This first part of a multiphase longitudinal study looks at life events implicated in manic depression among an American working class, bipolar sample. Three turning points are identified. a) Stressful life events occurred that resulted in loss of significant social roles. b) Attempts to regain or replace the roles or otherwise “fight back” proved ineffective. c) Retreat via depression, and rebellion via mania, ensued. These turning points were well verified for 75 per cent of the subjects prior to first onset, and for 56 per cent prior to most recent onset. Special methodological issues are raised, and the need for a biopsychosocial etiology of manic depression is suggested.