The prevalence of myasthenia gravis (MG) in the counties of Hordaland and Sogn & Fjordane on January 1, 1984 was 9.6 per 100,000 inhabitants. Other autoimmune diseases were found in 11 out of 48 MG patients. The occurrence of autoimmune thyroiditis (5 patients, 10.4%) and systemic lupus erythematosus (4 patients, 8.3%) in the MG patients was clearly higher than that reported in the general population. Rheumatoid arthritis was found in 2 patients (4.2%). The autoimmune diseases were mainly recorded among the nonthymectomized MG patients. In addition to those with definite diseases of autoimmune nature, 3 other MG patients had thyroid antibodies and 1 had antinuclear factor without clinical evidence of autoimmune disease. Seven MG patients (14.6%) had unspecific arthralgia during active periods of MG. Two MG patients had ankylosing spondylitis.

Health and mental and physical capability determine the overall incidence of disability pension, but marginal fluctuations over time seem to be related to environmental conditions in the labour market, especially the unemployment rate. The observed disability pension incidence pattern in the two unemployment cycles of the study period indicates mainly that people with impaired health are forced out of the labour market in times of increasing unemployment rather than pointing towards a negative effect of unemployment on health. Our findings indicate that there is a need to strengthen the vocational rehabilitation system in Iceland as well as the support system for employment and social participation.

Plasma exchange (PE) was performed in 6 patients with myasthenia gravis (MG). Acetylcholine receptor (AChR) antibodies and other MG-correlated antibodies were quantified each day before, during and after PE. The antibody concentrations decreased during PE with a consisting increase between two exchanges. Repeated PE induced a transient decline in the AChR antibody concentration. The clinical improvement was maximal during the week after PE and correlated in time with increasing concentrations of AChR antibodies.

The prevalence of lifetime psychiatric disorders was investigated among all known systemic lupus erythematosus (SLE) patients in Iceland. The participation rate was 81%. Over 49% of the subjects received a lifetime psychiatric diagnosis. The number of diagnoses per person was 2.3. The most common disorder among those with a disorder was phobia (56%), followed by generalized anxiety (12%). Agoraphobia with and without panic, simple, social phobia, and alcohol abuse were found to be more common among the SLE patients in comparison with a population sample (p < 0.02; p < 0.0001; p < 0.001; p < 0.0001; p < 0.05, respectively). A possible explanation of the high rate of phobia may be related to the nature of clinical disfiguring facial skin rashes which may lead to social withdrawal.

The most likely explanation for the changes we observe is alteration in social conditions leading to a lower threshold for seeking disability pension for mental disorders.