is made up of 2 separate suicidality phenomena. The first phenomenon in the event is an active suicidal ideation and the second phenomenon in the event is a suicidal method. Both of these examples (1 & 2 above) are examples of events of suicidality. An event of suicidality can include only one phenomenon (as in example 1) or can include several phenomena (as in example 2). (More details are in the suicidality phenomena classification and suicidality events classification [the T-CASA] linked to below.)
We define an episode of suicidality as an event of suicidality followed by at least 24-hours without any suicidality. Consider a third example, the thought “I want to die”, followed by 24 hours without any suicidality. That is a single episode of suicidality. An episode of suicidality may contain only one event of suicidality or it may contain multiple events of suicidality. Consider a fourth example, the thought “I want to die” that occurs one morning at 6 am. At 8:30 am that morning the patient has the thought “I want to kill myself.” These are two distinct events, each with a distinct phenomenon. The patient has no additional suicidality for the next 24-hours. The two thoughts count as one episode because they are followed by 24-hours without suicidality. 3 of our suicidality disorders require only one episode to have a suicidality disorder. However, 7 of our suicidality disorders require 3 or more episodes to have a suicidality disorder. (More details are in the suicidality episode & event classification linked to below.)
The Sheehan & Giddens suicidality phenomena definitions provide a nomenclature to classify the phenomena of suicidality. This nomenclature contains definitions that avoid the Type I and Type II errors inherent in other suicidality nomenclature systems. The following link also contains links to crosswalks between the Sheehan & Giddens suicidality nomenclature and the 4 other nomenclature systems.
The Tampa – Classification Algorithm for Suicidality Assessment (T-CASA) is an algorithm to collect the details of each event of suicidality. The T-CASA provides a coding system for all combinations of suicidality phenomena experienced within each event. The T-CASA permits detailed analyses of specific phenomena. Such analyses could assess whether a treatment worsens specific suicidality phenomena. We designed the T-CASA to avoid the Type I and Type II errors inherent in the other suicidality event classification systems.
Suicidality Episodes & Disorders
Clozapine may control suicidal command hallucinations. Lithium often reduces suicidality in patients with Bipolar Disorder. Antidepressants may reduce suicidality in elderly patients with Major Depressive Disorder. NMDA-receptor antagonists, like ketamine, may reduce suicidality in others. Response to any one treatment is not trans-nosological.
Sheehan & Giddens created a phenotypic classification system for suicidality episodes and suicidality disorders. This phenotypic classification may help clinicians better select a treatment based on the patient’s phenotype. The suicidality disorders classification provides a system to gather phenotypic-specific information on each suicidality disorder. A good phenotypic classification may provide better predictive models of treatment response for those at risk of dying by suicide.
The above classification systems were originally published in Suicidality: A Roadmap for Assessment and Treatment.