Psychiatric morbidity in the first-degree relatives of schizophrenic patients

Aggressive behaviour in antipsychotic-naive first-episode schizophrenia patients, their unaffected siblings and healthy controls

AIM

While patients with schizophrenia are more likely to be victims rather than perpetrators of aggressive behaviour, prior research has shown increased rates of aggressive behaviours in these patients that appear very early in the course of illness. We aimed to assess aggression in antipsychotic-naive first-episode schizophrenia patients, their healthy siblings, and controls; and to investigate correlates of aggression in the patients group.

METHODS

Patients (N = 55), siblings (N = 55) and healthy controls (N = 71) were evaluated on Buss and Perry Aggression Questionnaire (AQ), Life History of Aggression (LHA), Barratt Impulsiveness Scale, and Levenson Self-Report Psychopathy Scale. Age, gender and substance use were regarded as covariates, and differences between the three groups were evaluated using analysis of covariance. Hierarchical regression was performed to determine which variables were associated with aggression level in the patients group.

RESULTS

The Tukey multiple comparison test showed that both patients (p < .001) and siblings (p = .023) scored higher on the LHA Aggression than controls. Siblings scored higher than controls (p = .010) for the Anger subscale of the AQ. Patients scored significantly higher than controls in the three impulsiveness dimensions; whereas siblings scored higher than controls in the motor (p = .023) and non-planning (p = .004) dimensions. Multivariate analyses showed that, after controlling for confounders, only attentional impulsiveness (β = .446, p = .0244) and psychopathy traits (β = .359, p = .010) helped predict AQ total scores among patients.

CONCLUSION

Aggression and some of its risk factors including impulsiveness are likely to be trait variables that might provide important vulnerability markers for people at heightened risk of developing psychosis.

Psychiatric morbidity and HIV in female drug dependants in Malaysia

Female drug dependants (n = 171) and controls (n = 1137) were studied to search for psychiatric morbidity in them. The psychiatric morbidity was found to be 36.3% and 6.9%, respectively. The most common psychiatric disorder found was dysthymic disorder followed by adjustment disorder, anxiety disorder and borderline personality disorder. The diagnosis was significantly dependent on the type of drug used (P < 0.001) and HIV seropositivtty status of the patients (P = 0.04). The findings highlight the relationship of the psychiatric morbidity to the HIV status and female drug users.

Risk of schizophrenia in relatives of individuals affected by schizophrenia: A meta-analysis

A meta-analysis was conducted to estimate schizophrenia incidence in first-degree relatives (FDRs) of probands diagnosed with schizophrenia. The aim was to inform future schizophrenia research and improve accuracy of risk communication to patients. Schizophrenia risk in FDRs with 1 or 2 probands with schizophrenia was investigated by conducting a systematic review of cohort and case-control studies with the following criteria: published between 1977 and 2018; reported odds ratios (OR), relative risk (RR) or sufficient raw data to calculate OR or RR; used appropriate diagnostic criteria; and reported systematic proband recruitment and ascertainment of relatives. Studies were obtained via EMBASE and MEDLINE electronic database searches. From an initial 5755 articles, 19 met the inclusion criteria. Mean effect sizes across studies were estimated using random effects methods. Estimates for schizophrenia risk were OR = 7.69 (95% CI 5.11-11.56) for FDRs of one proband with schizophrenia compared to healthy control probands, increasing to OR = 11.11 (95% CI = 1.45-85.02) for FDRs with two probands with schizophrenia. These findings support the existing literature suggesting significant genetic liability for schizophrenia. The results can be used to educate individuals with a family history of schizophrenia about their risk.

Cognitive functioning associated with stimulant use in patients with non-affective psychosis, their unaffected siblings and healthy controls

BACKGROUND

Little is known about the effect of stimulant use (amphetamines, cocaine, ecstasy) on cognitive functioning in schizophrenia patients. The current study examined (1) whether recency and frequency of stimulant use is associated with cognitive functioning and (2) whether these associations differ between psychotic patients, their unaffected siblings and controls.

METHOD

Participants completed a comprehensive cognitive test battery. Stimulant use was assessed by urinalysis and by the Composite International Diagnostic Interview (CIDI). Using random effects regression models, the main effects of Stimulant Use and the interaction with Diagnostic Status on cognitive functioning were assessed.

