P.P.G. Hodiamont

Internal and external validity of Attention-Deficit Hyperactivity Disorder in a population-based sample of adults

BACKGROUND Follow-up studies of childhood ADHD have shown persistence of the disorder into adulthood, but no epidemiological data are yet available. METHOD ADHD DSM-IV symptoms were obtained by self-report in an adult population-based sample of 1813 adults (aged 18-75 years), that was drawn from an automated general practitioner system used in Nijmegen, The Netherlands. The structure of ADHD symptoms was analysed by means of confirmatory factor analyses. Other data used in this report are the General Health Questionnaire (GHQ-28), information about the presence of three core symptoms of ADHD in childhood, and about current psychosocial impairment. RESULTS The three-factor model that allowed for cross-loadings provided the best fit in the entire sample. This result was replicated across gender and age subsamples. Inattentive and hyperactivity symptom scores were significantly associated with measures of impairment, even after controlling for the GHQ-28. Subjects with four or more inattentive or hyperactive-impulsive symptoms were significantly more impaired than subjects with two, one and no symptoms. The prevalence of ADHD in adults was 1.0% (95% CI 0.6-1.6) and 2.5% (1.9-3.4) using a cutoff of six and four current symptoms respectively, and requiring the presence of all three core symptoms in childhood. CONCLUSIONS These results support the internal and external validity of ADHD in adults between 18 and 75 years. ADHD is not merely a child psychiatric disorder that persists into young adulthood, but an important and unique manifestation of psychopathology across the lifespan.

Content validity, construct validity, and reliability of the WHOQOL-Bref in a population of Dutch adult psychiatric outpatients

In this study, the psychometric properties of a quality of life scale, the WHOQOL-Bref, were examined in a population of 533 Dutch adult psychiatric outpatients. Participants underwent two semistructured interviews in order to obtain Axis-I and II diagnoses, according to DSM-IV. Besides the WHOQOL-Bref they also completed questionnaires for measuring psychopathological symptoms (SCL-90) and perceived social support (PSSS). Scores on 25 of the 26 questions of the WHOQOL-Bref had a good distribution. Similar to previous findings, exploratory factor analysis revealed a four-factor structure. A priori expected associations were found between the domains of the WHOQOL-Bref, on the one hand, and dimensions of the SCL-90 and the PSSS-score, on the other hand, indicating good construct validity. The internal consistency of the four domains of the WHOQOL-Bref ranged from 0.66 to 0.80. Domain scores of the WHOQOL-Bref correlated around 0.92 with the WHOQOL-100 domain scores. Relatively low correlations were found between demographic characteristics (age and sex) and WHOQOL-Bref domain scores. It is concluded that the content validity, construct validity, and the reliability of the WHOQOL-Bref in a population of adult Dutch psychiatric outpatients are good. The WHOQOL-Bref, therefore, is an adequate measure for assessing quality of life at the domain level in a population of adult psychiatric outpatients.

Multisensory integration of emotional faces and voices in schizophrenics

In their natural environment, organisms receive information through multiple sensory channels and these inputs from different sensory systems are routinely combined into integrated percepts. Previously, we reported that in a population of schizophrenics, deficits in audiovisual integration were observed for complex stimuli (auditory and visual syllables), but not for more simple ones (beeps and light flashes). Here, we investigated multisensory integration of emotional information in a group of schizophrenic patients. In Experiment 1, we found a reduced effect of an emotional voice on the categorization of a facial expression. In Experiment 2, the reverse test situation was presented, and, here, we observed an exaggerated effect of a face expression on the categorization of an emotional voice. Results are discussed in the light of current models of multisensory integration and their relevance for schizophrenia.

