Abstract
Background
Meehl portrayed pervasive, chronic suicidality as a key sign of schizotypy. Consistent with this view, positive schizotypy predicts concurrent and future suicidality, is particularly predictive of greater lethality, and is a more potent predictor of suicidality than other psychopathology. Whereas the most prominent explanation for this relationship is that it is spurious, several possible causal connections have not been tested. Also, most existing evidence relates to positive schizotypy and psychosis experience. We describe three studies of the schizotypy – suicidality link.
Methods
In the first, we tested whether, as Meehl argued, schizotypy is associated with suicide dread. A general population sample (n = 350) of young adults (18 to 24 years) reported on schizotypy and suicidality, including efforts to avert suicide attempts. In univariate analyses, positive, negative, and disorganized components of schizotypy each significantly predicted persistent or frequent suicidal ideation in the past month (ORs from 2.10 to 3.71), history of attempts with intent to die (1.59 to 2.15), fear or dread of the possibility of making an attempt (1.58 to 1.63), and worry about acting on an unwanted impulse to attempt suicide (2.48 to 2.62). In fully-adjusted analyses (controlling for depression, anxiety, stress, and all schizotypy components), positive schizotypy predicted reporting of greater worry about impulsive suicidal behaviour (OR = 1.71, p = .009, 95% CI 1.15 to 2.56).
In the second, we tested whether the schizotypy – suicidality link can be understood using contemporary suicide theory. In a random sample of high school pupils (n = 177), schizotypy components predicted classification as an active suicidal ideator (R2 = 0.76, 95% CI 0.56 to 0.95). These effects were accounted by the influences of magical thinking, unusual perceptual experiences, and suspiciousness being mediated in part by perceived burdensomeness, as per the interpersonal theory of suicide. However, direct effects were also observed from social anxiety and magical ideation components of schizotypy.
In the third, we modelled latent growth mixtures of suicidality using data from five waves of the Dunedin Multidisciplinary Health and Development Study. We test how growth in suicidality (from 18 to 38 years) is related to psychosis experience (age 11 years) and schizotypy (age 13 and 15 years). Schizotypy predicted membership of a growth class characterised by chronically death- and suicidal-ideation that, in turn, predicted attempt behaviour.
Results
See above.
Discussion
The complexity of the observed links of schizotypy and psychosis experience with suicidality do not lend themselves to being discounted as spurious or due to common underlying causal factors. Research addressing possible causal connections is warranted, as are efforts to identify whether reduction of suicidality may result from interventions targeting features of subclinical psychosis.
Mediating role of borderline personality disorder traits in the effects of childhood maltreatment on suicidal behaviour among mood disorder patients
