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C N Stefanis

Publications and source records attributed to C N Stefanis.

At least 19 recordsLinked to original sources
PubMed2005

Occupational abilities and performance scale--reliability-validity assessment factor analysis.

BACKGROUND: This article presents a study of the Occupational Abilities and Performance Scale (OAPS), developed for administration to schizophrenic patients. The reliability and validity of the OAPS has been evaluated. METHOD: A total of 174 schizophrenic patients who participated in the Psychosocial and Vocational Rehabilitation Unit (PVRU) of the University Mental Health Research Institute (UMHRI) in Athens were assessed. The OAPS is conducted at entry and after 18 months, when the client has completed training. RESULTS: The results of the reliability analysis showed very good internal consistency, with high split-half reliability as well as test-retest reliability and inter-rater agreement. The scale was also found to have good predictive validity, as well as concurrent validity. Finally, factor analysis with principal components extraction method was performed in order to assess the construct validity of the scale. CONCLUSIONS: The results of factor analysis supported the conclusion of good reliability and validity of the OAPS and revealed the existence of five components, each correlated with a set of the original items.

Adult↗
PubMed2005

Suicide in cyprus 1988-1999.

Suicide is a universally observed human behavior related to bio-psychological, social and cultural factors. The aim of the present study was to examine suicide in Cyprus, an island that has known many civilizations and cultures. All completed suicide cases in the Christian population of Cyprus during the years 1988-1999 were included in the study and they were analyzed according to age, gender, reported reasons for suicide and suicide methods. The main results indicate that: 1. The mean age-standardized suicide rate is the lowest in Europe, in males (3.08/100,000) and also in females (1.05/100,000). 2. Mean suicide rates increase significantly with age in males only. 3. Female suicide rates are highest in the 15-24 age group. 4. Statistically significant rising trends of male and female suicide rates in the all-ages group. 5. Suicide methods were mostly violent. Among males, the most common methods were poisoning, firearms-explosives, and hanging, while in females, jumping, hanging and poisoning. 6. Mental disorders, physical illness, interpersonal and financial problems were the main reported reasons for suicide. The epidemiological characteristics of suicide in Cyprus might be attributed to a combined effect of social and cultural factors and probably reflect influences from countries to which Cyprus is ethnically, historically or geographically related.

Adolescent↗
PubMed2004

Is the excess risk of psychosis-like experiences in urban areas attributable to altered cognitive development?

BACKGROUND: Rates of psychotic disorder and related attenuated psychotic experiences are higher in urban areas. We examined to what degree differences between urban and rural areas could be attributed to differences in cognitive development. METHOD: Scores on the nine subscales of the schizotypal personality questionnaire (SPQ) as well as IQ and specific neuropsychological functions of memory and attention were assessed in a representative sample of 943 young army conscripts from the 49 counties of Greece. RESULTS: Young men from urban areas had higher scores on the SPQ subscale Odd beliefs/magical thinking (OR = 1.99, 95% CI: 1.42, 2.78), but lower scores on Excessive social anxiety (OR = 0.63, 95 % CI: 0.49, 0.81) and No close friends (OR = 0.42, 95% CI: 0.29, 0.62). Adjustment for demographic factors, IQ and specific neuropsychological functions did not change the results. When the lower scores on Excessive social anxiety and No close friends were taken into account, the differences on the Odd beliefs/magical thinking subscale became even more pronounced (OR = 2.33, 95% CI: 1.56, 3.49). CONCLUSIONS: Young men from urban areas are socially more competent, but display higher levels of positive psychotic experiences, which are not mediated by lower IQ or higher levels of neuropsychological impairment.

Adolescent↗
PubMed2004

Early adolescent cannabis exposure and positive and negative dimensions of psychosis.

