Survival analysis of suicide risk after attempted suicide

Survival analysis of suicide risk by sex and age after attempted suicide was studied in a cohort of 1573 suicide attempters referred to the psychiatric emergency room at the Karolinska Hospital from 1981 to 1988. The time course of suicide risk and the overall prognosis after attempted suicide and, in particular, the possible usefulness of sex and age as risk factors for the prediction of suicide risk after attempted suicide was analyzed. Nearly two thirds of the sample were women and most of the suicide attempters were young (in their twenties and thirties), and the median age was 35 years. The overall mortality after a 5-year mean observation period after attempted suicide was 11%, and the suicide mortality was 6 %. The suicide risk after attempted suicide among men (8.3%) was nearly twice the female suicide risk (4.3%). Age as a possible suicide risk factor was analyzed for each sex separately by median split subgrouping. It was concluded that both older and younger male suicide attempters are at high risk of suicide (7% and 10% respectively), and older women are at higher risk than younger (6%, vs 2%). The suicide risk is particularly high during the first year after the suicide attempt. The high suicide risk group of young adult male suicide attempters is one of the main feasible targets of psychiatric intervention research programs on suicidal behavior. Suicide among young men is a major cause of years of life lost.     

Quasi-objective nonlinear principal component analysis

By means of mathematical analysis and numerical experimentation, this study shows that the problems of non-uniqueness of solutions and data over-fitting, that plague the multilayer feedforward neural network for NonLinear Principal Component Analysis (NLPCA), are caused by inappropriate architecture of the neural network. A simplified two-hidden-layer feedforward neural network, which has no encoding layer and no bias term in the mathematical definitions of bottleneck and output neurons, is proposed to conduct NLPCA. This new, compact NLPCA model alleviates the aforementioned problems encountered when using the more complex neural network architecture for NLPCA.The numerical experiments are based on a data set generated from a well-known nonlinear system, the Lorenz chaotic attractor. Given the same number of bottleneck neurons or reduced dimensions, the compact NLPCA model effectively characterizes and represents the Lorenz attractor with significantly fewer parameters than the relevant three-hidden-layer feedforward neural network for NLPCA.     

Functional principal component analysis of fMRI data

We describe a principal component analysis (PCA) method for functional magnetic resonance imaging (fMRI) data based on functional data analysis, an advanced nonparametric approach. The data delivered by the fMRI scans are viewed as continuous functions of time sampled at the interscan interval and subject to observational noise, and are used accordingly to estimate an image in which smooth functions replace the voxels. The techniques of functional data analysis are used to carry out PCA directly on these functions. We show that functional PCA is more effective than is its ordinary counterpart in recovering the signal of interest, even if limited or no prior knowledge of the form of hemodynamic function or the structure of the experimental design is specified. We discuss the rationale and advantages of the proposed approach relative to other exploratory methods, such as clustering or independent component analysis, as well as the differences from methods based on expanded design matrices.     

Attempted suicide predicts suicide risk in mood disorders

Suicide risk was studied in a sample of 346 mood disorder inpatients, 92 of whom were admitted after a current suicide attempt. The overall suicide mortality after a mean observation period of 6 years was 8%. The potential of attempted suicide to predict suicide risk in hospitalized patients with mood disorders was studied by survival analysis after subgrouping on the basis of whether a current suicide attempt had occurred or not. The suicide risk the first year after attempting suicide was 12% (11/92), compared with 2% (4/254) in the mood disorder subgroup with no current suicide attempt. The long-range suicide risk after a current suicide attempt in depression was 15% (14/92) as compared with 5% (13/254) among those without a current suicide attempt. It is concluded that a current suicide attempt in mood disorder inpatients predicts suicide risk particularly within the first year and should be taken very seriously.     

Attempted suicide in hospitalised schizophrenics

A group of 25 hospitalised schizophrenics who had attempted suicide within the past year was compared with another group of 30 hospitalised schizophrenics who had not attempted suicide, using the PSE symptoms. The former had a significantly higher number of symptoms indicative of a depressive disorder. It is concluded that suicidal risk in schizophrenia is significantly raised when there are concomitant depressive symptoms.     