Audio-visual integration in schizophrenia

Integration of information provided simultaneously by audition and vision was studied in a group of 18 schizophrenic patients. They were compared to a control group, consisting of 12 normal adults of comparable age and education. By administering two tasks, each focusing on one aspect of audio-visual integration, the study could differentiate between a spatial integration deficit and a speech-based integration deficit. Experiment 1 studied audio-visual interactions in the spatial localisation of sounds. Experiment 2 investigated integration of auditory and visual speech. The schizophrenic group performed as the control group on the sound localisation task, but in the audio-visual speech task, there was an impairment in lipreading as well as a smaller impact of lipreading on auditory speech information. Combined with findings about functional and neuro-anatomical specificity of intersensory integration, the data suggest that there is an integration deficit in the schizophrenic group that is related to the processing of phonetic information.

Audiovisual emotion recognition in schizophrenia: Reduced integration of facial and vocal affect

Since Kraepelin called dementia praecox what we nowadays call schizophrenia, cognitive dysfunction has been regarded as central to its psychopathological profile. Disturbed experience and integration of emotions are, both intuitively and experimentally, likely to be intermediates between basic, non-social cognitive disturbances and functional outcome in schizophrenia. While a number of studies have consistently proven that, as part of social cognition, recognition of emotional faces and voices is disturbed in schizophrenics, studies on multisensory integration of facial and vocal affect are rare. We investigated audiovisual integration of emotional faces and voices in three groups: schizophrenic patients, non-schizophrenic psychosis patients and mentally healthy controls, all diagnosed by means of the Schedules of Clinical Assessment in Neuropsychiatry (SCAN 2.1). We found diminished crossmodal influence of emotional faces on emotional voice categorization in schizophrenics, but not in non-schizophrenia psychosis patients. Results are discussed in the perspective of recent theories on multisensory integration.

Anxiety and mood disorders in narcolepsy: a case–control study

INTRODUCTION Narcolepsy is a primary sleeping disorder with excessive daytime sleepiness and cataplexy as core symptoms. There is increasing interest in the psychiatric phenotype of narcolepsy. Although many authors suggest an overrepresentation of mood disorders, few systematic studies have been performed and conflicting results have been reported. Anxiety disorders in narcolepsy have only received little attention. METHODS We performed a case-control study in 60 narcolepsy patients and 120 age- and sex-matched controls from a previous population study. The Schedules for Clinical Assessment in Neuropsychiatry were used to assess symptoms and diagnostic classifications of mood and anxiety disorders. RESULTS Symptoms of mood disorders were reported by about one third of patients. However, the prevalence of formal mood disorder diagnoses - including major depression - was not increased. In contrast, more than half of the narcolepsy patients had anxiety or panic attacks. Thirty-five percent of the patients could be diagnosed with anxiety disorder (odds ratio=15.6), with social phobia being the most important diagnosis. There was no influence of age, sex, duration of illness or medication use on the prevalence of mood or anxiety symptoms and disorders. DISCUSSION Anxiety disorders, especially panic attacks and social phobias, often affect patients with narcolepsy. Although symptoms of mood disorders are present in many patients, the prevalence of major depression is not increased. Anxiety and mood symptoms could be secondary complications of the chronic symptoms of narcolepsy. Recent studies have shown that narcolepsy is caused by defective hypocretin signaling. As hypocretin neurotransmission is also involved in stress regulation and addiction, this raises the possibility that mood and anxiety symptoms are primary disease phenomena in narcolepsy.

The relationship between dimensional personality models and quality of life in psychiatric outpatients.

This study examines the relationship between personality and quality of life (QOL) in psychiatric outpatients (N=495). Personality was conceptualized using two-dimensional models, respectively, the five-factor model (FFM) and Cloningers seven-factor model. The WHOQOL-100 was used for assessing QOL. Neuroticism and Harm Avoidance had negative correlations with QOL, whereas Extraversion, Conscientiousness and Self-Directedness correlated positively with QOL. A considerable part of the QOL variance was explained by personality; Cloningers character factors were superior to the FFM domains. Although not fully comparable, in general our findings are in accordance with earlier studies. Therefore, paying attention to personality and temperament is recommended in future diagnostic procedures, treatment policies, and program evaluations.

