Family History Of Psychotic Disorder Research Articles

Transition to Psychosis: 6-Month follow-up of a Chinese High-Risk Group in Hong Kong

The identification of individuals at high risk of becoming psychotic within the near future creates opportunities for early intervention before the onset of psychosis. This study sets out to identify a group of symptomatic young people in a Chinese population with the high likelihood of transition to psychosis within a follow-up period of 6 months, and to determine the rate of transition to psychosis in this group. Symptomatic individuals with a family history of psychotic disorder, sub-threshold psychotic symptoms or brief transient psychotic symptoms were identified using the operationalized criteria of an 'At Risk Mental State'. The individuals were prospectively assessed monthly on a measure of psychopathology for 6 months. Eighteen out of 62 individuals (29%) made the transition to frank psychosis within a 6 month follow-up period, with the majority occurring within 3 months. In addition, significant differences were found in the intake Positive and Negative Syndrome Scale, Comprehensive Assessment of 'At Risk Mental State' and Global Assessment of Functioning scores between the group that ultimately became psychotic and the group that did not. The period of the highest risk of transition to psychosis was within the 3 months after the study began. Thus, distressed youths in our outpatient clinic, who meet the high-risk criteria should be monitored most closely in the initial 3 months, particularly those individuals with high levels of psychopathology and functional decline.

Risk factors for psychosis in an ultra high-risk group: psychopathology and clinical features

The identification of individuals at high risk of developing a psychotic disorder has long been a goal of clinicians because it is thought that early treatment of this group may prevent onset of the disorder. However, little is known of predictive factors of psychosis, even within a high-risk group. This study followed up 104 young people thought to be at ‘ultra high risk’ for schizophrenia and other psychotic disorders by virtue of having a family history of psychotic disorder combined with some functional decline or the presence of subthreshold or self-limiting psychotic symptoms. All subjects were therefore symptomatic, but not psychotic, at intake. Thirty-six subjects (34.6%) developed frank psychotic symptoms within 12 months. Measures of symptom duration, functioning, disability and psychopathology were made at intake, 6 and 12 months. Poor functioning, long duration of symptoms, high levels of depression and reduced attention were all predictors of psychosis. A combination of family history of psychosis, a recent significant decrease in functioning and recent experience of subthreshold psychotic symptoms was also predictive of psychosis. Combining highly predictive variables yielded a method of psychosis prediction at 12 months with good positive predictive value (80.8%), negative predictive value (81.8%) and specificity (92.6%) and moderate sensitivity (60.0%). Within our symptomatic high-risk group, therefore, it appears possible to identify those individuals who are at particularly high risk of developing a psychotic disorder such as schizophrenia. Given the very high PPV and low false positive rate with this two-step process, it may be justifiable to target these individuals for intensive monitoring of mental state and even low-dose neuroleptic medication or other biological and psychosocial treatments depending on clinical condition. This indicated prevention approach could be further developed and preventive strategies in the psychoses refined.

Early Treatment May Delay Schizophrenia Onset

Early Treatment May Delay Schizophrenia Onset

Psychosis prediction: 12-month follow up of a high-risk (“prodromal”) group

Intervention in the prodromal phase of schizophrenia and related psychoses may result in attenuation, delay or even prevention of the onset of psychosis in some individuals. However, a “prodrome” is difficult to recognise prospectively because of its nonspecific symptoms. This study set out to recruit and follow up subjects at high risk of transition to psychosis with the aim of examining the predictive power for psychosis onset of certain mental state and illness variables. Symptomatic individuals with either a family history of psychotic disorder, schizotypal personality disorder, subthreshold psychotic symptoms or brief transient psychotic symptoms were assessed and followed up monthly for 12 months or until psychosis onset. Twenty of 49 subjects (40.8%) developed a psychotic disorder within 12 months. Some highly significant predictors of psychosis were found: long duration of prodromal symptoms, poor functioning at intake, low-grade psychotic symptoms, depression and disorganization. Combining some predictive variables yielded a strategy for psychosis prediction with good sensitivity (86%), specificity (91%) positive predictive value (80%) and negative predictive value (94%) within 6 months. This study illustrates that it is possible to recruit and follow up individuals at ultra high risk of developing psychosis within a relatively brief follow-up period. Despite low numbers some highly significant predictors of psychosis were found. The findings support the development of more specific preventive strategies targeting the prodromal phase for some individuals at ultra high risk of schizophrenia.