Age-specific characteristics of attempted suicide in adolescence

A total of 422 suicide attempts of adolescents (15 to 19 years of age) were investigated and compared with 327 suicide attempts of young adults. Adolescents had more serious social problems than young adults. Their adaptive problems became worse while growing older until the age of 20. Adolescents made suicide attempts with serious intent more often than young adults, but their suicide attempts were not as often lethal as in young adults. Although repeated suicide attempts were relatively common in both groups, only 10 people were part of both materials. Adolescents were as often psychotic when attempting suicide as young adults were. Twenty-four percent of adolescents and 26% of young adults were admitted to a psychiatric hospital as treatment.     

Risk factors associated with suicide attempt in young French people

Demographic data, personal and familial characteristics, as well as DSM-III-R-based psychiatric diagnoses were collected in 369 adolescents and young adults aged between 15 and 29 years, referred to an Emergency Department for psychological problems. In total, 60% of them were suicide attempters. Separations before the age of 12 years and depression in the family emerged as the main features distinguishing the suicidal group from the psychiatric control group. Fifty per cent of suicide attempters were repeaters. Fostering during childhood, suicide attempts and depression in the family were found to be risk factors for repeated self-attempts. These results support the view that significant levels of dysfunction, together with increased psychiatric morbidity, especially suicidal behaviour, characterize the families of young self-attempters.     

Attempted suicide and suicide in functional psychoses.

A total of 2,243 first admissions to Gaustad Hospital between 1938 and 1961 diagnosed as functional psychotics were either followed up to the time of their death within 5 years, or observed over a period of 5 years, and then reexamined. Of these patients, 325 had attempted suicide prior to their admission. The frequency of attempted suicide was equal in both sexes. Men appeared to use more dangerous methods, and to have more serious intentions. The psychosis appears to have been of importance when considering whether, but not how the suicide should be attempted. The greatest risk of attempted suicide was to be found amongst patients with psychoses of a depressive nature. Twenty-eight of the 2,243 patients in this study committed suicide within 5 years following their discharge, and a further 20 took their own lives prior to the reexamination. A certain connection can be seen between attempted suicide and psychotic symptoms.     

Rates and correlates of suicide attempts in first-admission psychotic patients

The relationship of attempted suicide to demographic characteristics, current and lifetime psychiatric diagnoses, clinical history, and current symptoms was assessed in a sample of 184 recently hospitalized psychotic patients. Forty-three patients (23%) had an attempt history, and 28 (15% of sample; 65% of attempters) made an attempt during the episode for which they were hospitalized. Demographic characteristics did not distinguish attempters from nonattempters. Variables significantly associated with having ever attempted suicide were current diagnosis of unipolar major depressive disorder but not bipolar; lifetime major depressive episode; a history characterized by a less acute onset, lower pre-admission psychosocial functioning, and episodes of physical violence; and a symptom picture characterized by greater depression, hopelessness, negative symptoms, hallucinations and less thought disorder. Those with a current attempt had significantly higher rates of lifetime history of major depression and less physical violence than those with past attempts only. The potential importance of the data for predicting future suicidal acts is discussed.     

Clinical correlates of intent in attempted suicide.

The seriousness of suicide attempts was evaluated in 62 consecutive referrals in 2 general hospitals. As measured by the Suicide Intent Scale (SIS) the majority of cases had a low to moderate intention to die. Increasing age, psychosis and deliberate self-injury were associated with high suicidal intent. Hopelessness and a sense of isolation are significantly more frequent antecedent ideo-affective states in cases with high intent and anger and frustration are more prevalent in cases with low intent. Two other measures of seriousness, the medical condition on admission and lethality of the method used, correlate significantly with the degree of intent. The SIS can distinguish between relatively homogeneous subgroups of suicide attempters for depth studies of aetiology and management.     

Attempted suicide and depression in schizophrenia

The relationships between symptoms and both prior suicide attempts and current suicidal thinking were examined in a sample of schizophrenics at 2 points in time. Fifty subjects meeting DSM-III criteria for schizophrenia were assessed within 1 week of admission, and 41 were reassessed at a 6-month follow-up. On admission, prior suicide attempts were significantly associated with current depression, female sex, lower education and more frequent hospitalization. The association with depression remained significant at follow-up. In addition, current suicidal thinking was associated with depression at both times but also with negative symptoms at time 1 and delusions and hallucinations at time 2. These findings confirm and strengthen prior reports of an association between depression and attempted suicide.     

