The nature of the relationship between optimism and SI is largely determined by how the two variables are measured. If there is a lack of specificity in the measurement, this will affect the findings and their accurate interpretation. Further, as already discussed, the impact of other variables on the relationship is significant; this may not be captured, as variables such as depression and hopelessness are fluid and dynamic, and can reciprocally influence other factors.
1.4.3.1. The Meaning and Measurement of Optimism
Optimism is a broad construct. It may manifest as current explanatory style, or future expectations; may be a personality trait or learned; and may differ from situation to situation (Hirsch & Conner, 2006). Reflecting this breadth, different measures have been employed in studies. Several measures were used to target the future expectations aspect of optimism, including the Life Orientation Test, the Future Disposition Inventory, the Reasons for Living Inventory, and the Arabic Scale of Optimism and Pessimism. To target the explanatory style aspect, the Expanded Attributional Style Questionnaire was used. As well as the breadth and complexity of optimism, it may overlap with related constructs, for example, hope, hopelessness, pessimism, resilience, and purpose or
meaning in life. Depending on the aims and design of the study, it is difficult to determine what the optimism measure is, and is not, tapping into.
Of particular note, O’Connor et al. (2008) used the Future Thinking Task (FTT) in their study. The FTT involves generating potential positive and negative future events; in a specific time period but then generalising out to a broader view of the future. This study was considered eligible for this review as it was deemed that the measurement of a generalised, broader view of a positive future met the definition of optimism (a general expectation of a favourable future; Scheier & Carver, 1985). However, it may also be argued that the FTT measures hope, in its generation of examples of specific positive events in a particular time period. If this is the case, then results may need to be interpreted with caution.
Although, as per the inclusion criteria, each measure was psychometrically reliable and valid, the range of measures used may limit comparison across studies, as they may be tapping into different aspects of this broad optimism construct. This is a limitation of the literature. Understanding optimism may be facilitated by using a standardised approach to measurement. This will more easily allow for findings to be considered as a whole body of literature, the results of which could be subjected to meta-analytic techniques, rather than component parts that cannot easily (or perhaps even usefully) be combined. Further, it may be more helpful to focus on clinical utility. Attributional style may be amenable to change through intervention, whereas personality traits, by definition, are more stable and persistent. Therefore, research may more
usefully focus on optimistic attributional style and its relationship with SI or associated risk factors, rather than dispositional optimism.
1.4.3.2. The Meaning and Measurement of Suicidal Ideations
It may be that levels of optimism are associated with particular aspects of suicidal ideations. For some, SI can broadly be thought of as comprising ideations about a desire or motivation to die by suicide, as well as ideations about the planning and preparation to die by suicide (e.g. Beck & Steer, 1991). Individuals can experience one or both of these aspects of SI. The different aspects are also reflected in the measurement of SI in some instruments. For example, the Beck Scale for Suicidal Ideations (BSSI) and the General Health Questionnaire-Suicidality Subscale (GHQ-SS) can be considered as incorporating ‘motivation’ and ‘preparation’ subscales.
Two studies considered these aspects separately, and both found optimism to be related to only the ‘motivation’ aspect of SI, and not the ‘preparation’ aspect (Amer & Hamdan-Mansour, 2014; Chin & Holden, 2013). ‘Preparation’ ideations are considered to be more active and severe in nature. Chin and Holden (2013) suggest that optimism alone may not be sufficient to buffer the impact of more severe SI (such as those linked with preparation); but that as SI increases in severity, optimism may better work in conjunction with other protective factors, such as social support or self-esteem.
Although these studies consider motivation and preparation ideations separately, other reviewed studies consider SI as a whole. This is worthy of
note, as it may affect comparison among studies in this review. For instance, it is possible that moderate-high SI scores are largely linked with high ‘motivation’ ideations, but not necessarily comparably high ‘preparation’ ideations. It may also be possible that optimism is more strongly associated with ideations linked with a desire to die, rather than ideations about the more active stage of planning.
The difference between ideations and planning is complex. While all suicide plans involve ideations, not all ideations involve planning. Evidence suggests that individuals with different experiences along the suicidality ‘continuum’ may present with different characteristics and risk status (Rudd, Joiner & Rajab, 1996). Therefore, distinguishing between suicide ‘planners’ and ‘ideators’ may be important. However, no reviewed studies do this, instead seeming to present all those reporting ideation as one homogenous group.
As most studies considered SI measured on one continuous scale, it is not possible in this review to tease apart whether optimism is more strongly linked with one aspect of ideations than another. Again, this lack of standardised approach makes comparison across studies difficult, and limits the conclusions it is possible to draw from the literature.