AIMS: To investigate the effect of exposure to cannabis early in adolescence on subclinical positive and negative symptoms of psychosis. DESIGN: Cross-sectional survey in the context of an ongoing cohort study. SETTING: Government-supported general population cohort study. PARTICIPANTS: A total of 3500 representative 19-year olds in Greece. MEASUREMENTS: Subjects filled in the 40-item Community Assessment of Psychic Experiences, measuring subclinical positive (paranoia, hallucinations, grandiosity, first-rank symptoms) and negative psychosis dimensions and depression. Drug use was also reported on. FINDINGS: Use of cannabis was associated positively with both positive and negative dimensions of psychosis, independent of each other, and of depression. An association between cannabis and depression disappeared after adjustment for the negative psychosis dimensions. First use of cannabis below age 16 years was associated with a much stronger effect than first use after age 15 years, independent of life-time frequency of use. The association between cannabis and psychosis was not influenced by the distress associated with the experiences, indicating that self-medication may be an unlikely explanation for the entire association between cannabis and psychosis. CONCLUSIONS: These results add credence to the hypothesis that cannabis contributes to the population level of expression of psychosis. In particular, exposure early in adolescence may increase the risk for the subclinical positive and negative dimensions of psychosis, but not for depression.

Adolescent↗
PubMed2003

Active eye fixation performance in 940 young men: effects of IQ, schizotypy, anxiety and depression.

A total of 940 young men performed a task in which they actively maintained fixation for 50 s in three conditions: a). on a visual target, b). on a visual target while distracting targets appeared briefly on the periphery and c). with no visual target present. The same individuals completed psychometric evaluation tests measuring IQ, schizotypy and current state-dependent psychopathology. The proportion of fixation time decreased and saccade frequency increased in condition b compared wih condition a, and sequentially in condition c compared with condition b. A trend towards a decrease in proportion of fixation time and increase in saccade frequency was found as the subjects maintained fixation during the task and this time-dependent deterioration of performance was again most pronounced in condition c, less so in condition b and absent in condition a. Psychometric test scores were significantly correlated with fixation performance in the population. Worse performance in all three fixation conditions was observed for individuals with lower IQ scores. A deterioration of fixation performance with time in condition b was correlated with disorganization characteristics of schizotypy, suggesting that these individuals had difficulty maintaining active fixation in the presence of increased inhibitory load. A connection of such a difficulty with the frontal lobes and their role in the control of voluntary inhibitory functions is discussed.

Adolescent↗
PubMed2003

Effects of direction on saccadic performance in relation to lateral preferences.

A sample of 676 healthy young males performed visually guided saccades and antisaccades and completed the Porac-Coren questionnaire measuring lateral preferences. There was no difference in mean latency between rightward versus leftward saccades or for saccades executed in the left versus right hemispace. There was also no right/left asymmetry for individuals with left or right dominance as assessed by the lateral preferences questionnaire. The same results were observed for the latency of antisaccades and for the error rate in the antisaccade task. Finally, we did not confirm any substantial subpopulation of individuals with idiosyncratic left/right latency asymmetries that persisted both in the saccade and antisaccade task. These results suggest that neither latency nor antisaccade error rate are good indicators of lateral preferences in these tasks. Other oculomotor tasks might be more sensitive to hemifield differences, or cerebral hemispheric asymmetry is not present at the level of cortical organization of saccades and antisaccades.

Adult↗
PubMed2002

The antisaccade task in a sample of 2,006 young males. II. Effects of task parameters.

Antisaccade performance was investigated in a sample of 2,006 young males as part of a large epidemiological study investigating psychosis proneness. This report summarizes the effects of task parameters on performance using a sample of 55,678 antisaccade trials collected from a subpopulation of 947 individuals. Neither the amplitude nor the latency of an error prosaccade in the antisaccade task was correlated with the latency of the ensuing corrective antisaccade that almost always followed an error. However, the latency of the corrective antisaccade decreased with increasing stimulus distance. Concerning the effects of specific task parameters, trials with stimuli closer to the central fixation point and trials preceded by shorter fixation intervals resulted in more errors and longer latencies for the antisaccades. Finally, there were learning and fatigue effects reflected mainly in the error rate, which was greater at the beginning and at the end of the 5-min task. We used a model to predict whether an error or a correct antisaccade would follow a particular trial. All task parameters were significant predictors of the trial outcome but their power was negligible. However, when modeled alone, response latency of the first movement predicted 40% of errors. In particular, the smaller this latency was, the higher the probability of an error. These findings are discussed in light of current hypotheses on antisaccade production mechanisms involving mainly the superior colliculus.

Adolescent↗
PubMed2002

The antisaccade task in a sample of 2,006 young men. I. Normal population characteristics.