Constrained principal component analysis reveals functionally connected load‐dependent networks involved in multiple stages of working memory

Constrained principal component analysis (CPCA) with a finite impulse response (FIR) basis set was used to reveal functionally connected networks and their temporal progression over a multistage verbal working memory trial in which memory load was varied. Four components were extracted, and all showed statistically significant sensitivity to the memory load manipulation. Additionally, two of the four components sustained this peak activity, both for approximately 3 s (Components 1 and 4). The functional networks that showed sustained activity were characterized by increased activations in the dorsal anterior cingulate cortex, right dorsolateral prefrontal cortex, and left supramarginal gyrus, and decreased activations in the primary auditory cortex and “default network” regions. The functional networks that did not show sustained activity were instead dominated by increased activation in occipital cortex, dorsal anterior cingulate cortex, sensori‐motor cortical regions, and superior parietal cortex. The response shapes suggest that although all four components appear to be invoked at encoding, the two sustained‐peak components are likely to be additionally involved in the delay period. Our investigation provides a unique view of the contributions made by a network of brain regions over the course of a multiple‐stage working memory trial. Hum Brain Mapp, 2011. © 2010 Wiley‐Liss, Inc.     

Attempted suicide by elderly Chinese in Singapore

Background: There is a paucity of data on attempted suicide by elderly people in Asian countries. The present paper compares suicide attempts of elderly and young Chinese living in Singapore. Methods: The present study was conducted in a general hospital from 1991 to 2000. All patients were interviewed by a psychiatrist and diagnoses were based on the 3rd edn (revised) of the Diagnostic and Statistical Manual (of Mental Health disorders) (DSM III R) or 4th edn of the Diagnostic and Statistical Manual (of Mental Health disorders) (DSM IV) classification. As well as demographic data, reasons for the suicide attempt and methods used were noted. Results: In the 10 years of the study there were 1568 young (64 years and younger) and 61 elderly (65 years and older) Chinese patients. The male to female ratio was the same in each group. Multiple logistic regression analyses showed that the elderly were more likely to have ingested benzodiazepines (OR: 3.19, CI: 1.34–7.57, P = 0.009), to have a diagnosis of depression (OR: 464, CI: 1.94–11.10, P = 0.001) and to suffer from a physical illness than were the young (OR: 4.39, CI: 1.92–10.04, P = 0.000). Conclusion: The majority of Chinese elderly who attempted suicide had depression and were more likely to have been prescribed benzodiazepines than antidepressants. Prevention strategies in the future should include training programs for doctors to enable them to identify depression and treat depression effectively.     

Oriented principal component analysis for large margin classifiers

Large margin classifiers (such as MLPs) are designed to assign training samples with high confidence (or margin) to one of the classes. Recent theoretical results of these systems show why the use of regularisation terms and feature extractor techniques can enhance their generalisation properties. Since the optimal subset of features selected depends on the classification problem, but also on the particular classifier with which they are used, global learning algorithms for large margin classifiers that use feature extractor techniques are desired. A direct approach is to optimise a cost function based on the margin error, which also incorporates regularisation terms for controlling capacity. These terms must penalise a classifier with the largest margin for the problem at hand. Our work shows that the inclusion of a PCA term can be employed for this purpose. Since PCA only achieves an optimal discriminatory projection for some particular distribution of data, the margin of the classifier can then be effectively controlled. We also propose a simple constrained search for the global algorithm in which the feature extractor and the classifier are trained separately. This allows a degree of flexibility for including heuristics that can enhance the search and the performance of the computed solution. Experimental results demonstrate the potential of the proposed method.     

Temperamental vulnerability in attempted suicide

The aim of this study was to explore and describe features of suicidal temperament and to describe the psychological domains of vulnerability in attempted suicide. Thirty-two suicide attempters were compared with 32 sex- and age-matched convalescent surgical controls on self-report personality inventories; the Eysenck Personality Questionnaire, the Chapman Scales, the Beck Hopelessnes Scale and the Karolinska Scales of Personality. Suicide attempters showed higher scale scores on neuroticism, psychoticism, interpersonal aversiveness, perceptual aberration, nonconformity, hopelessness, somatic anxiety, muscular tension, indirect aggression, suspicion and lower socialization. The features of suicidal temperament include hopelessness and anhedonia, anxiety, hostility and undirected anger expression, psychosis proneness, antisocial traits and interpersonal difficulties. These temperamental features might render the suicidal individual particularly vulnerable to suicidal behavior.     

Attempted suicide: repetition and survival--findings of a follow-up study.

