Is there a loss of efficacy of lithium in patients treated for over 20 years?

Diminishing efficacy of lithium prophylaxis in initially well-responding pa tients during long-term treatment as well as after interruption of prophyla xis has been described repeatedly in the past. For the present analysis, 22 patients with bipolar and unipolar affective disorder continuously treated and documented in a specialized lithium outpatient clinic over at least 20 years were included, The cumulative affective morbidity of the first 10 ye ars versus the second 10 years of prophylactic treatment was subjected to s tatistical and single-case (life chart method) analysis. There was no stati stical evidence for diminishing efficacy of lithium prophylaxis. The increa se in the Morbidity Index in single patients in a case-related individual a pproach could be revealed as not necessarily due to an alleged loss of effi cacy of lithium, but more likely to be due to the atypical features in the psychopathology and course of illness. Copyright (C) 2000 S. Karger AG, Bas el.