A population of 2,075 young men aged 18-25 years selected from the conscripts of the Greek Air Force performed an antisaccade task as part of a prospective study for the identification of risk factors in the development of psychoses. The aim of this study, which is ongoing, is to follow this population and investigate the possible predictive value of oculomotor, cognitive, and psychometric factors for the development of psychosis and other psychiatric conditions. In this report we present data concerning the antisaccade task in this population. We measured performance indices, including the percentage of errors (PE), the latencies of different eye movement responses (latency for correct antisaccades, errors, corrections), and performance in perseveration-prone trials. These indices were also evaluated with respect to IQ (measured by the Raven progressive matrices test) and educational level. Mean PE was 23%, with 17% variance. This large variance is of particular importance whenever the detection of a putative deviant behavior is explored. As mean latency of the first eye movement decreased, the PE increased, as did the latency variance. While the negative correlation between percentage of error and mean latency is well established, the relationship of the latency variability of the first response to error production has not been studied before. Thus, optimal performance appears to require both an intermediate mean latency and a small variability. Furthermore, performance seems to be affected by IQ (the higher the IQ score, the lower the percentage of errors). This report offers an analysis of the interindividual variation in the performance of the antisaccade task and discusses some of the sources of this variation.

Adolescent↗
PubMed2002

Attitudes about schizophrenia from the pilot site of the WPA worldwide campaign against the stigma of schizophrenia.

BACKGROUND: A series of surveys were conducted to assess the attitudes of the public, and other groups, toward those with schizophrenia. The aim of these surveys was to aid in the planning and evaluation of the WPA anti-stigma initiative in Alberta, Canada. METHOD: A questionnaire was devised and administered via telephone to over 1,200 individuals in three Alberta cities, and in paper and pencil format to 40 members of the Schizophrenia Society of Alberta and 67 medical students. RESULTS: In contrast to some earlier findings, "loss of mind" was rated to be more disabling than any other handicapping condition. In general, respondents showed a relatively sophisticated understanding of schizophrenia and a higher level of acceptance than might have been predicted. Nonetheless, this acceptance was not as high for situations where closer personal contact was likely, and fears of dangerousness continue to be associated with schizophrenia. The majority of respondents, however, felt that treatment aided those with schizophrenia, expressed support for progressive programmes for the mentally ill, and stated that they would be willing to pay higher taxes so that programming could be improved. CONCLUSIONS: The results do not support the utility of a broad approach for an anti-stigma campaign, but rather suggest a more specific focus, such as perceived dangerousness.

Adolescent↗
PubMed2002

Self-esteem, social adjustment and suicidality in affective disorders.

Self-esteem (SE) and social adjustment (SA) are often impaired during the course of affective disorders; this impairment is associated with suicidal behaviour. The aim of the present study was to investigate SE and SA in unipolar or bipolar patients in relation to demographic and clinical characteristics, especially the presence of suicidality (ideation and/or attempt). Forty-four patients, 28 bipolar and 16 unipolar, in remission for at least 3 months, and 50 healthy individuals were examined through a structured clinical interview. SE and SA were assessed by the Rosenberg self-esteem scale and the social adjustment scale, respectively. The results have shown that bipolar patients did not differ from controls in terms of SE, while unipolar patients had lower SE than bipolars and controls. No significant differences in the mean SA scores were found between the three groups. Suicidality during depression was associated only in bipolar patients with lower SE at remission; similar but not as pronounced was the association of suicidality with SA. It is concluded that low SE lasting into remission seems to be related to the expression of suicidality during depressive episodes of bipolar patients, while no similar pattern is evident in unipolar patients.

Adult↗
PubMed2002

Evidence that three dimensions of psychosis have a distribution in the general population.

BACKGROUND: The aims of the study were: first to examine, using clinical symptoms of patients as a template, whether the correlated but independent dimensions of positive, negative and depressive symptoms that have been identified in clinical psychosis, also have a distribution as non-clinical experiences in the general population; and second, to establish to what degree population variation in experience of positive and negative features of psychosis is actually independent of experience of depression. METHOD: In a representative population sample of 932 young men, we measured experiences of positive, negative and depressive features of psychosis, using a 40-item self-report instrument. Confirmatory factor analysis was used to compare the fit of hypothesized one-, two- and three-factor solutions. RESULTS: A three-factor model of separate depressive, positive and negative dimensions provided a better fit to the data than either a two-factor or unidimensional model. All three dimensions were correlated with each other, but also showed good discriminant validity in relation to established scales, confirming their relative independence. CONCLUSION: The data suggest that the correlated dimensions of clinical psychosis also have a distribution in the general population, and that depressive symptoms may form an integral part of psychosis-like experiences in the general population.

