title: The impact of Herpes simplex virus type 1 on cognitive impairments in young, healthy individuals - A historical prospective study.
abstract: Herpes simplex virus (HSV) is a highly prevalent neurotropic virus. Although on the whole, chronic, latent or persistent infection is considered to be relatively benign, HSV infections can cause cognitive impairment during and after acute encephalitis. Some studies have documented cognitive impairment in exposed persons that is untraceable to encephalitis. Most studies have focused on these impairments in the mentally ill, mostly among individuals with schizophrenia, and only recently have studies begun to examine the impact of HSV infection on the cognition of healthy individuals. Subjects were a representative, random sample of 612 soldiers before active duty in the Israeli military (Israeli defense force - IDF), 62.2% HSV positive (n=381) and 38.8% HSV negative (n=231). Cognitive functioning and language abilities were compared between these groups, controlling for years of education, immigration status, and gender. Compared to soldiers who were sero-negative, soldiers who were sero-positive for HSV had significantly lower IQ scores (IQ=97.96, SD=15.19 vs IQ=103.23, SD=14.23; p≤0.001, effect size (ES)=0.2), and significantly lower Hebrew language scores (ES=0.1, p≤0.01). The results remained significant after removing subjects with mild depression, anxiety or personality disorders. Although we could not control for socio-economic status directly, our findings indicate that infection with HSV-1 is associated with reduced cognitive functioning in healthy individuals. This finding adds to the growing number of studies in the schizophrenia literature and indicates that many research findings seemingly characteristic of schizophrenia are related to the association between HSV exposure and cognitive functioning in general, and are not illness specific.
authors.affiliation: IDF Medical Corps, Mental Health Center, Israel; USC - School of Social Work, C.I.R. Los Angeles, CA, USA.
authors.forename: Eyal
authors.initials: E
authors.lastname: Fruchter
authors.affiliation: Department of Psychiatry, Sheba Medical Center, Tel-Hashomer, Ramat Gan, Israel.
authors.forename: Shira
authors.initials: S
authors.lastname: Goldberg
authors.affiliation: Department of Psychiatry, Sheba Medical Center, Tel-Hashomer, Ramat Gan, Israel.
authors.forename: Daphna
authors.initials: D
authors.lastname: Fenchel
authors.affiliation: Ministry of Health, Jerusalem, Israel; Faculty of Health Sciences, Ben Gurion University of the Negev, Beer Sheva, Israel.
authors.forename: Itamar
authors.initials: I
authors.lastname: Grotto
authors.affiliation: IDF Medical Corps, Mental Health Center, Israel.
authors.forename: Keren
authors.initials: K
authors.lastname: Ginat
authors.affiliation: IDF Medical Corps, Mental Health Center, Israel; Department of Psychiatry, Sheba Medical Center, Tel-Hashomer, Ramat Gan, Israel; Sackler School of Medicine, Tel Aviv University, Ramat Aviv, Israel. Electronic address: mweiser@netvision.net.il.
authors.forename: Mark
authors.initials: M
authors.lastname: Weiser
mesh_terms: D000375:Aging; D000704:Analysis of Variance; D003072:Cognition Disorders / Q000209:etiology* / Q000821:virology; D005260:Female; D006561:Herpes Simplex / Q000150:complications*; D018259:Herpesvirus 1, Human / Q000472:pathogenicity; D006801:Humans; D007360:Intelligence; D008297:Male; D008889:Military Personnel; D009483:Neuropsychological Tests; D011446:Prospective Studies; D011569:Psychiatric Status Rating Scales; D055815:Young Adult
keywords: Cognition; Herpes simplex virus (HSV); Schizophrenia