Metacognitive mastery moderates the relationship of alexithymia with cluster C personality disorder traits in adults with substance use disorders.

Cluster C personality disorder traits have been observed in substance use disorders and linked with poorer outcome. One potential factor which may cause these disturbances in personality function is alexithymia, or the inability to name and express emotion. There may be other proximate factors which moderate the impact of alexithymia on the expression of cluster C traits, such as metacognitive mastery, which is the ability to use knowledge about mental states of self and others to cope with distress and solve social problems. To examine the possibility that mastery mediated the effects of alexithymia on cluster C traits, we assessed each of these constructs using the Metacognitive Assessment Scale Abbreviated, Toronto Alexithymia Scale and SCID II among 58 adults in an early phase of recovery from substance misuse disorders in a residential setting. Results of a multiple regression revealed that, after controlling for symptom severity and severity of substance misuse history, metacognitive mastery moderated the effect of alexithymia on number of cluster C traits. A median split and subsequent ANCOVA revealed that participants with higher levels of alexithymia and poorer metacognitive mastery had more cluster C traits than the other groups. These findings may have clinical implications, suggesting that patients with substance use disorders may benefit from treatment which addresses metacognitive mastery.