Adolescent↗
PubMed2002

Higher scores of self reported schizotypy in healthy young males carrying the COMT high activity allele.

The gene for COMT is located on chromosome 22q11, an area that has been implicated in the pathogenesis of schizophrenia through linkage studies and through the detection of deletions in schizophrenics and velocardiofacial syndrome patients that often present psychotic symptomatology. Additionally catechol-O-methyl transferase activity has been found increased in schizophrenia and a functional polymorphism in the COMT gene itself has been associated with the disease, as well as with aggression in patients. We tested the hypothesis that COMT genotype for the functional Val158Met might contribute to the variance of self reported schizotypy and aggression scores in the normal population. We genotyped 379 healthy 18- to 24-year-old male individuals who had completed the PAS, SPQ and AQ questionnaires. Our results showed that self-reported schizotypy scores in both questionnaires were significantly related to COMT genotype (P = 0.028 for the PAS and P = 0.015 for the SPQ) with individuals homozygous for the high activity allele showing the highest scores. No significant differences were detected for AQ scores. We conclude that the COMT genotype for the functional Val158Met polymorphism is correlated to self-reported schizotypy in healthy males. This finding is in the same direction as reported findings on schizophrenia and it adds to the list of evidence that COMT or a nearby gene in linkage disequilibrium is involved in the pathogenesis of the disease.

Adolescent↗
PubMed2001

GABA-A receptor beta3 and alpha5 subunit gene cluster on chromosome 15q11-q13 and bipolar disorder: a genetic association study.

There is accumulated evidence that the genes coding for the receptor of gamma aminobutyric acid (GABA), the most important inhibitory neurotransmitter in the CNS, may be involved in the pathogenesis of affective disorders. In a previous study, we have found a genetic association between the GABA-A receptor alpha5 subunit gene locus (GABRA5) on chromosome 15q11-of 13 and bipolar affective disorder. The aim of the present study was to examine the same subjects to see if there exists a genetic association between bipolar affective disorder and the GABA receptor beta3 subunit gene (GABRB3), which is located within 100 kb from GABRA5. The sample consisted of 48 bipolar patients compared to 44 controls (blood donors). All subjects were Greek, unrelated, and personally interviewed. Diagnosis was based on DSM-IV and ICD-10 criteria. The marker used was a dinucleotide (CA) repeat polymorphism with 12 alleles 179 to 201 bp long; genotyping was successful in all patients and 43 controls. The distribution of GABRB3 genotypes among the controls did not deviate significantly from the Hardy-Weinberg equilibrium. No differences in allelic frequencies between bipolar patients and controls were found for GABRB3, while this locus and GABRA5 did not seem to be in significant linkage disequilibrium. In conclusion, the GABRB3 CA-repeat polymorphism we investigated does not present the observed association between bipolar affective illness and GABRA5. This could be due to higher mutation rate in the GABRB3 CA-repeat polymorphism, but it might also signify that GABRA5 is the gene actually associated with the disease.

Alleles↗
PubMed2001

Cytokine serum levels, autologous mixed lymphocyte reaction and surface marker analysis in never medicated and chronically medicated schizophrenic patients.

A number of immunological parameters were studied in 82 DSM-III-R diagnosed schizophrenic patients (53 first drug-naive and 29 medicated chronic patients) as well as 62 healthy blood donors. The serum levels of interleukin-2 (IL-2), interleukin-1 beta (IL-1beta) and tumour necrosis factor-alpha (TNF-alpha) were measured and correlated with cellular immunity, as assessed by the autologous mixed lymphocyte reaction (AMLR). T lymphocyte subsets were also examined. The above immune parameters were reassessed in a subgroup of 11 first-episode, drug-naive patients 1month after neuroleptic medication. IL-2 serum levels were significantly lower, and IL-1beta and TNF-alpha were significantly higher in schizophrenic patients compared with healthy donors (P<0.001); no significant difference was observed between the two patient groups (medicated and not medicated). Abnormal cytokine serum levels were associated with decreased AMLR responses in vitro. Increased percentages of activated CD4+ and CD16+ natural killer cells, as well as cells expressing ICAM-1 adhesion molecules and IL-2 specific receptors, were detected in the patients. Immunophenotype studies revealed a higher percentage of cells expressing IL-2 receptors in medicated chronic schizophrenic patients compared with drug-naive patients. The abnormal cytokine production in vivo, along with the low AMLR responses in vitro, and the high percentage of activated CD4+ lymphocytes presented in this study suggest alterations in the immune system of schizophrenic patients (medicated or not medicated) consistent with immune activation.

