The aetiology of schizophrenia: what have the Swedish Medical Registers taught us?

Abstract

Although some difficulties exist in analysing the interplay between each of these factors, the Swedish population registers have added considerably to our understanding of each of the presented individual aetiological themes. The ability to study the whole population over several decades has been particularly useful in determining the timing of exposures.

Artistic creativity and risk for schizophrenia, bipolar disorder and unipolar depression: a Swedish population-based case–control study and sib-pair analysis

“…One of the primary strengths of Swedish population-based studies is the almost total population coverage, with minimal selection bias. 12 If the findings had resulted from any biases inherent to the study design, we would have likely seen associations with the negative exposure (law) and the negative outcome (diabetes), so the absence of any such associations is reassuring.…”

Early Life Bereavement and Schizophrenia

“…2,3 It has been increasingly recognized that genetic predisposition and early environmental exposures interact to shape brain development and function, which may possibly lead to psychiatric disorders including schizophrenia. 4–6 A recent review 7 based on 61 studies using Swedish national registry data summarizes that schizophrenia has a multifactorial etiological bases with factors surrounding pregnancy, parental age, low socioeconomic status, substance misuse, and poor cognitive performance besides population genetics to be associated with an increased risk of later schizophrenia.…”

Conditions Associated with Essential Tremor in Veterans: A Potential Role for Chronic Stress

“…Because PTSD has been associated with obsessive–compulsive disorder (OCD) 6 , 7 and bipolar disorder, 8 , 9 and stress with schizophrenia, 10 we examined these. ET veterans did not have OCD more often than non-ET cases at ages 21–35 or 81–95, but did at ages in between, with OR above 2.4.…”

“…OCD may commence 10 years after a traumatic life event, 6 , 7 thus the doubled rate of OCD among ET veterans between age 36 and 80 is consistent with combat experiences at ages 21–35. The greater rate of schizophrenia can be related to higher rates in tremor cases of risk factors: cannabis use, alcohol abuse, anxiety, bipolar disorder, 10 and TBI. 76 Chronic social stress and social isolation, likely present in stressed ET patients, are also risks for schizophrenia.…”