Heritability heightens brain metabolite differences in schizophrenia.

Single-voxel proton magnetic resonance spectroscopy was performed in 64 medicated schizophrenic patients and 51 healthy subjects. Spectra were obtained from a voxel in the left medial temporal lobe by using a 2.0-tesla whole-body magnetic resonance imaging system. Schizophrenic patients showed a lower N-acetylaspartate/ creatine-phosphocreatine ratio than did healthy subjects, and this reduction was greater in 13 patients with a family history of psychotic disorders.

Predictors of response to lithium in patients with psychoses

This study sought to characterize a subset of patients with DSM-III schizophrenia or schizophreniform disorder who respond to lithium. Sixty-six psychotic patients were given a systematic therapeutic trial of lithium alone. Differences in demographic characteristics, symptoms, and family history of psychotic disorders between the responders and nonresponders to lithium were explored. Responders and nonresponders did not differ significantly in age, duration of illness, length of current episode, distribution of RDC and DSM-III diagnoses, or number of positive symptoms. However, the responders to lithium (N = 10) exhibited a paucity of negative symptoms and an absence of familial schizophrenic spectrum disorders. These preliminary results suggest the possibility of pretreatment identification of psychotic patients for whom neuroleptic medication could be avoided by therapeutic intervention with lithium alone.

A case-control study of Alzheimer's disease in China.

We conducted a case-control study to assess possible factors associated with Alzheimer's disease (AD) with 70 clinically diagnosed AD patients and 140 age- and sex-matched nondemented neighborhood controls in China. Factors significantly associated with AD cases were family history of dementia in first-degree relatives, family history of psychotic disorders in first-degree relatives, and left-handedness/ambidexterity. A history of arthritis showed a significantly negative association with AD. Neither a family history for Down's syndrome, history of head trauma, nor other conditions that might support immune or viral hypotheses in AD were significantly associated with AD cases. These data support the role of familial/genetic factors in AD.

Gating of auditory response in schizophrenics and normal controls: Effects of recording site and stimulation interval on the P50 wave

Auditory evoked potentials were recorded using a paired stimulus, conditioning-testing paradigm from 14 schizophrenic patients and 13 normal subjects with no family history of psychotic disorder. Previous studies of the vertex P50 wave using this paradigm have demonstrated a possible sensory gating deficit in schizophrenics, as shown by their failure to diminish the response to a test stimulus presented 500 ms after a conditioning stimulus. Recordings were made at Cz, Fz, C3, T3, C4, and T4, to compare effects at different recording sites with this paradigm. Schizophrenics had significantly poorer sensory gating than normals, with the most significant difference between the groups at Cz. In addition to the 500 ms interval, subjects were also recorded at a conditioning-testing interval of 100 ms. Most schizophrenics showed normal sensory gating at the 100 ms interval, despite their abnormalities at 500 ms. The results indicate that Cz is an optimal recording site for this paradigm, and that gating abnormalities in schizophrenic subjects are limited to specific interstimulus intervals.

Sensory gating in schizophrenics and normal controls: Effects of changing stimulation interval

Auditory evoked potentials were recorded using a paired click, conditioning-testing paradigm in 10 schizophrenics and in 10 normal subjects with no family history of psychotic disorder. The paradigm is used to demonstrate central nervous system gating of responsiveness to auditory stimuli by examining the extent to which the response to the conditioning stimulus diminishes the response to a test stimulus occurring a short time later. Recordings were made at conditioning-testing intervals of 500 msec, 150 msec, and 75 msec to determine subjects' gating of responsiveness to stimuli repeated at various intervals. The schizophrenics had conditioning-testing ratios indicative of poor gating of the auditory P50 wave at the 500-msec and 150-msec intervals, but most patients had good sensory gating at the 75-msec interval. Normal subjects showed good sensory gating at all three intervals. Results suggest that although sensory gating mechanisms responsible for changes in neuronal response at longer intervals are chronically defective in schizophrenics, other gating mechanisms functioning at shorter intervals appear to be intact and function well in most patients. The results may lead to increased specification of the neurobiological basis of sensory abnormalities in schizophrenia.