Journal Digest

Symptoms of depression, attention-deficit/hyperactivity disorder (ADHD), social phobia, and hostility in junior high school students significantly predicted the risk of developing so-called “Internet addiction” in the next two years, according to a study of more than 2,000 adolescents in Taiwan.

Whether Internet addiction should become a formal psychiatric diagnosis remains controversial.

The authors of the study used a set of previously tested criteria (Chen Internet Addiction Scale) based on symptoms of preoccupation, uncontrolled impulses, usage more than intended, tolerance, withdrawal, impaired control, excessive time and effort spent on the Internet, and impaired decision making. The study participants—seventh graders from 10 schools—were assessed using standardized questionnaires at baseline and six, 12, and 24 months later.

In boys, ADHD (measured by the ADHD Self-Rated Scale) and hostility (measured by the Buss-Durkee Hostility Inventory—Chinese Version—Short Form) at baseline had a statistically significant association with the risk of developing Internet addiction during the two-year follow-up. In girls, meeting the criteria for depression (measured by the Center for Epidemiological Studies Depression Scale), ADHD, social phobia (measured by the Brief Version of the Fear of Negative Evaluation Scale), and hostility at baseline significantly predicted the emergence of Internet addiction.

A new case-control study casts doubt on a proposed neuroimmunological etiology for a subtype of pediatric Tourette syndrome (TS) and obsessive-compulsive disorder (OCD) known as pediatric autoimmune neuropsychiatric disorders associated with streptococcal infection (PANDAS). The authors identified a cohort of 129 cases, aged 2 to 25, with an OCD, TS, or other tic disorder diagnosis in a primary care database in the United Kingdom and a control cohort without these diagnoses from persons matched for age, gender, and type of practice.

The case cohort did not have a statistically significant increase in the frequency of possible streptococcal infection in the two years before their first diagnosis of OCD, TS, or other tic disorder, compared with the matched control cohort. In subgroup analysis, OCD patients had a statistically significantly elevated likelihood of having had possible streptococcal infections without antibiotic treatment before the OCD diagnosis (odds ratio [OR] 2.50, 95 percent confidence interval [CI] 1.18-5.69).

Previous observational studies have suggested a connection between streptococcus infection and subsequent appearance of OCD/tics in a small proportion of children with the neuropsychiatric symptoms. An accompanying editorial to the study pointed out that PANDAS may be difficult to tease out clinically from the majority of “ordinary” OCD and other neuropsychiatric disorders in children. The editorial also concluded that for most TS and OCD patients, streptococcal infection “does not seem to be an important etiological factor and therefore not an appropriate target for assessment or therapy.”

The use of selective serotonin-reuptake inhibitors (SSRIs) by pregnant women was associated with a small but statistically significant increase in the risk of adverse birth outcomes for their infants in a large retrospective study. The subjects included in this study were 57,001 pregnant women who received care and gave birth at the Aarhus University Hospital in Denmark between 1989 and 2006. Among these women, 329 received SSRIs during pregnancy, 2,902 had a psychiatric illness but no exposure to SSRIs during pregnancy, and 51,770 had no history of psychiatric illness.

After adjusting for confounding factors, women with SSRI exposure during pregnancy showed statistically significantly higher risk of preterm delivery (OR 2.05, 95 percent CI 1.28-3.31), infant admission to the neonatal intensive care unit (OR 2.04, 95 percent CI 1.42-2.94), and a five-minute Apgar score below 8 (OR 6.58, 95 percent CI 3.39-12.74), compared with women who had a history of psychiatric illness but no SSRI exposure. These differences remained significant in the comparison between women with SSRI exposure and women who had neither history of psychiatric illness nor SSRI exposure during pregnancy. The infants' head circumference and birth weight did not differ significantly among the three categories of pregnant women.

The authors did not analyze any effect of the timing of SSRI use during pregnancy on birth outcomes.

Epidemiological data suggest that the likelihood of septal heart defects is increased in children born to mothers who are prescribed SSRIs in early pregnancy. An analysis of medical data was conducted on all children born in Denmark between 1996 and 2003, amounting to nearly half a million, and their mothers' history of filling SSRI prescriptions in the first trimester (defined as within 28 days before and 112 days after the beginning of gestation). The authors found no significant association between the mothers' SSRI prescriptions and the children's risk of all major malformations, except for an elevated risk of septal heart defects (OR 1.99, 95 percent CI 1.13 to 3.53). In subgroup analyses, associations were statistically significant for sertraline (OR 3.25, 95 percent CI 1.21 to 8.75) and citalopram (OR 2.52, 95 percent CI 1.04 to 6.10), but not for fluoxetine (OR 1.34, 95 percent CI 0.33 to 5.41).

The authors emphasized that the absolute effects of maternal SSRI use were small. Only 0.5 percent of the control subjects, or children born to mothers who did not take any SSRI, had septal heart defects, compared with 0.9 percent in children whose mothers were prescribed any SSRI.

Children born to women who smoked tobacco or drank alcohol during pregnancy were more likely to have psychotic symptoms at age 12 compared with their peers born to nonsmoking, nondrinking mothers. The analysis was derived from 6,356 children in the Avon Longitudinal Study of Parents and Children. The study was a large, prospective, longitudinal study, conducted in the United Kingdom, in which more than 14,000 children were followed from birth to examine the effects of genetic and environmental factors on child development. Suspected or definite psychotic symptoms, measured with the Psychosis-Like Symptoms semistructured interview (PLIKSi) at 12 years, were identified in 11.6 percent of the cohort, including 4.7 percent who had definite psychotic symptoms.

Maternal tobacco use during pregnancy was significantly associated with the risk of suspected or definite psychotic symptoms (OR 1.20, 95 percent CI 1.18-1.49). The link appeared to be dose dependent, as the risk increased with the average number of cigarettes smoked per day. The risk of definite psychotic symptoms only did not reach statistical significance. The frequency of maternal alcohol use was low in the cohort, and there was a marginally significant association between suspected or definite psychotic symptoms with only the highest amount of alcohol use. Maternal cannabis use was not significantly associated with psychotic symptoms in children.

A prospective, longitudinal German study revealed that unipolar and bipolar mood disorders may be more common than previously thought in a community-based sample of young people. More than 3,000 adolescents and young adults were followed and assessed for mood episodes using the computer-assisted Munich-Composite International Diagnostic Interview at three time points over a 10-year period. Participants were deemed to have major depressive disorder (MDD) if they had only major depressive episodes but no manic or hypomanic episodes. Similarly, those who had both a depressive and a manic (or hypomanic) episode were considered to have bipolar disorder.

The study participants were 14 to 24 years old at baseline and 21 to 34 years old at the third assessment. The authors used statistical methods to calculate the cumulative incidence rates to estimate the risk of developing mood episodes over time.

By age 33, the cumulative incidence was 2.9 percent for developing at least one manic episode, 4.0 percent for hypomanic episode, and 29.4 percent for major depressive episode. About 40 percent of the study participants with manic episodes and 68 percent of participants with hypomanic episodes did not develop a major depressive episode during the study window and were considered as having had unipolar mania or hypomania. Of the participants who had major depressive episodes, 88 percent did not have an episode of mania or hypomania and thus were deemed to have unipolar MDD. If the mood episodes were limited to mutually exclusive categories, the cumulative incidence by the age of 33 was estimated at 4.0 percent for bipolar disorder and 26.0 percent for MDD.

Beesdo K, Höfler M, Leibenluft E, et al: Mood Episodes and Mood Disorders: Patterns of Incidence and Conversion in the First Three Decades of Life. Bipolar Disord. 2009;11:637-619