Forty patients complied with DSM-IV criteria for PTSD at least once in their lives and 26 were suffering it at the time of the survey. Prevalence rates by sex and level of severity were estimated (Table 2). Age at onset was 22.6 (SD = 12.9). Eighty per cent of patients suffering from current PTSD commenced symptoms within 1 week after experiencing the traumatic event. The duration of symptoms in patients who suffered life PTSD was 14.7 years (SD = 13.2).
Factors associated with PTSD
Female sex (OR = 3.2, 95% CI = 1.3 to 7.4), having experienced principal traumatic event at an early age (t = 2.3, P = 0.03), repeatedly experiencing principal traumatic event (Mann–Whitney, P = 0.002) and experiencing multiple different principal traumatic event were all associated with PTSD diagnosis (t = −2.1, P = 0.03).
Acute stress disorder and dissociative symptoms experienced within 48 hours after the event were also associated with PTSD (OR = 4.6, 95% CI 95% = 1.6 to 13.6). There was also a positive correlation between the number of dissociative symptoms and the number of symptoms of PTSD (r = 0.46, P<0.001).
Twenty-five per cent of principal traumatic events were body-contact events (28/111). Of those patients who suffered a body-contact principal traumatic event, 68% (19/28) developed PTSD whereas of those suffering no body-contact principal traumatic event only 25% (21/83) developed it (OR = 6.2, 95% CI = 2.4 to 15.9).
Thirty-six patients were diagnosed as having at least one personality disorder 50% had one diagnosis, 30% had two diagnoses and 20% had more than two). PTSD was significantly associated with personality disorder (OR = 8.3 CI 95% = 3.3 to 20.5) but only at the expense of female sex (female OR = 19.1, CI 95% = 5.1 to 71.1; male OR = 1.1, 95% CI = 0.2 to 6.6). PTSD was also associated with higher personality disorder comorbidity (t = −4.2, P<0.001).
To verify the existence of a different group of patients who had experienced repeated body-contact principal traumatic event at an early age as suggested by the concept of Complex PTSD,15 a cluster analysis based on age at experiencing principal traumatic event (0–16 versus >16 years), type of principal traumatic event (body-contact versus no body-contact) and frequency (1–5 versus >5) was explored by means of cluster analysis. The results are shown on Table 3. As expected there was one group of 18 patients (77% of all PTSD, 17% of those who experienced any type of principal traumatic event) who suffered high frequency body-contact principal traumatic event at an early age (Group A in Table 3). This group was composed mainly of females who experienced from more severe life and current PTSD than group B (life-PTSD mean number of symptoms for group A = 10.9 and for Group B = 6.5, f = 3.5, P = 0.001; current-PTSD for Group A = 7.5 and for Group B = 3.2, f = 4.2, P<0.001). Group A also presented a different symptom profile from Group B in that inability to recall, diminished interest, feeling of detachment and hopelessness were significantly more frequent.
Table 3 Cluster analysis (UPGMA) based on type of principal traumatic event (body-contact vs non body-contact), frequency of principal traumatic event (1–5 vs 5+) and age at experiencing it.
The personality disorders significantly more prevalent on group A were: paranoid, ‘not otherwise specified’ (NOS), dependent and avoidant, in decreasing order of frequency. Significant differences were also found in the mean number of traits of avoidant personality disorder (A = 2.6, B = 0.9; t = 4.1, P<0.001), dependent personality disorder (A = 2.5, B = 1.1; t = 3.0, P<0.001), paranoid personality disorder (A = 2.5, B = 0.6; t = 3.3, P = 0.004), borderline personality disorder (A = 1.8, B = 0.5; t = 3.1, P = 0.005) and any personality disorder (A = 17.9, B = 7.9; t = 4.2, P<0.001).
Multivariate analysis of factors associated with PTSD
Factors found to be significantly related to PTSD in bivariate analysis (age, sex, frequency, multiplicity, body-contact principal traumatic event, dissociative symptoms and personality disorder) were introduced as explanatory variables in a multivariate logistic model. Personality disorder (OR = 7.7, 95% CI = 2.7 to 22.0, P<0.001), frequency of principal traumatic event (OR = 2.0, 95 % CI = 1.3 to 3.2, P = 0.002) and dissociative symptoms (OR = 1.4, 95% CI = 1.1 to 1.7) explained the probability of suffering PTSD (Hosmer and Lomeshow χ2 = 2.1, P = 0.9, Nagerlkerke r2 = 0.47).
Multivariate analysis of factors associated with duration of symptoms
A Cox model was employed to account for the duration of symptoms. Only the presence of personality disorder explained the duration of symptoms (OR = 3.91, 95% CI = 1.38 to 11.9, P = 0.01, model χ2 = 7.59, P = 0.006). Adding severity of symptoms to the model, only severity was associated with duration (OR = 0.7, 95% CI = 0.57 to 0.85, P<0.001, model χ2 = 13.78, P<0.001).