Schizotypal Disorder Resources

MedWire News: The risk for developing schizotypal traits inadulthood appears to be influenced by several early life factors,including low birth weight and family socioeconomic status, but in ahighly gender-specific manner, suggest study results.

Sincesimilar factors have been previously linked to schizophrenia, studyco-author Jari Lahti (University of Helsinki, Finland) and colleaguessay the findings add further weight to developmental and genetictheories of the schizophrenia spectrum.

Schizotypy consists ofpositive and negative schizotypal traits, which closely resemblesymptoms characterizing schizophrenia, Lahti et al explain in the British Journal of Psychiatry.

Notinga lack of studies focussing on risk for schizotypy alone, theresearchers examined individuals enrolled on the Northern Finland 1966Birth Cohort Study (n=4976) who completed a questionnaire on positiveand negative schizotypal traits at the age of 31 years in 1997.

Theyfound that in women, but not men, small placental weight, low birthweight, and small head circumference at the age of 12 months predictedmore pronounced positive schizotypal traits.

For every 100-gincrease in placental weight, 1-kg increase in birth weight, and 1-cmincrease in head circumference at 12 months, the positive symptomsdecreased by 0.04, 0.09, and 0.04 standard deviations, respectively.

Inaddition, later birth order predicted augmented positive traits, andwinter or autumn birth predicted negative traits in women but not men.

Conversely,men, but not women, whose mothers smoked during pregnancy showed anelevated physical anhedonia at 31 years. Also in men, positive andnegative schizotypal traits were more pronounced if the motherconsidered the pregnancy undesired, or desired it later.

In bothwomen and men, negative schizotypal traits were more pronounced in theoffspring of farmers, and positive schizotypal traits were morecharacteristic if the childhood family socioeconomic status was low.

Looking for a possible explanation for their findings Lahti et alnote that “suboptimal early-life environment may induce changes infetal physiology and set the stage for less optimal life-coursedevelopment.”

They add that “different previous studies haveshown clear differences in the epidemiology and course of schizophreniabetween women and men; hypothesized to result, in part, fromdifferences in the growth hormone–insulin-like growth factor axis.”

MedWire(www.medwire-news.md) is an independent clinical news service providedby Current Medicine Group, a part of Springer Science+Business Media. ©Current Medicine Group Ltd; 2009