Objective This systematic review determined whether there are specific types of Personality disorders (PD) cluster(s) and/or specific PD disorder(s) that is more likely to occur in people with Non-epileptic attack disorders (NEAD) without epileptic seizures (ES) comorbidity, compared to those with NEAD and comorbid ES, or compared to people with ES only? An ancillary question is: is any such association characteristically affected by comorbidity of the sister axis-1 mental disorders?

Method A systematic search of 4 major databases and reference lists identified 15 studies comprising of a mix of prospective –, controlled-cross-sectional –, non-controlled cross-sectional –, retrospective(of which 2 were controlled studies)–, and 2 case- studies. The main eligibility criteria were that study participants had diagnoses of NEAD and PD made with video-EEG and DSM (III to IV-TR) – respectively, and the relationship between the 2 aforementioned disorders was primarily or secondarily investigated.

Results The result of this systematic review suggests that people with NEAD-only are more likely to have Cluster-B personality disorders and cluster-C PD (as shown by 9 and 4 studies respectively), compared to people with comorbidity of NEAD and ES (2 studies and 1 study showing predominance of cluster B and C respectively). People with NEAD-only and NEAD with ES are much more likely to have cluster-B PD than people with ES. Borderline PD, followed by histrionic PD are the most frequent cluster-B, PDs in NEAD-only and NEAD plus ES patients. People with ES are much more likely to have cluster-C PD than people with NEAD-only or NEAD with ES. Axis-I disorders did not appear to have any pattern of association or influence in regards the link between NEAD and PD.

Conclusion Though the results suggest some specific association between NEAD and PD which is, in the main, in keeping with findings of previous studies, the quality of the individual studies examined in this review was too poor for any firm conclusions to be drawn.