RESULTS

The interaction term between Stimulant Use and Diagnostic Status was not significant for any of the cognitive outcome variables, indicating similar effects of stimulant use in all three groups. Recent stimulant users showed more errors deficit in verbal learning in comparison to never users (Cohen's d = -0.60, p < 0.005). Lifetime frequent stimulant use was significantly associated with worse immediate and delayed verbal recall, working memory and acquired knowledge (Cohen's d = -0.22 to -0.29, p < 0.005). Lifetime infrequent stimulant use was not associated with significant cognitive alterations in comparison to never use.

CONCLUSIONS

The presence of cognitive deficits associated with lifetime stimulant use is dependent on the frequency of use, with no observed deficits in infrequent users and modest negative effects in frequent users.

A controlled family study of cannabis users with and without psychosis

BACKGROUND

Cannabis is one of the most highly abused illicit drugs in the world. Several studies suggest a link between adolescent cannabis use and schizophrenia. An understanding of this link would have significant implications for legalization of cannabis and its medicinal value. The present study aims to determine whether familial morbid risk for schizophrenia is the crucial factor that underlies the association of adolescent cannabis use with the development of schizophrenia.

METHODS

Consecutively obtained probands were recruited into four samples: sample 1: 87 non-psychotic controls with no drug use; sample 2: 84 non-psychotic controls with cannabis use; sample 3: 32 patients with a schizophrenia spectrum psychosis with no drug use; sample 4: 76 patients with schizophrenia spectrum psychosis with cannabis use. All cannabis using subjects used this drug during adolescence, and no other substance, with the exception of alcohol. Structured interviews of probands and family informants were used to obtain diagnostic information about probands and all their known relatives.

RESULTS

There was an increased morbid risk for schizophrenia in relatives of the cannabis using and non-using patient samples compared with their respective non-psychotic control samples (p=.002, p<.001 respectively). There was no significant difference in morbid risk for schizophrenia between relatives of the patients who use or do not use cannabis (p=.43).

CONCLUSIONS

The results of the current study suggest that having an increased familial morbid risk for schizophrenia may be the underlying basis for schizophrenia in cannabis users and not cannabis use by itself.

A resting-state functional magnetic resonance imaging study on the first-degree relatives of persons with schizophrenia

In this study, resting state fMRI images and BOLD signals were recorded from 13 first-degree relatives of schizophrenic patients and 13 healthy controls. The data were analyzed with the ReHo approach after realignment, registration, and normalization in statistical parametric mapping 2 (SPM2). A two-sample t-test was used to analyze the ReHo differences between first-degree relatives and healthy controls in a voxel by voxel manner. A combined threshold of p < 0.005 and number of voxels >5 was designated as statistically significant. To evaluate cognitive deficits in first-degree relatives, attention/vigilance and verbal/visual memory were measured. Significant impairments in attention were observed in first-degree relatives compared to healthy controls. Significant abnormalities in ReHo were observed in resting brain in first-degree relatives. Decreased ReHo was found to be distributed over the bilateral middle frontal, middle temporal, cingulate gyrus and cerebellar tonsil; the left inferior frontal gyrus, inferior parietal lobule and dorsolateral prefrontal cortex; the right superior frontal gyrus and dorsolateral prefrontal cortex. Increased ReHo was found to be distributed in the right precuneus and superior temporal gyrus. These changes in ReHo suggest abnormality in the resting state brain function of first-degree relatives of schizophrenic patients and may be early signs for the development of schizophrenia.

Role of cannabis and endocannabinoids in the genesis of schizophrenia

RATIONALE

Cannabis abuse and endocannabinoids are associated to schizophrenia.

OBJECTIVES

It is important to discern the association between schizophrenia and exogenous Cannabis sativa, on one hand, and the endogenous cannabinoid system, on the other hand.

RESULTS

On one hand, there is substantial evidence that cannabis abuse is a risk factor for psychosis in genetically predisposed people, may lead to a worse outcome of the disease, or it can affect normal brain development during adolescence, increasing the risk for schizophrenia in adulthood. Regarding genetic predisposition, alterations affecting the cannabinoid CNR1 gene could be related to schizophrenia. On the other hand, the endogenous cannabinoid system is altered in schizophrenia (i.e., increased density of cannabinoid CB1 receptor binding in corticolimbic regions, enhanced cerebrospinal fluid anandamide levels), and dysregulation of this system can interact with neurotransmitter systems in such a way that a "cannabinoid hypothesis" can be integrated in the neurobiological hypotheses of schizophrenia. Finally, there is also evidence that some genetic alterations of the CNR1 gene can act as a protectant factor against schizophrenia or can induce a better pharmacological response to atypical antipsychotics.

