Psychological studies in bipolar affective disorder and analogue conditions suggest that mania may be the product of an abnormal defence against depression. In this study, currently manic bipolar individuals, currently depressed bipolar individuals, and normal controls were assessed using explicit and implicit measures of attributional style, an emotional Stroop test with euphoria-related and depression-related words and a recall measure of the selfschema. Manic individuals showed a normal self-serving bias on a version of the explicit attributional style questionnaire, attributing positive events more than negative events to self, in contrast to bipolar-depressed individuals who attributed negative events more than positive events to self. However, on an implicit test of attributional style, both manic and bipolar-depressed individuals attributed negative events more than positive events to self. Both bipolar-manic and bipolar-depressed individuals demonstrated slowed colour naming for depression-related but not euphoriarelated words on an emotional Stroop test. Manic individuals, like normal controls, endorsed primarily positive words as true to self on a self referent questionnaire, but like bipolar-depressed individuals, recalled primarily negative words in a surprise recall test afterwards. Findings from the implicit tests therefore indicate a common form of psychological organisation in manic and depressed individuals, whereas the contrasts between the scores on the implicit and explicit measures are in accord with the hypothesis of a manic-defence. Future avenues for research and implications for treatment are discussed