Quality of life and psychopathology: investigations into their relationship.

Objective: Quality of life (QOL) has become a topic of growing interest in medical and psychiatric practice in general, and in research in particular. Although the body of knowledge about the complex relationship between QOL and psychiatric disorders is growing, understanding this relationship still remains difficult. Therefore, the aim of the present study was to get more and new insights into this relationship. It was hypothesized that QOL would be negatively related to the presence as well as the severity of psychopathology. Method: A random sample of Dutch adult psychiatric outpatients (n=410) completed the World Health Organization Quality of Life assessment instrument, abbreviated version (WHOQOL-Bref). In addition, DSM-IV axis I and II diagnoses were obtained. Comparisons were made between scores of the psychiatric outpatients, diagnostic subgroups within this population, and the scores of a general population. Results: Compared with the general population, psychiatric outpatients scored significantly worse on all aspects of QOL. Within the group of outpatients, participants with DSM-IV diagnoses had worse scores than those without. Participants with comorbidity had the worst QOL. Conclusions: It is concluded that QOL scores are negatively related to both the presence and the severity of psychopathology, and that the presence of a personality disorder plays a role in subjectively experienced QOL.

Perceiving emotions from bodily expressions and multisensory integration of emotion cues in schizophrenia

Most studies investigating emotion recognition in schizophrenia have focused on facial expressions and neglected bodily and vocal expressions. Furthermore, little is known about affective multisensory integration in schizophrenia. In the first experiment, the authors investigated recognition of static, face-blurred, whole-body expressions (instrumental, angry, fearful, and sad) with a two-alternative, forced-choice, simultaneous matching task in a sample of schizophrenia patients, nonschizophrenic psychotic patients, and matched controls. In the second experiment, dynamic, face-blurred, whole-body expressions (fearful and happy) were presented simultaneously with either congruent or incongruent human or animal vocalizations to schizophrenia patients and controls. Participants were instructed to categorize the emotion expressed by the body and to ignore the auditory information. The results of Experiment 1 show an emotion recognition impairment in the schizophrenia group and to a lesser extent in the nonschizophrenic psychosis group, and this for all four expressions. The findings of Experiment 2 show that schizophrenia patients are more influenced by the auditory information than controls, but only when the auditory information consists of human vocalizations. This shows that schizophrenia patients are impaired in recognizing whole-body expressions, and they show abnormal affective multisensory integration of bimodal stimuli originating from the same source.

Modality-specific attention and multisensory integration of emotions in schizophrenia: Reduced regulatory effects

BACKGROUND Deficits in emotion perception are a well-established phenomenon in schizophrenic patients and studies have typically used unimodal emotion tasks, presenting either emotional faces or emotional vocalizations. We introduced bimodal emotion conditions in two previous studies in order to study the process of multisensory integration of visible and audible emotion cues. We now build on our earlier work and address the regulatory effects of selective attention mechanisms on the ability to integrate emotion cues stemming from multisensory channels. METHODS We added a neutral secondary distractor condition to the original bimodal paradigm in order to investigate modality-specific selective attention mechanisms. We compared schizophrenic patients (n=50) to non-schizophrenic psychotic patients (n=46), as well as to healthy controls (n=50). A trained psychiatrist used the Schedules of Clinical Assessment in Neuropsychiatry (SCAN 2.1) to diagnose the patients. RESULTS As expected, in healthy controls, and to a lesser extent in non-schizophrenic psychotic patients, modality-specific attention attenuated multisensory integration of emotional faces and vocalizations. Conversely, in schizophrenic patients, auditory and visual distractor conditions yielded unaffected and even exaggerated multisensory integration. CONCLUSIONS These results suggest that schizophrenics, as compared to healthy controls and non-schizophrenic psychotic patients, have modality-specific attention deficits when attempting to integrate information regarding emotions that stem from multichannel sources. Various explanations for our findings, as well as their possible consequences, are discussed.