CONCLUSIONS

Cannabis abuse is a risk factor for psychosis in predisposed people, it can affect neurodevelopment during adolescence leading to schizophrenia, and a dysregulation of the endocannabinoid system can participate in schizophrenia. It is also worth noting that some specific cannabinoid alterations can act as neuroprotectant for schizophrenia or can be a psychopharmacogenetic rather than a vulnerability factor.

Elevated rates of substance use disorders in non-psychotic siblings of individuals with schizophrenia

BACKGROUND

Individuals with schizophrenia use psychoactive substances more frequently than the general population. The genetic vulnerability to develop schizophrenia may also increase risk for the development of substance use disorders. We examine this hypothesis by assessing the rates of substance use disorders and nicotine use in non-psychotic siblings of individuals with schizophrenia.

METHODS

Participants included 59 individuals with DSM-IV schizophrenia, 53 of their siblings, 80 community controls, and 75 of their siblings. Statistical regression was used to assess the rates of substance use disorders and nicotine use in study participants while controlling for age, gender, lifetime diagnosis of a mood or anxiety disorder, and a family history of substance use disorder.

RESULTS

Individuals with schizophrenia and their non-psychotic siblings reported higher rates of alcohol and cannabis use disorders and nicotine use when compared to siblings of comparison subjects.

CONCLUSIONS

The vulnerability to develop schizophrenia may also extend to substance use disorders. Future research is needed to investigate the neurobiological basis of increased substance use in non-psychotic siblings and the psychosocial mechanisms that may contribute to increased substance use in non-psychotic siblings.

Basal ganglia shape abnormalities in the unaffected siblings of schizophrenia patients

BACKGROUND

Abnormalities of basal ganglia structure in schizophrenia have been attributed to the effects of antipsychotic drugs. Our aim was to test the hypothesis that abnormalities of basal ganglia structure are intrinsic features of schizophrenia by assessing basal ganglia volume and shape in the unaffected siblings of schizophrenia subjects.

METHOD

The study involved 25 pairs of schizophrenia subjects and their unaffected siblings and 40 pairs of healthy control subjects and their siblings. Large-deformation, high-dimensional brain mapping was used to obtain surface representations of the caudate, putamen, and globus pallidus. Surfaces were derived from transformations of anatomic templates, and shapes were analyzed using reduced-dimensional measures of surface variability (i.e., principal components and canonical analysis). Canonical functions were derived using schizophrenia and control groups and were then used to compare shapes in the sibling groups. To visualize shape differences, maps of the estimated surface displacement between groups were created.

RESULTS

In the caudate, putamen, and globus pallidus, the degree of shape abnormality observed in the siblings of the schizophrenia subjects was intermediate between the schizophrenia and control subjects. In the schizophrenia subjects, significant correlations were observed between measures of caudate, putamen, and globus pallidus structure and the selected measures of lifetime psychopathology.

CONCLUSIONS

Attenuated abnormalities of basal ganglia structure are present in the unaffected siblings of schizophrenia subjects. This finding implies that basal ganglia structural abnormalities observed in subjects with schizophrenia are at least in part an intrinsic feature of the illness.

Executive function and genetic predisposition to schizophrenia--the Maudsley family study

Executive cognitive impairment has been found in families affected by schizophrenia and is a putative endophenotype. We wished to explore its genetic basis further by studying the association between impairment and genetic loading for schizophrenia. We studied 30 schizophrenia patients with a family history of schizophrenia, 53 of their nonpsychotic first-degree relatives (familial), 32 patients with schizophrenia but no known family history of psychosis, 52 of their first-degree relatives (nonfamilial), and 47 normal controls. They were tested using the National Adult Reading Test (NART), Trails A and B, Verbal fluency tasks, and a computerized version of the Wisconsin Card Sorting Test (WCST). Familial, but not nonfamilial, relatives were impaired on NART, letter fluency, Trails B, and WCST total errors. They were inferior to nonfamilial relatives on letter fluency and Trails A. Both sets of relatives were impaired on Trails B controlling for Trails A, and on WCST categories achieved. There were no significant differences between schizophrenia patients with and without a family history. Our results suggest that executive deficits qualitatively similar to those seen in those with schizophrenia reflect familial susceptibility, even taking early IQ and education into consideration, consistent with a genetic mechanism.

