Xavier F. Amador

Suicide risk in schizophrenia: learning from the past to change the future

Suicide is a major cause of death among patients with schizophrenia. Research indicates that at least 5–13% of schizophrenic patients die by suicide, and it is likely that the higher end of range is the most accurate estimate. There is almost total agreement that the schizophrenic patient who is more likely to commit suicide is young, male, white and never married, with good premorbid function, post-psychotic depression and a history of substance abuse and suicide attempts. Hopelessness, social isolation, hospitalization, deteriorating health after a high level of premorbid functioning, recent loss or rejection, limited external support, and family stress or instability are risk factors for suicide in patients with schizophrenia. Suicidal schizophrenics usually fear further mental deterioration, and they experience either excessive treatment dependence or loss of faith in treatment. Awareness of illness has been reported as a major issue among suicidal schizophrenic patients, yet some researchers argue that insight into the illness does not increase suicide risk. Protective factors play also an important role in assessing suicide risk and should also be carefully evaluated. The neurobiological perspective offers a new approach for understanding self-destructive behavior among patients with schizophrenia and may improve the accuracy of screening schizophrenics for suicide. Although, there is general consensus on the risk factors, accurate knowledge as well as early recognition of patients at risk is still lacking in everyday clinical practice. Better knowledge may help clinicians and caretakers to implement preventive measures.This review paper is the results of a joint effort between researchers in the field of suicide in schizophrenia. Each expert provided a brief essay on one specific aspect of the problem. This is the first attempt to present a consensus report as well as the development of a set of guidelines for reducing suicide risk among schizophenia patients.

Positive symptomatology and source-monitoring failure in schizophrenia - an analysis of symptom-specific effects

Recent research has suggested that certain positive symptoms in patients with schizophrenia are linked to self monitoring/reality-monitoring deficits. We wished to investigate the association between such deficits and three specific symptoms: hallucinations, delusions and thought disorganisation. Forty patients with schizophrenia and 40 normal controls were administered a source-monitoring task. Twenty-four items were produced, either verbally by the experimenter, or verbally by the subject, or presented as pictures. Then, subjects were read a recognition list including the produced target items mixed with distractors. They were required to recognise the target items and to remember their source of production. The pattern of memory deficits has previously been reported (Brébion, G., Smith, M., Gorman, J., Amador, X., 1997. Discrimination accuracy and decision biases in different types of reality monitoring in schizophrenia. Journal of Nervous and Mental Disease 185, 247-253). The current analyses focussed on the false recognition of distractors, and on the errors in the source attribution of the recognised target items. Results showed that higher hallucination scores were associated with an increased tendency towards false recognition of non-produced items. In addition, hallucinators were more prone than control subjects to misattribute to another source the items they had produced themselves. Furthermore, hallucinators and delusional patients were more prone than the other patients to report that spoken items had been presented as pictures. This latter finding suggests that both hallucinations and delusions are associated with confusion between imagined and perceived pictures. Our previous report stated that only one of the three investigated types of response bias was associated with global positive symptomatology. However, this finer-grained analysis revealed that the three of them were in fact associated with hallucinations and/or delusions. On the other hand, thought disorganisation appeared to be independent from these mechanisms.

Racial differences in the diagnosis of psychosis

In clinical populations, it has been reported that African-American patients are more likely to receive a diagnosis of schizophrenia than similar Caucasian patients. Factors contributing to this racial discrepancy are poorly defined. The authors examined the hypothesis that racial differences in severity of first-rank symptoms of schizophrenia contribute to this diagnostic difference. Patients were recruited as part of the DSM-IV Field Trial for Schizophrenia and Other Psychotic Disorders, and evaluated using a structured rating instrument. Symptom and diagnostic comparisons were performed between black and white patients. Black patients were significantly more likely than white patients to be diagnosed with schizophrenia and less likely with psychotic depression. Racial differences in symptom profiles were observed with black patients demonstrating more severe psychotic symptoms, in general, and first-rank symptoms, specifically. There were no racial differences in rates of affective syndromes or severity of affective symptoms. Racial disparity in diagnosis of psychotic patients may be in part secondary to more severe first-rank symptoms in black patients, causing clinicians to stray from DSM-III-R criteria.

PSYCHOPATHOLOGIC DOMAINS AND INSIGHT IN SCHIZOPHRENIA

The earlier conceptualization of positive and negative symptom topologies for schizophrenia has given way to more complex models that propose three-and-four dimensions of psychopathology. These constructs may relate to neurobiologic heterogeneity and discrete symptom clusters have been shown to have distinct anatomical and cognitive correlates. Insight is an excellent example and the understanding of insight at psychopathologic and cognitive levels has facilitated new approaches to treatment and enhanced medication compliance.

Source monitoring impairments in schizophrenia: characterisation and associations with positive and negative symptomatology

This article describes a consistent pattern of the associations between source monitoring failure and clinical symptomatology in schizophrenia. The associations with positive symptoms in this sample have been reported previously, but not the associations with negative symptoms. Forty patients with schizophrenia were administered several memory tasks including free recall of lists of words, recognition and source memory. Various memory errors assumed to stem from source monitoring failure were derived. They include intrusions and recall of words from previous lists in free recall, false recognitions, and confusion with regard to the source of the stimuli. We studied the associations of these memory errors with positive symptoms and with a broad range of negative symptoms. All the memory errors were positively associated with at least one positive symptom. On the other hand, these errors were inversely associated with certain negative symptoms reflecting lack of emotion or lack of social interactions. Thus positive and negative symptomatology appear to have opposite links to the source monitoring errors observed in patients with schizophrenia. Cognitive mechanisms leading to different types of source monitoring errors and possibly to the formation of positive symptoms are discussed.