OBJECTIVE: This was a prospective follow-up study of suicidal patients to assess the influence over time of different risk factors, whether on completed suicides or reattempts. Survival analysis makes it possible to weigh the influence of variables that increase or decrease a patient's life span or that make reattempts less likely. METHOD: A cohort of 150 patients admitted to a psychiatric department after a suicide attempt was followed up over 10 years. The study protocol used standardized criteria, and periodic controls were carried out in all patients. RESULTS: In total, 12% of patients completed suicide, 10% died from natural causes, 75% were still alive and 25% reattempted. In the survival analysis the risk for completed suicide or reattempting was highest during the first 2 years after the index attempt admission. Global Assessment of Functioning (GAF) was the factor that most increased survival time. The number of previous attempts decreased survival time and increased the risk of reattempts. CONCLUSION: Since suicidal risk varied over time, intensifying contact with patients during periods of psychopathological change or life events could prolong their survival.     

Suicide and attempted suicide reported by general practitioners in Belgium, 1990–1991

In 1990–1991 the Belgian sentinel network of general practitioners recorded suicide and suicide attempts within their practices. The annual attempted suicide rate is estimated at 13.0 cases per 10,000 inhabitants. The highest incidence rates are found among women and young people. The annual suicide rate is estimated at 2.3 cases per 10,000 inhabitants, with the highest rates in men and in elderly people. The highest incidence rates of suicide attempts as well as of suicide are found among divorced people. About 30% of the attempters and committers made at least one earlier attempt. Drug overdose and hanging are the most frequently used methods, respectively when attempting and committing suicide. About 60% of both committers and attempters contacted their general practitioner within a period of 1 month preceding the attempt. Nearly half of the attempters and of the committers were treated for a mental disorder in the year preceding the attempt.     

Suicide and attempted suicide in a general hospital in western Ethiopia

ABSTRACT Suicidal behaviour in western Ethiopia as seen in a general hospital is reported on. The suicide rate is at least 3–11 per 100,000 inhabitants per year (mean 4.5) which is higher than is usually reported from Africa. As many women as men seem to commit suicide and the incidence is highest in the age group 19–24 years and lowest in the oldest group. The incidence seems to be higher in urban areas. Hanging is the most frequent method used by both sexes.     

The Marke-Nyman Temperament (MNT) Scale in suicide attempters

A total of 89 suicide attempters were diagnosed according to the DSM-III-R, and categorized according to suicide method as ‘violent’ and ‘non-violent’ attempters, and also as those who had made previous suicide attempts (‘repeaters’) and those who had not (‘non-repeaters’). All of the subjects completed the MNT questionnaire. Our hypothesis was that the temperament patterns would reflect specific clinical characteristics, such as psychiatric diagnoses and type of suicidal behaviour. The ‘validity’ (ranging from fatiguableness to a high level of psychic energy) showed a bimodal distribution, suggesting the existence of two subgroups. The subjects with adjustment disorders displayed a significantly higher mean validity than the other patients. The lowest validity scores were found in subjects with bipolar depression. Men showed significantly higher 'stability’ (reflecting emotional distance from others) than women. Subjects with major depression and those who were ‘violent’ suicide attempters showed somewhat higher 'solidity’ (unchangeability, non-impulsiveness) compared with the other groups. Female ‘non-repeaters’ displayed significantly lower solidity than males or other females. In general, no clear temperament patterns were detected in patients categorized according to type of suicidal behaviour. In contrast to the findings of studies of normal populations, the intercorrelations between the dimensions were considerable, especially among the men. This prompted us to perform a cluster analysis procedure in which the subjects were allocated to five clusters according to the MNT dimensions. No distinct clinical characteristics appeared in these clusters, except in the cluster with the highest validity and the lowest stability, as 54% (P= 0.014) of the patients in this cluster had an adjustment disorder diagnosis. These temperament results reflect the clinical heterogeneity of patients who attempt suicide.     

Trends in suicide in Sweden 1749-1975.

Changes in the suicide rate in Sweden have been studied over the period 1749-1975. It has risen from about 2 per 100,000 inhabitants at the middle of the 18th century to about 20 per 100,000 during the period 1971-1975. Thus a more than tenfold increase is evident. From the non-standardized figures a real and substantial increase can be demonstrated which becomes even more apparent after standardization. This increase is independent of variations in the age composition of the population. The increase has occurred in the younger age groups: between the ages of 20 and 35 years, i. e.during the most active years of life, suicide is the leading cause of death today. An account of legislative measures for suicide prevention during this period is also presented. There is considerable support for the assumption that the low suicide rate registered in Sweden up to the beginning of the 19th century was an effect of the powerful influence of religion over the population.