Suicidal attempts in mood disorder patients : risk indicators, prediction, and reattempts

Abstract

Mood disorders are categorized into major depressive disorder (MDD), and bipolar disorder (BD) which appear to be the most important risk factor for suicide in any psychiatric disorder. When compare to general population, relative risks of suicide are 21.7 times for BD and 20.4 times for MDD. In Thailand, the northern is recognized as the highest rate of completed suicide in the nation; 13.1 compared to 5.9 per 100,000 populations countrywide in 2010. Suicide attempts rate in this area is also remarkably high around 35 per 100,000 populations per year. Mood disorders are in the top five of high burden of disease in psychiatric hospitals in Thailand. Previous suicide attempt(s) are a precondition for complete suicide in mood disorder patients. To prevent future suicide, understanding of the characteristics related to suicide attempts is important and may be beneficial to identify individuals at high risk. However, only a few studies have been conducted in Thailand regarding suicidal behaviors in mood disorder patients. Psychiatrists may not be able to predict who will exactly commit suicide, but they can reduce or eliminate risk. Studies in this thesis were conducted to explore risk indicators, prediction, and suicide reattempts in mood disorder patients seeking care at Suanprung Psychiatric Hospital, Chiang Mai. Risk indicators of suicide attempts in MDD were stressful life event(s), alcohol use, intermittent or poor psychiatric medications adherence, up to two previous suicide attempts, more than two previous suicide attempts, and prescribed antipsychotics. Risk factors that were inversely related to suicide attempts were increasing years of MDD treatment, and antidepressant prescribed. The findings can facilitate clinicians to identify those at risk and set priority by providing appropriate prevention measures. Prospective research testing the validity of the factors proposed should be undertaken in the future. To date, suicide risk screening tools are used to predict a chance for suicide behaviors. They are, however, general tools such as 8Q or HoNOS. To identify high risk patients for suicide attempts such as BD patients, a specific tool should be developed for primary screening. A study in this thesis proposed a risk scoring scheme for suicide attempts in BD patients using clinical prediction rule. A final set of model contains six indicators easily assessed in routine basis including depression, psychotic symptom(s), and number of previous suicide attempts, stressful life event, medication adherence, and years of BD treatment. A total score explained an 88.6% probability of suicide attempts. When categorized BD patients into low risk, moderate risk, and high risk group, it may facilitate and inform clinicians to make clinical decisions for future suicidal acts prevention. Prospective external validation of this risk‐scoring scheme should be further study. In addition, predictive value of the scheme added with a current suicide‐screening tool such as HoNOS score, and personality traits such as impulsivity, aggression, should also be investigated. Frequency of suicide assessments to be performed and impact of systematic assessment in improving care, reduce costs, and accurately defines the targeted objective also recommended for future testing. Reattempt suicide is more common than the first attempt and prevalent in mood disorder patients especially within one year after the index suicide attempt. The incidence of suicide reattempts and suicide completions in Thai cohort were 15.3% and 3.0%, respectively. The risk of suicide attempt or completion following a psychiatric admission is highest immediately following discharge from hospital. Median time to reattempted suicide was 109.5 days for non‐ fatal, and 90 days for completed suicide. Almost 40% reattempted non‐fatal suicide within 90 days. This is an observation of clinical importance. It indicates that follow‐up and treatment during the first year after a suicide attempt need to be put in special attention to prevent suicide repetition. In the same study, three prognostic factors explained 73.3% of the probability of suicide reattempts were over two previous suicide attempts, concomitantly prescribed typical and atypical antipsychotics or antidepressant. Prognostic factors for long‐term suicide reattempts should be further investigated, because they may somewhat differ from the short‐ term follow‐up. Predictive validity of risk factors for future suicide behaviors is in need both in short and long term follow‐up. Additionally, more research should be carried out in those “first‐evers”, who may have different sociodemographic and clinical characteristics compare to “suicide repeaters”. Studies such as reattempt suicide require a larger sample size to examine a broad range of factors including their interactions. Integration of personality traits such as impulsivity, and aggression, are also recommended due to their ability of leading to early recognition of patients at risk.