The results of a genomewide scan for genes conferring susceptibility to anxiety disorders in the Icelandic population are described. The aim of the study was to locate genes that predispose to anxiety by utilizing the extensive genealogical records and the relative homogeneity of the Icelandic population. Participants were recruited in two stages: (1) Initial case-identification by a population screening for anxiety disorders, using the Stamm Screening Questionnaire, was followed by aggregation into extended families, with the help of our genealogy database; and (2) those who fulfilled the diagnostic and family aggregation criteria underwent a more detailed diagnostic workup based on the Composite International Diagnostic Interview. Screening for anxiety in close relatives also identified additional affected members within the families. After genotyping was performed with 976 microsatellite markers, affected-only linkage analysis was done, and allele-sharing LOD scores were calculated using the program Allegro. Linkage analysis of 25 extended families, in each of which at least one affected individual had panic disorder (PD), resulted in a LOD score of 4.18 at D9S271, on chromosome 9q31. The intermarker distance was 4.4 cM on average, whereas it was 1.5 cM in the linked region as additional markers were added to increase the information content. The linkage results may be relevant not only to PD but also to anxiety in general, since our linkage study included patients with other forms of anxiety.

The lifetime prevalence rates are presented for mental disorders in a random sample of people born in Iceland in 1931, interviewed at the age of 55–57 years. The diagnoses are made according to DSM‐III, on the basis of the National Institute of Mental Health's diagnostic Interview Schedule (NIMH‐DIS) used by trained lay interviewers. The most common diagnoses were alcohol abuse and dependence, generalized anxiety disorder, phobic disorders, dysthymic disorder and major depressive episode. Disorders more common in men were antisocial personality, alcohol abuse and alcohol dependence. Disorders more common among women were major depressive episode and generalized anxiety disorder. Alcohol abuse was more prevalent among those living in rural areas, but dependence was more prevalent in the urban area, where panic disorder is also more frequent. Widowed, separated and divorced people had most of the highest prevalences: tobacco‐use disorder, alcohol abuse and dependence, dysthymia and generalized anxiety disorder. Except for a very high rate of alcohol abuse and dependence and a low rate of substance abuse disorders, the prevalence rates are similar to those obtained in North American studies using the NIMH‐DIS as a survey instrument. The DSM‐III criteria for alcohol abuse or dependence may be less applicable to Iceland than to North America, because of differences in what is culturally regarded as acceptable use of alcohol.

In this study, the largest Nordic study of its kind, investigated psychosexual dysfunction among subjects aged 55-57 years. The cohort included 862 subjects of both sexes and all were interviewed using the Diagnostic Interview Schedule (DIS). Results showed that 122 subjects had a lifetime diagnosis of psychosexual dysfunction. The lifetime prevalence of psychosexual dysfunction was 14.4%; of inhibited sexual desire, 9.8%; of inhibited sexual excitement, 3.5%; of inhibited orgasm, 2.1%; and of functional dyspareunia, 1.3%. Of the subjects with psychosexual dysfunction, 73% were women. The frequency was highest in those who had never married. Separated subjects had rates intermediate between the married and the never-married. The majority (76%) of affected subjects had only one dysfunction. However, 57% of them had received another psychiatric diagnosis at some time. Subjects with psychosexual dysfunction were less frequently diagnosed as suffering from alcohol abuse and dependence and social phobia than subjects with no psychosexual dysfunction.

The study was carried out to estimate the prevalence of chronic fatigue syndrome (CFS) in Iceland. No previous prevalence studies known to us have been undertaken in Iceland or in Scandinavia. A 95-item custom-made questionnaire was sent to 4000 randomly selected people. The response rate was 63%. The questionnaire was constructed to include questions on all the items found in the four most common criteria for diagnosing CFS; the criteria being Australian, British and American. Results show very different prevalences according to the criteria used. The prevalence ranged from 0 to 4.9%, with the most established criteria yielding a prevalence of 1.4%. Re-test validity of the questionnaire was good, the following results are based on the selection criteria by Fukuda et al. (Fukuda K, Straus SE, Hickie I, Sharpe MC, Dobbins JG, Komaroff A, et al. The chronic fatigue syndrome: a comprehensive approach to its definition and study. Ann Int Med 1994;121:953-9). Women were in a majority (78%); their mean age was 44, they were fully employed and worked long hours. They believed that the onset of their symptoms was stress related. The type of work was unskilled in the majority of cases. A significant proportion of the males felt a constant buzzing in their ears (P < 0.05). Food suppliants were used daily by significantly more women than men (P < 0.01). Men had more frequently phobic symptoms (P < 0.001) than did women. Differences were found in the prevalence of phobia and panic (P < 0.001) between women in the CFS group compared to healthy ones. A positive correlation was found in the prevalence of phobia between women in the CFS group and those with Iceland Disease.

The lifetime prevalence of anxiety disorders was estimated in a study of the prevalence of mental disorders in Iceland. The survey instrument was an Icelandic translation of the US National Institute of Mental Health Diagnostic Interview Schedule. The cohort consisted of one half of those born in the year 1931. The participation rate was 79.3%. The overall prevalence of anxiety disorders was 44%, with phobia effecting 18%. The most common anxiety disorder was generalized anxiety, which had a prevalence of 22% and was more common among women. Simple phobia was the most common of the phobic disorders (8.8%), followed by agoraphobia without panic (3.8%), and social phobia (3.5%). The female-male ratio for anxiety disorders was 2:1. Of those with simple phobia, the most common items were a fear of heights (41%); claustrophobia (34%); being on public transportation (31%); the fear of being in crowds and speaking in front of others (28%); of being alone (24%); of insects (22%); of bad weather (21%); and of being in water (aquaphobia) (20%). In addition, 17% of the respondents listed phobias not cited in the DSM-III, and of those with the most common phobic disorder, only 9% had consulted a physician because of this condition. Post-traumatic stress disorder was found to affect women exclusively. Comorbidity shows a mean of at least 3 additional diagnoses.