Maternal Flu and Risk of Bipolar Disorder
Several past studies have investigated a possible link between infections during pregnancy and psychiatric illness in the offspring. These studies may be biased, however, by poor recall or by a clinical,
as opposed to serological, diagnosis of infection in the mother. A recent study attempted to overcome this bias by measuring influenza antibodies—a more precise manner of identifying influenza
exposure—drawn from the mothers of bipolar offspring.
Researchers used data from the Child Health and Development Study birth cohort, a representative sample of all people born to women who received obstetric care in a Northern California HMO between 1959 and 1966. They obtained frozen serum samples from the mothers of 85 individuals with bipolar disorder and measured influenza antibodies, comparing them to matched samples from 170 control peers. The bipolar individuals included 36 with psychotic features and 49 without.
The mothers of 23 of the bipolar subjects had influenza antibodies in their blood (27%). Overall, no increased risk of bipolar disorder was found among the offspring of women exposed to the flu during pregnancy (odds ratio 1.26, 95% CI=0.625-2.44, p=0.49) when compared to matched peers.
However, when the bipolar individuals were separated into those with psychotic features and those
without, the picture changed. Maternal influenza exposure was related to a five-fold greater risk of bipolar disorder with psychotic features (odds ratio 4.87, 95% CI=1.18-20.06, p=0.028).
Thirty-nine percent of the mothers of adults with bipolar disorder with psychotic features had influenza antibodies in their blood, versus only 18.4% of the moms of the bipolar individuals without psychotic features (Canetta SE et al, Am J Psychiatry 2014;171(5):557—563).
TCPR’s Take: This study lends additional support to the idea that maternal infection increases the risk for psychiatric illness in the offspring. While the current study found no increased risk of bipolar disorder, it did identify a greater risk of bipolar disorder with psychotic features, supporting earlier
observations that maternal influenza may contribute to the development of schizophrenia.
The authors argue that maternal influenza may affect brain development to increase the risk of psychosis, suggesting novel neurobiological approaches for research into the diagnosis and treatment of psychotic disorders.
The Media’s Role in Suicide Clusters
Does newspaper coverage of suicide promote copycat suicides? A recent retrospective study examined this question by comparing suicide clusters among teens to isolated suicides, and how local newspapers covered these events.
Researchers looked at 48 suicide clusters (three or more suicides occurring in the same community within a span of 23 weeks) among teens ages 13 to 20, all of which occurred in the US between 1988 and 1996. They collected newspaper reports published between the first and the second suicide of the cluster, to determine whether any aspects of the newspaper report (headline, frontpage placement, graphic descriptions, etc) were more highly associated with the onset of a “cluster” than others.
For each cluster, researchers identified two control suicides, in other communities in the same state, which were not part of a suicide cluster. They evaluated newspaper reports of these suicides as well.
Researchers found that significantly more newspaper articles were published between the first and second suicides in suicide clusters than during the same period of time after an isolated suicide (7.42 vs 5.14, p<0.0001).
Using a statistical process assessing both the number of articles and specific features of those accounts, researchers found that the articles published in communities where clusters developed were significantly more likely to feature the name of the victim and the method used, and to feature the word “suicide” in the headline. They were also more likely to mention the name of the victim’s school and to be accompanied by a “sad” photograph (Gould M et al, Lancet Psychiatry 2014;online ahead of print).
TCPR’s Take: Knowledge about a suicide—particularly when detailed and explicit—may increase the risk of subsequent suicides in teenagers. The authors of this study hypothesize that newspaper reports might “normalize” suicide or may “prime” other individuals to consider suicide.
However, because the data were collected before the age of social media, conclusions cannot be drawn about online accounts of suicide. The ubiquity of social media may enable the rapid dissemination of suicide stories and increase the risk of subsequent suicides, but it may also facilitate productive dialogue about the unfortunate nature of such events and provide a measure of safety.