Analgesia during self-cutting: Clinical implications and the association with suicidal ideation
*Toshihiko Matsumoto, MD, PhD, Center for Suicide Prevention, National Institute of Mental Health, National Center of Neurology and Psychiatry, 4-1-1 Ogawa-Higashi, Kodaira, Tokyo 187-8553, Japan. Email: email@example.com
The present study examined the association of suicidal ideation in self-cutters with clinical features of self-cutting, using a sample of subjects from juvenile correctional institutions. Multivariate analysis revealed that male self-cutters and analgesia during self-cutting were significantly associated with a history of suicidal ideation. These results suggest that male analgesic self-cutters should be regarded as a high-risk subgroup for suicide.
NON-FATAL SELF-CUTTING IS an internationally common mental health problem in adolescents and young adults.1 Self-cutting such as cutting one's own wrist and arm often appears to be performed histrionically without suicidal intent, although a systematic review found that non-fatal self-injury is an important risk factor associated with future complete suicide;2 therefore, careful evaluation of self-cutting is required.
However, it is unclear as to what aspects of the clinical features of self-cutting can be used to predict future suicidality. One cohort study found that repetition of self-cutting indicates future suicidality,3 while a renowned clinician suggested that dissociation and analgesia (lack of pain perception) during self-cutting reflects a severe psychopathology.4 Our previous study reported that a history of suicide attempts is closely associated with the coexistence of other methods of self-injury such as burning oneself with a lit cigarette, as well as self-cutting.5 Because the epidemiological study did not collect data on clinical variables such as pain perception during self-cutting,3 it has not yet to be demonstrated whether repetition of self-cutting, analgesia during self-cutting, or coexistence of other methods of self-injury is more closely associated with suicidality in self-cutters.
The purpose of the present study was to clarify the association of suicidal ideation in self-cutting individuals with repetition of self-cutting, pain perception during self-cutting, and coexistence of other methods of self-injury such as hitting or burning oneself. We used a sample of patients at correctional institutions where a higher prevalence of self-cutting has been reported than in the general population.5
SUBJECTS AND METHODS
The subjects were 636 adolescents and young adults (aged 13–21 years; mean age ± SD, 17.0 ± 1.9; 572 males and 64 females) who consented to participate in this study from a pool of 641 adolescents and young adults (99.2%) continuously incarcerated between September 2006 and March 2007 at the Yokohama Juvenile Detention Center and the Kurihama Reformatory, Japan. We explained to all subjects that the results of this study would not influence their treatment because the information obtained from each participant would be not be disclosed to institute staff. Written informed consent was obtained from all participants, and the Ethics Committee of the National Center of Neurology and Psychiatry gave its approval for the present study.
We administered a self-reporting questionnaire designed to evaluate an individual's self-injurious behavior and suicidal ideation. This questionnaire included six items concerning repetition of self-cutting, pain perception during self-cutting, and coexistence of other methods of self-injury. The first question (self-cutting) asked ‘Have you ever cut yourself deliberately?’ If the participants reported a history of self-cutting, the following questions were asked: ‘Have you cut yourself on more than 10 occasions?’ (repetition), ‘Did you usually perceive no pain when engaging in self-cutting?’ (analgesia), ‘Have you ever hit yourself, or made yourself hit a hard object such as a concrete wall on purpose?’ (coexistence of self-hitting), ‘Have you ever deliberately burned yourself with a lit cigarette?’ (coexistence of self-burning), and ‘Have you ever wanted to die, or kill yourself?’ (suicidal ideation). All questions were answered with ‘Yes’ or ‘No’.
This self-reporting questionnaire was distributed to all participants within their first week of entry into the study, and the anonymously completed materials were collected a few days later. We selected subjects with a history of self-cutting based on the answers provided to the first question. Then, to determine the factors associated with a history of suicidal ideation in the self-cutting subjects, logistic regression analysis was employed for the five variables (gender differences, repeated self-cutting, analgesia, and coexistences of self-hitting and self-burning), and unadjusted and adjusted Odds ratio were calculated. P-values under 5% were accepted as indicating significance, and all P-values were two-tailed. All statistical analyses were performed using SPSS software for Windows (version 12.0: SPSS, Chicago, IL, USA).
In the present study, 142 subjects (22.3%; 106 males and 36 females) reported a history of self-cutting. Of the 142 self-cutting subjects, 91 (64.1%) reported a history of suicidal ideation, 48 (33.8%) reported repeated self-cutting, 50 (35.2%) reported analgesia during self-cutting, and 114 (80.3%) and 84 (59.2%) reported a coexistence of self-hitting and self-burning, respectively.
