DEPRESSION AND MULTIPLE-SCLEROSIS

The objectives of the present study were (1) to ascertain the lifetime risk of a depression in a representative group of multiple sclerosis (MS) patients, (2) to assess the morbidity risks for depression among first-degree relatives of these MS patients, and (3) to compare these familial risks for first-degree relatives of MS patients with those fo r first-degree relatives of a primary depression population, i.e., dep ression but no MS. We psychiatrically evaluated 221 MS patients (index cases) using a structured clinical interview for the DSM-III-P and ca lculated the rate and lifetime risk of depression for these index case s using the product limit estimate of survival function. We obtained p sychiatric histories for all first-degree relatives of index cases, an d we calculated morbidity risks for depression for these relatives usi ng the maximum likelihood approach and compared the risks using the li kelihood ratio tests. Index cases had a 50.3% lifetime risk of a depre ssion. Morbidity risks for depression among first-degree relatives of index cases were decidedly lower when compared with morbidity risks am ong first-degree relatives of the reference population. Although there appears to be a very high rate of depression among MS patients, the d ata for their first-degree relatives do not support a clear genetic ba sis for this depression, or at least the same genetic basis that proba bly operates within families when depression occurs in the absence of MS.