Method of Attempted Suicide Predicts Completed Suicide

Nancy A. Melville

August 11, 2015

The risk for a completed suicide following an earlier attempt is increased among people with bipolar and depressive disorders, as well as in cases in which the earlier attempt involved as a method hanging or self-harm, according to a large Swedish study.

The study also supported consistent research showing a significantly increased risk for suicide in the first years following an initial attempt.

"Even today, during the 2000's, people who have attempted suicide continue to complete suicide often within a few years, and this applies particularly to certain groups, as to persons with bipolar disorder, psychosis, and severe depressive disorder," said lead author Bo Runeson, MD, PhD, chief physician in psychiatry and professor in the Department of Clinical Neuroscience at Karolinska Institutet, in Stockholm, Sweden.

"We also have shown that the method used at the previous attempt has relevance to the prognosis," he told Medscape Medical News.

The study was published online August 4 in the Journal of Clinical Psychiatry.

Reflection of High Intent

The study involved data from Swedish national registers on 34,219 patients (59% female) who were admitted to hospitals between 2000 and 2005 for suicide attempts.

In following patients for a period of 3 to 9 years, the authors found that 1182 of the patients went on to commit suicide, with the majority (75%) using self-poisoning, such as by drug overdose, as the method.

Patient conditions that showed the strongest risk for completed suicide after a previous attempt included coexisting bipolar disorder (in males, adjusted hazard ratio [HR] = 6.3; 95% confidence interval [CI], 3.8 - 10.3; in females, adjusted HR = 5.8; 95% CI, 3.4 - 9.7) and nonorganic psychotic disorder (in males, adjusted HR = 5.1; 95% CI, 3.5 - 7.4; in females, adjusted HR = 4.6; 95% CI, 2.8 - 7.7).

"By and large, the high suicide risks in bipolar disorder, moderate to severe depression, and nonorganic psychotic disorder were similar and had overlapping confidence intervals," the authors write. "These similar risk levels are in line with previous research."

In addition, the use of the method of hanging in the index suicide attempt strongly predicted a later suicide in males (adjusted HR = 5.3; 95% CI, 4.0 - 7.0) as well as females (adjusted HR = 4.5; 95% CI, 2.5 - 8.1).

The study showed that previous cutting (or slashing of wrists or piercing) was associated with a slightly higher risk for subsequent completed suicide compared with self-poisoning. This was contradictory to findings in a previous Swedish long-term study, also conducted by Dr Runeson and colleagues, which did not show a higher risk with cutting.

Among patients with the combination of the higher risk factors of bipolar disorder and a previous suicide attempt involving self-injury, 20% committed suicide during the follow-up period.

For those with nonorganic psychosis and previous self-injury attempt, the completed subsequent suicide rate was 15.6%; for those with moderate to severe depression and previous self-injury as the method, the rate was 13.9%.

Although studies going back decades have shown an increased risk for suicide after a first attempt, Dr Runeson said that with significant advances in diagnostic and treatment strategies in psychiatry over the years, the expectation was that trends would have at least notably shifted toward improved prognoses among those with a coexisting mental disorder.

"It was a surprise because, while suicide rates have gone down in the large general population, the risk is still very high in the severely ill," he said.

People with serious disorders, such as bipolar disorder, "now often receive highly specialized treatment in units for affective disorders and in outreach teams for psychotic patients."

"Many attempts to improve treatment of suicide attempters have been performed by elaborating clinical guidelines and staff training."

Dr Runeson added that hanging and attempts at self-harm likely increase the risk for subsequent suicide owing to a greater likelihood of success, suggesting greater determination.

"Attempts by hanging, suffocation may reflect high intent," he said. "This applies also to previous attempts by drowning, jumping from heights, and using firearms."

Valuable Research

Although the greater risk for subsequent suicide after an initial attempt is well established, the new study is valuable in expanding knowledge of patient risk, said Juan A. Gallego, MD, an assistant professor of psychiatry at Hofstra North Shore–LIJ School of Medicine and psychiatrist with the Zucker Hillside Hospital, in Glen Oaks, New York.

"This study is very valuable since it had the opportunity to look at a very large representative sample in Sweden," Dr Gallego told Medscape Medical News.

"Additionally, they were able to investigate rates of complete suicide after months or years of an index suicide attempt, which is only possible by having very good national registries."

"Even though the results did not provide any novel, surprising predictors of suicide attempts, it helps to better understand the relationship between previous self-injury and certain psychiatric diagnoses. It also provided more specific information in regards to specific suicide methods by gender."

In another study published online May 29 in Psychiatry Research, Dr Gallego and colleagues looked more closely at suicide risk in 3322 patients with affective and schizophrenia disorders.

The investigators found a higher risk for a suicide attempt among those with affective disorder compared with schizophrenia disorders. Previous suicide attempts and financial or relationship losses were also significantly associated with a current suicide attempt.

Although noting that the findings regarding mood disorders in the new study are consistent with his research, Dr Gallego said more data on age would be useful.

"The authors included age as a covariate in the regression analysis but did not mention if age was a significant predictor of completed suicide," he noted. "I would have liked to know more about the impact of age in this study."

Dr Runeson received direct support from Stockholm County Council, the Karolinska Institute, the Söderström-Königska Foundation, and the Gadelius Foundation. Dr Gallego reports no relevant financial relatinships.

J Clin Psychiatry. Published online August 4, 2015. Full text


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