Soluble interleukin 2 receptor levels in families of people with schizophrenia

BACKGROUND

Several authors have reported increased soluble interleukin 2 receptor (sIL2Ralpha) concentrations in schizophrenia. The aim of this work was to examine serum sIL2Ralpha in the first degree relatives of patients with schizophrenia.

METHODS

We sampled 51 first degree relatives of patients with DSM IIIR schizophrenia. These relatives were unaffected by psychosis and included nine fathers, thirteen mothers, seventeen sisters and twelve brothers. They were compared to 126 controls who were not pregnant, had no known autoimmune disorder and no intercurrent illness. Neither the controls, nor their first degree relatives, suffered from a psychotic illness. Serum sIL2Ralpha was analysed using a commercial ELISA preparation (Quantikine sIL2Ralpha immunoassay - R and D Systems, Inc.). We used non-parametric Mann Whitney U test and Spearman correlation throughout. SIL2Ralpha levels were adjusted for higher levels in females and with increasing age.

RESULTS

Adjusted mean sIL2Ralpha values of unaffected siblings, averaged within their families, were higher than controls (n=14, one-tailed p=0.027). There was no difference in sIL2Ralpha values between fathers or mothers and controls following regression for age and sex.

CONCLUSION

Soluble interleukin 2 receptoralpha levels are increased in siblings of patients with schizophrenia.

Cannabis-induced psychosis: a cross-sectional comparison with acute schizophrenia

OBJECTIVE

The existence of cannabis-induced psychosis (CP) remains controversial, partly because of methodological problems. We hypothesize that acute schizophrenia (AS) and CP can have distinct demographic, premorbid and clinical features.

METHOD

We compared 26 patients with CP to 35 with AS, after their cannabis-consumption status was confirmed by repeated urine screens. Patients with CP were assessed after at least 1 week but not more than 1 month of abstinence. Symptoms were evaluated with the Present State Examination (PSE).

RESULTS

In group CP, male gender, expansive mood and ideation, derealization/depersonalization, visual hallucinations, and disturbances of sensorium were more frequent than in group AS. Premorbid schizoid personality traits were more frequently associated to AS and antisocial personality traits to CP.

CONCLUSION

The continuous heavy use of cannabis can induce a psychotic disorder distinct from AS. These two clinical entities share some features but they differ in others.

Defining the schizophrenia phenotype

Schizophrenia is a complex disease with multifactorial etiology. The schizophrenia phenotype has been traditionally defined by chronic psychosis and functional deterioration. However, the boundary of the phenotype is likely to be more extensive than the one defined by chronic psychosis. This is highlighted by the findings of subtle, schizophrenia- like deficits in the nonschizophrenic, first-degree relatives of schizophrenic patients. Subtle clinical signs and symptoms, cognitive impairment particularly in attention and memory, and neurophysiologic deficits such as in sensory gating and smooth-pursuit eye movements all define aspects of the schizophrenia phenotype.

Negative symptoms of familial schizophrenia breed true in unstable (vs. stable) cerebral-ventricle pedigrees

