"Involutive melancholy" is discussed as it is presented in the literature. It is hypothesised that the controversy regarding this clinical entity arises out of the existence of different pictures and from the incomplete diagnostic examination. On the basis of clinical cases, it is observed that in certain patients, late onset depression represents the start of a deterioration process before it is clinically evident. The Rorschach test is an effective investigation tool in differential diagnosis in the early phase, through signs of a diminution of control and efficiency from the two-fold affective and rational viewpoint.