Baca-García E, Diaz-Sastre C, Basurte E, Prieto R, Ceverino A, Saiz-Ruiz J, de Leon J
Department of Psychiatry, Hospital Ramon y Cajal and University of Alcala, Madrid, Spain.
J Clin Psychiatry. 2001 Jul;62(7):560-4. doi: 10.4088/jcp.v62n07a11.
Biological studies suggest that lower serotonergic activity is associated with both greater suicide lethality and impulsive personality traits. These results may lead to the conclusion that impulsivity in the attempt should be associated with greater lethality. However, Klerman's review of epidemiologic suicide studies suggests an inverse relationship between impulsivity and lethality. This seemingly paradoxical relationship between impulsivity and lethality has not been explored in large representative clinical samples of suicide attempts.
During 1996 to 1998, 478 individuals who attempted suicide were studied in a general hospital in Madrid, Spain. Impulsivity was measured as described in the literature by combining 2 items of Beck's Suicidal Intent Scale (active preparation for attempt and degree of premeditation). Lethality of the attempt was assigned 1 of 4 levels according to the need for medical and/or psychiatric treatment.
More than half of the attempts were impulsive (55%; 95% confidence interval [CI], 51% to 59%), approximately one fourth of the attempts had an intermediate level of impulsivity (28%; 95% CI, 24% to 32%), and approximately one sixth of the attempts were not impulsive (17%, 95% CI, 13% to 21%). There was an inverse association between the impulsivity and lethality of the suicide attempt (chi2 = 62.639, df = 6, p < .0001). The most impulsive attempts tended to result in less morbidity, while the less impulsive attempts tended to be more lethal.
If the inverse relationship between impulsivity and lethality is replicated in other large and representative samples, new studies will be needed to clarify the complex interactions between the clinical dimensions (lethality, impulsivity as a state, and impulsivity as a personality trait) and the biological correlates (particularly serotonergic function) of suicidal behavior.
生物学研究表明，较低的血清素能活性与更高的自杀致死率和冲动型人格特质相关。这些结果可能会得出这样的结论：自杀未遂中的冲动性应与更高的致死率相关。然而，克莱曼对自杀流行病学研究的综述表明，冲动性与致死率之间呈负相关。这种冲动性与致死率之间看似矛盾的关系尚未在大型代表性自杀未遂临床样本中得到探讨。
1996年至1998年期间，在西班牙马德里的一家综合医院对478名自杀未遂者进行了研究。冲动性按照文献中的描述进行测量，即结合贝克自杀意图量表的两项内容（自杀未遂的积极准备和预谋程度）。根据医疗和/或精神科治疗的需求，将自杀未遂的致死率分为4个等级之一。
超过一半的自杀未遂是冲动性的（55%；95%置信区间[CI]，51%至59%），约四分之一的自杀未遂具有中等程度的冲动性（28%；95%CI，24%至32%），约六分之一的自杀未遂不是冲动性的（17%，95%CI，13%至21%）。自杀未遂的冲动性与致死率之间存在负相关（χ2 = 62.639，自由度 = 6，p <.0001）。最冲动的自杀未遂往往导致较低的发病率，而较不冲动的自杀未遂往往更具致死性。
如果冲动性与致死率之间的负相关在其他大型代表性样本中得到重复，将需要新的研究来阐明自杀行为的临床维度（致死率、作为一种状态的冲动性和作为一种人格特质的冲动性）与生物学相关因素（特别是血清素能功能）之间的复杂相互作用。
