Relation of schizophrenia prevalence to latitude, climate, fish consumption, infant mortality, and skin color: a role for prenatal vitamin d deficiency and infections?
Previous surveys found a large (>10-fold) variation in schizophrenia prevalence at different geographic sites and a tendency for prevalence to increase with latitude. We conducted meta-analyses of prevalence studies to investigate whether these findings pointed to underlying etiologic factors in schizophrenia or were the result of methodological artifacts or the confounding of sites’ latitude with level of healthcare at those sites. We found that these patterns were still present after controlling for an index of healthcare—infant mortality—and focusing on 49 studies that used similar diagnostic and ascertainment methods. The tendencies for schizophrenia prevalence to increase with both latitude and colder climate were still large and significant and present on several continents. The increase in prevalence with latitude was greater for groups with low fish consumption, darker skin, and higher infant mortality—consistent with a role of prenatal vitamin D deficiency in schizophrenia. Previous research indicates that poor prenatal healthcare and nutrition increase risk for schizophrenia within the same region. These adverse conditions are more prevalent in developing countries concentrated near the equator, but schizophrenia prevalence is lowest at sites near the equator. This suggests that schizophrenia-producing environmental factors associated with higher latitude may be so powerful they overwhelm protective effects of better healthcare in industrialized countries. The observed patterns of correlations of risk factors with prevalence are consistent with an etiologic role for prenatal vitamin D deficiency and exposure to certain infectious diseases. Research to elucidate environmental factors that underlie variations in schizophrenia prevalence deserves high priority.
Computerized EEG and evoked auditory potential investigations demonstrated that the patterns of a group of children at high risk for schizophrenia (children of schizophrenic parents) had statistically significant differences when compared with those of a matched control group of children. High-risk children were characterized by the presence of high-frequency beta activity, fewer fast alpha waves, and more very slow low-voltage delta activity in computerized EEG as well as by shorter latencies in auditory evoked potential. These neurophysiological characteristics of high-risk children showed striking similarities to computerized EEG and evoked potential findings in psychotic children and schizophrenic adults, suggesting that this pattern may be the neurophysiological measurement of schizophrenia. These findings support some of the most recent biochemical hypotheses in schizophrenia and, if confirmed by further work, suggest new means in the preventive treatment of this illness.
Music therapy as an addition to standard care helps people with schizophrenia to improve their global state and may also improve mental state and functioning if a sufficient number of music therapy sessions are provided. Further research should address the dose-effect relationship and the long-term effects of music therapy.
Music's Effect on the Human Body →
Music therapy and schizophrenia.
Social Brain Hypothesis and Schizophrenia
Thus, individuals with this disease find themselves seriously disadvantaged in the social arena, unable to correctly read and respond to social signals, and vulnerable to the stresses of their complex social environments. This state of “disembodiment” and interpersonal alienation is the core phenomenon of schizophrenia and the root cause of intolerable suffering in the lives of those affected.
Hyperreflexivity and Cultural Circumstances
Hyperreflexivity, understood as intensified self-consciousness in which subjects disengage from normal forms of involvement with nature and society, often considering themselves as objects of focal awareness, is proposed here as a condition of mental disorders, without which they would not exist. This thesis is argued from a dual perspective: clinical and historical. In the clinical perspective, it is shown that hyperreflexivity is not merely concomitant with mental disorders, but indeed has causal priority over them. Empirical evidence of a correlational, experimental and therapeutic nature, or deriving from cultural change, supports this claim of causal priority. In the historical perspective, it is shown that hyperreflexivity depends on certain historical-cultural circumstances that have prevailed since the Renaissance. These circumstances have to do with the emergence of the modern subject, displaced, autonomous and condemned to a hapless ‘interior journey’. This means that mental disorders as such would not have existed prior to that era. Nor in the wake of the Renaissance would mental disorders automatically come into being, depending as they do on a reflexive, institutional clinical context, which would not emerge until practically the nineteenth century, but which would extend swiftly from then on.
Schizophrenia and Memory
OBJECTIVE: Memory impairment is well documented in schizophrenia. Less is known, however, about the exact magnitude, pattern, and extent of the impairment. The effect of potential moderator variables, such as medication status and duration of illness, is also unclear. In this article, the authors presented meta-analyses of the published literature on recall and recognition memory performance between patients with schizophrenia and normal comparison subjects. METHOD: Meta-analyses were conducted on 70 studies that reported measures of long-term memory (free recall, cued recall, and recognition of verbal and nonverbal material) and short-term memory (digit span). Tests of categorical models were used in analyses of potential moderators (clinical variables and study characteristics). RESULTS: The findings revealed a significant and stable association between schizophrenia and memory impairment. The composite effect size for recall performance was large. Recognition showed less, but still significant, impairment. The magnitude of memory impairment was not affected by age, medication, duration of illness, patient status, severity of psychopathology, or positive symptoms. Negative symptoms showed a small but significant relation with memory impairment. CONCLUSIONS: This meta-analysis documented significant memory impairment in schizophrenia. The impairment was stable, wide ranging, and not substantially affected by potential moderating factors such as severity of psychopathology and duration of illness.
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