Table 1 shows the results of the logistic regression analysis undertaken to clarify the factors associated with a history of suicidal ideation in the self-cutting subjects. The monovariate analysis demonstrated that of the five variables, gender differences (unadjusted Odds ratio, 2.828; P = 0.025), analgesia (unadjusted Odds ratio, 4.316; P = 0.001), and coexistence of self-hitting (unadjusted Odds ratio, 2.633: P = 0.029) were significantly associated with a history of suicidal ideation in the self-cutting subjects. These results indicated that the self-cutting subjects with a history of suicidal ideation showed higher female percentage, and more frequently reported analgesia during self-cutting and a history of self-hitting.
Table 1. Logistic regression analyses on history of suicidal ideation in self-cutting subjects
|Gender differences (male = 0, female = 1)||1.039||2.828 (1.136–7.038)*||−1.446||0.236 (0.073–0.760)*|
|Repeated self-cutting||0.674||1.962 (0.896–4.294)||0.197||1.218 (0.509–2.916)|
|Analgesia||1.462||4.316 (1.804–10.324)*||1.225||3.405 (1.314–8.823)*|
|Coexistence of self-hitting||0.968||2.633 (1.106–6.271)*||0.719||2.053 (0.685–6.151)|
|Coexistence of self-burning||0.129||1.138 (0.563–2.300)||0.499||1.647 (0.706–3.843)|
However, the multivariate analysis demonstrated the different results from the monovariate analysis; gender differences (male = 0, female = 1; adjusted Odds ratio, 0.236; P = 0.016) and analgesia (adjusted Odds ratio, 3.405; P = 0.012) were significantly associated with a history of suicidal ideation. These results indicate that male self-cutters who usually experience analgesia when engaging in self-cutting are more likely to have a history of suicidal ideation.
To our knowledge, this is the first study to have examined the association of the clinical features of self-cutting, including analgesia, with suicidal ideation. Although a previous study found that repeated self-cutting and other methods of self-injury indicate future suicidality,3 the study did not consider pain perception during self-cutting.
The present study found that a history of suicidal ideation may be associated with males and analgesia during self-cutting. The association between males and suicidality found in our study appear to be consistent with a previous study which reported that males are more likely than females to commit suicide.6 However, this gender factor demonstrated by the multivariate analysis was contradicted with that by the monovariate analysis. This contradiction may be caused by deviated gender-ratio of our sample. Accordingly, this association may be limited in self-cutting males while self-cutting females may be a heterogeneous subgroup.
Why then is analgesia closely associated with suicidal ideation? Analgesic self-cutters do not necessarily cut themselves with suicidal intent, but they do experience more suicidal ideation than the non-analgesic self-cutters. Many studies suggest that such analgesia is caused by dissociation/depersonalization, indicating a sequential process of self-cutting influenced by dissociation/depersonalization,4,7,8 although the association between analgesia and dissociation was not confirmed using the Dissociative Experiences Scale9 in the present study. Bohus et al. experimentally demonstrated that self-cutters ordinarily have a high baseline pain threshold, which is further elevated with distress.7 They suggested that self-cutters may cope with distress through dissociation/depersonalization, and that consequently they may avoid suicidal ideation and emotional outbursts. Suyemoto suggested that the intensity of dissociation/depersonalization is at its peak just before self-cutting, which is why some self-cutters feel no pain during cutting and why they then feel a release afterward, with the dissociative/depersonalized symptoms decreasing immediately.8 This leads us to speculate that for some self-cutters, self-cutting may be a strategy to survive, and that they may find it difficult to suppress suicide ideation unless they cut themselves. This is also supported by our previous study10 which found that self-cutters with dissociation more frequently reported ‘I need self-cutting to survive’ than those who did not dissociate.
While analgesia/dissociation may be effective in avoiding psychological distress including suicidal ideation in the short term, we suggest that male analgesic/dissociative self-cutters should be regarded as a high-risk subgroup for suicide in the long term because of history of suicidal ideation. Kessler et al. demonstrated that suicidal ideation in adolescence was closely associated with future suicidal behavior.11 In addition, as Walsh and Rosen warned,12 although self-injurers often lack suicidal intent when they engage in self-injury, they often have suicidal ideation when they do not engage in such behaviors, and some of them attempt suicide with methods different from those ordinarily used in self-injury; therefore, suicidal ideation reported by self-cutters should be recognized as a factor indicating future suicidality, even if they have never cut themselves with suicidal intent.
The present study has four limitations. First, the study was conducted in correctional institutions, meaning that generalization of the results is limited. Second, data were acquired via self-reporting questionnaires rather than by semi-structured interviews or a collection of collateral information; however, Hawton et al. claimed that unsigned self-reporting questionnaires are the best way to investigate self-injury in adolescents.1 Third, the gender ratio of our sample was deviated, although a multivariate analysis was performed to eliminate the influences of confounding factors. Finally, this study employed a cross-sectional design rather than a prospective design. Despite these limitations, this is the first study to indicate an association between analgesia during self-cutting and suicide ideation.