The deficit syndrome in the DSM-IV Field Trial: I. Alcohol and other drug abuse

Drug abuse is common in schizophrenia. Previous studies suggested patients with the deficit syndrome have a lower risk of drug abuse than do patients without deficit features. We distinguished deficit and nondeficit groups in the DSM-IV Field Trial dataset, and compared the two groups relative to current and lifetime (worst ever) severity of alcohol, cannabis, and other drugs of abuse. Deficit syndrome patients had a lower severity of current use of alcohol and other drugs, but the two groups did not differ significantly relative to cannabis use. Deficit patients also had less severe lifetime use of all three classes of drugs. These findings could not be attributed to differences between the deficit and nondeficit groups in demographics, severity of psychotic symptoms, chronicity of illness, or the quality of information available for the two groups. Deficit categorization and drug abuse were independently associated with poor level of function. Negative symptoms broadly defined were weaker predictors of drug abuse than was the deficit/nondeficit categorization. These findings further support the validity of the deficit syndrome of schizophrenia. Within schizophrenia, groups with relatively high or low risk for substance abuse can be identified.

Visual backward-masking deficits in schizophrenia: relationship to visual pathway function and symptomatology

Patients with schizophrenia have information processing deficits which can be measured using visual backward-masking (VBM) tasks. There are two types of visual pathways: transient and sustained. The former is more sensitive to low spatial frequency (LSF) and the latter to high spatial frequency (HSF) stimuli. It has been hypothesized that the VBM deficit in schizophrenia is due to an overactive transient channel response to the mask. To examine this hypothesis, patients with schizophrenia and comparison volunteers were tested on a traditional backward-masking task as well as on tasks that altered the mask to bias stimulation toward transient (LSF) or sustained (HSF) channels. Medication effects and relationship to symptomatology were also examined. Patients with schizophrenia showed a significant deficit on the traditional backward-masking task and were also significantly impaired on the LSF- and HSF-masking tasks, though a differential deficit was not found on the latter two tasks. A U-shaped function, indicative of masking by interruption, was found on the LSF- and HSF-masking tasks. Masking performance was not altered when the same patients were tested on and off medication, and performance was related to positive and negative symptoms. In conclusion, the finding of a deficit in patients with schizophrenia on tasks producing a U-shaped function suggests that an aberrant transient response to the mask is producing increased interruption of the sustained response to the target.

Memory impairment and schizophrenia: the role of processing speed

A link between slowing of processing speed and cognitive disorders, including memory, has repeatedly been found in research on aging, and suggested in other cognitively impaired populations. We tested the hypothesis that a link between memory impairment and slowing of processing speed would also be observed in schizophrenia. Forty-four schizophrenic patients and 40 normal controls were administered a memory task involving free recall and recognition. Processing speed was assessed by the Digit Symbol Substitution Test. Working memory span was assessed as well. The measure of processing speed was consistently correlated with the various memory measures in patients, including efficiency of encoding. These correlations remained significant, or tended to be significant, when working memory span was partialled out. Memory deficits observed in schizophrenia may thus be partly accounted for by a slowing of processing speed. It is suggested that research on cognitive deficits in this and other mental diseases focus more on processing speed.

Anxiety and substance use comorbidity among inpatients with schizophrenia

OBJECTIVE To determine the association between lifetime anxiety symptoms and anxiety disorders and substance use disorders among patients with schizophrenia. METHOD Participants were 184 inpatients with schizophrenia at the Schizophrenia Research Unit (SRU) at the New York State Psychiatric Institute (NYSPI). Multivariate logistic regression analyses were used to determine the relationship between specific anxiety symptoms and anxiety disorders and substance use disorders among inpatients with schizophrenia. RESULTS Anxiety symptoms and anxiety disorders were prevalent among 31.5% of the sample. Panic attacks were associated with a significantly increased odds (OR=7.4 (1.2, 47.1)) of comorbid alcohol or substance use disorders (lifetime). This association was specific to panic attacks and persisted after adjusting for differences in sociodemographic characteristics and comorbid anxiety symptoms and anxiety disorders. CONCLUSIONS These findings are consistent with and extend previous data by providing evidence of an association between panic attacks and increased likelihood of substance use disorders among inpatients with schizophrenia. Future studies that determine the nature of this relationship, the sequence of symptom onsets, and examine whether treatment of anxiety can influence the onset or outcome associated with substance use are needed.

Odor Identification, Eye Tracking and Deficit Syndrome Schizophrenia

BACKGROUND Deficit syndrome (DS) schizophrenia patients have smooth pursuit eye movement (SPEM) dysfunction. We examined if they also had smell identification deficits, since social affiliation is related to olfaction in other mammals. METHODS Sixty-seven patients had DS assessments: 31 patients had SPEM and 50 had Smell Identification Test (SIT) assessments, and 14 patients had both measurements. RESULTS DS patients had worse SPEM and SIT performance than the non-DS patients. Areas under the receiver-operator characteristic (ROC) curves for SIT and SPEM were both fairly accurate in identifying the DS. The odds ratio (OR) for the DS for impaired versus normal SPEM was 6.21 (95% confidence interval [CI]: 1.21, 32.25) and for microsmia versus normosmia was 10.4 (95% CI: 1.23, 88.18). Further analyses showed that the association of SIT with both SPEM and the DS could account for the SPEM-DS association. CONCLUSIONS We found a strong association between the DS and SIT scores suggesting that the neural substrates of olfaction may be related to social affiliation in humans, as they are in other mammals. These data further support the notion that the DS defines a homogeneous subgroup of schizophrenia patients and further suggest that dysfunction in the neural circuitry of olfaction may contribute to its pathophysiology.