Johansson A, Nordin S, Heiden M, Sandström M. (2010). Symptoms, personality traits, and stress in people with mobile phone-related symptoms and electromagnetic hypersensitivity. J Psychosom Res. 68(1):37-45.
Some people attribute their symptoms (such as skin symptoms, dizziness, fatigue, headache, sleep disorders, and cognitive disturbances) to electromagnetic field (EMF) either from electrical equipment in general (perceived electromagnetic hypersensitivity, EHS) or from specific sources, mainly from mobile phones (MP). Based on research and clinical observations, it is suggested that these 2 groups may differ with respect to their symptoms, and also with respect to attitudes and behaviours in relation to exposure sources.
The objective of this study was two-fold: 1) to compare individuals with EHS and individuals with mobile phone associated symptoms in terms of prevalence of symptoms and to compare both groups with a population-based sample; 2) to compare the 2 groups in terms of levels of anxiety, depression, somatization, exhaustion and stress, and to compare both groups with a population sample and with a healthy control group.
Subjects with EMF-associated symptoms were invited to participate through newspaper advertisements. Those who responded to the advertisement were sent a set of questionnaires. For each person with EMF-associated symptoms who completed the questionnaire, two sex- and age-matched reference participants were selected from the Swedish population register. The same questionnaires were sent to the reference participants. The participants with EMF-attributed symptoms were divided into the mobile phone group and the EHS group based on the EMF sources that reportedly provoked their symptoms. Of 160 individuals with EMF-related symptoms who responded to the advertisement, 117 (73%) completed the study. This proportion was 45% (106 of 234) for the reference participants. For comparison with the mobile phone and EHS groups (the “case groups”), both the entire population-based sample and a control group - a sub-sample (n=63) from which reference participants reporting EMF-associated symptoms were excluded - were used. These 2 groups were collectively referred to as the “reference group”.
The mobile phone group, EHS group and the reference group differed in terms of age, gender, proportion of smokers, and employment status. The number of symptoms (EMF-related and EMF-unrelated) reported by the EHS group was significantly greater than that reported by the mobile phone group, and in both case groups it was greater than in the reference group. The EHS group experienced EMF-related symptoms for a longer time than the mobile phone group and the population-based group. The mobile phone group predominantly reported somatosensory symptoms localized to the head (warmth behind, around or on the ear), while the EHS group reported more symptoms of neurasthenic nature (fatigue, concentration difficulties, dizziness). The case groups scored higher than the reference groups on most aspects of personality traits and stress. In a direct comparison between the mobile phone and the EHS groups, they differ significantly only for somatization and listlessness.
Interpretation and Conclusion
The findings of this study support the subdivision of individuals with EMF-related symptoms according to the sources of EMF to which the symptoms are attributed. The observed differences may be important for prognosis and should be considered in the choice of treatment.