Adolescent↗
PubMed2001

An early transient 40 Hz activity discriminates a following pro-saccade from a no-move and anti-saccade choice.

We studied the oscillatory activity of the scalp-recorded EEG in healthy humans performing a task that required a particular eye-movement response choice according to the shape of a visual target. We observed a significant stimulus-aligned activity at the 40 Hz frequency band 100 ms after the appearance of the target only when that target was the end point for the subsequent eye movement (pro-saccade). This activity was most prominent over the central-parietal area of the right hemisphere. When the target indicated a movement to the opposite direction (anti-saccade) or indicated that no movement was required (no-move), this 40 Hz activity was nearly absent. This difference in activity between the pro-saccade and the other two tasks was evident in the single subject ERPs for four of the six subjects studied. In contrast, the movement-aligned 40 Hz activity for the pro-saccade and anti-saccade was almost identical. We speculate that this early stimulus-aligned 40 Hz activity might reflect a fast transformation of a visual stimulus to a motor response (eye movement) that can be performed for the pro-saccade task where stimulus-response compatibility is strong compared to the anti-saccade and no-move tasks. The movement-aligned 40 Hz activity might be related to the motor response preparation per se. We conclude that this task specific transient oscillatory activity could be used as a probe in the study of the temporal dynamics of visuomotor transformations.

Analysis of Variance↗
PubMed2001

Relapse prevention in schizophrenia: attitudes of neurologists-psychiatrists.

The overall high relapse rates observed in schizophrenia are attributed to several causes. One important factor influencing satisfactory prevention of relapse is the lack of consistent treatment strategies among medical doctors, especially neurologists-psychiatrists. Nearly one-third of the members of the Hellenic Society of Neurology and Psychiatry were asked to fill in anonymously a structured questionnaire on their treatment attitudes and prescribing tactics regarding schizophrenic patients both after the first schizophrenic episode and after multiple episodes. The majority of Greek neurologists-psychiatrists seem to adopt prescribing habits that approximate the current international standards for prevention of schizophrenic relapse. Their attitudes regarding the treatment and prevention of relapse for the first schizophrenic episode and first relapse are determined from multiple factors. These are: the expected relapse rates after the first episode, the expected prevalence of extrapyramidal side effects following a long-term neuroleptic treatment, the patient's expected treatment compliance after the first episode, the doctor's experience with treating schizophrenics, and lastly the knowledge of current literature on the topic. These results point to the need for continuing education, especially of the younger mental health professionals and those working in the private sector, addressing the issue of the actual risk of developing side effects from the treatment. In due course, benefits could result for everyday psychiatric practice and the patients' compliance with treatment.

Adult↗
PubMed2000

Linkage of mood disorders with D2, D3 and TH genes: a multicenter study.

BACKGROUND: It has been suggested that the dopaminergic system is involved in the pathophysiology of mood disorders. We conducted a multicenter study of families with mood disorders, to investigate a possible linkage with genes coding for dopamine receptor D2, dopamine receptor D3 and tyrosine hydroxylase (TH). METHODS: Twenty three mood disorder pedigrees collected within the framework of the European Collaborative Project on Affective Disorders were analyzed with parametric and non-parametric linkage methods. Various potential phenotypes were considered, from a narrow (only bipolar as affected) to a broad (bipolar+major depressive+schizoaffective disorders) definition of affection status. RESULTS: Parametric analyses excluded linkage for all the candidate genes, even though small positive LOD (Limit of Detection) scores were observed for TH in three families. Non-parametric analyses yielded negative results for all markers. CONCLUSION: The D2 and D3 dopamine receptors were, therefore, not a major liability factor for mood disorders in our sample, whereas TH may play a role in a subgroup of patients.

Bipolar Disorder↗