A pattern of negative symptoms associated with a high rate of ongoing brain and ventricular instability has been described in a cohort of schizophrenia spectrum probands (patients with schizophrenia, schizoaffective disorder depressed and bipolar, and psychosis NOS) (Garver, D.L., Nair, T.R., Christensen, J.D., Holcomb, J., Ramberg, J., Kingsbury, S., 1999. Differential patterns of premorbid functioning, symptoms and neuroleptic response in stable and unstable ventricular-volume schizophrenia. Neuropsychopharmacology 20, in press). The present study contrasts the prevalence of negative symptoms in first- and second-degree relatives of probands with unstable ventricle volume (UnsVV) and stable ventricle volume (SVV). One hundred and sixteen first- and second-degree relatives of 10 probands were interviewed using the SANS, the 'Characterization of Course: "Pattern of Symptoms"' [from Comprehensive Assessment of Symptoms and History (CASH)], SCID and SCID-II by interviewers blind to the status of the proband. Thirty-five of the 116 family members met DSM-IV criteria for schizophrenia, SA depressed, 'Cluster A' of the SCID-II (paranoid, schizotypal, schizoid personality disorder), psychosis NOS, or psychotic affective disorder. These 35 family members were defined as falling within a 'schizophrenia spectrum' as described by Farmer, A.E., McGuffin, P., Gottesman, I.I., 1987. Arch. Gen. Psychiatry 44, 634-641, but with the addition of DSM-IV affective psychosis. On that basis, the 35 members were considered 'affected family members' (AFMs). The remaining 81 family members were considered unaffected. The 'predominant symptoms of illness' (during the past 2-3 years) for 25 of the 35 AFMs could be characterized according to the 'Patterns of Symptoms' derived from the CASH. Twenty-five of the 35 AFMs were found to maintain a predominant symptom pattern during the course of illness, which could be characterized according to the 'Pattern of Symptoms' as 'predominantly positive' or 'predominantly negative'. Three of the probands had UnsVV; seven had SVV. Of the 35 AFMs, 11 were related to the UnsVV probands, and 24 were relatives of the SVV probands. The nine rated AFMs of the UnsVV probands showed a trend toward higher SANS scores (7.3 +/- 5.1) (mean +/- s.d.) than the 20 rated AFMs of SVV probands (4.3 +/- 5.1) (p = 0.08) at the time of the interview. Eighty-three per cent (eight of 10) of rated affected pedigree members of the pedigrees delineated by probands with UnsVV probands had a predominantly negative symptom course of illness, and 96% (23 of 24) of rated affected pedigree members of the pedigrees with SVV probands had a predominantly positive symptom course of illness during the preceding 2-3 years (p = 0.002). None of the 12 rated affected pedigree members within pedigrees having UnsVV probands were married at the time of the interview; 45% (14 of 31) of affected pedigree members having SVV probands were married (p = 0.004). A psychiatric disorder, characterized by unstable cerebral ventricles and predominant negative symptoms (including avoidance/failure of marital relationships) appears symptomatically to breed true in pedigrees containing schizophrenia-like illnesses.

Psychiatric morbidity in the first-degree relatives of schizophrenic patients

There is increasing evidence that genetic factors play a role in the etiology of schizophrenic disorders. One thousand eighty-nine first-degree relatives of schizophrenics and 1,137 controls were studied to discover their psychiatric morbidity. Psychiatric morbidity was found in 16.34% of the first-degree relatives (FDR) of schizophrenics (parents, 5.69%; siblings, 7.71%; offspring, 2.94%) as compared to 6.9% in the controls (P < 0.001). Schizophrenia was found in 8.3% of the patient group, which was significantly higher (0.2%) as compared to the controls. Schizoid-schizotypal personality disorder was found in 3.03% of FDRs of the schizophrenic group. Depressive disorder was found in 4.4% and 2.1% in the control and patient group, respectively, which was statistically significant. Morbidity risk of schizophrenia was found in 16.97%, 6.22% and 5.79% of schizophrenia, schizoid-schizotypal personality disorder and depressive disorder, respectively, in the FDR of schizophrenic group.

Covert visual attention in schizophrenia spectrum personality disordered subjects: visuospatial cuing and alerting effects

A recent study observed lateralized deficit in the disengagement of covert visual attention in schizophrenic patients. Subsequent attempts to replicate this finding have had mixed results. Differences in the neuroleptic treatment or other secondary factors associated with schizophrenia are some of the possible reasons for these inconsistent findings. In this study, we examined the ability to shift covert visual attention in neuroleptic-naive, schizophrenia spectrum personality disordered (SSPD; n = 35) subjects and normal controls (n = 34) under a variety of spatial cuing and alerting conditions. We hypothesized that SSPD subjects would have difficulty with disengagement of covert visual attention from an invalidly cued left visual field when the target appeared in the right visual field in comparison to the normal subjects. As predicted, schizophrenia spectrum personality disordered subjects had significantly longer latencies for the right visual field invalid targets than normals (p = .014). Under the remaining cue conditions, spectrum subjects performed normally. Consequently, the cost of left visual field invalid cueing for the right visual field target was significantly higher in spectrum personality subjects than in normals. The cost for the invalid right visual field cue and the benefits of valid cue in both fields were very similar in the two groups. The findings of an asymmetrical deficit in the disengagement and shift of covert visual attention in schizophrenia spectrum subjects are similar to the one's observed in patients with unilateral left hemisphere lesions.