Comparative experimental psychological investigation of continuous schizophrenia and schizoid psychopathy was performed in 60 and 35 patients, respectively aged 16 to 30. Clinical diagnosis was confirmed in catamnestic follow-up. A set of 11 psychological techniques was employed. Differential diagnostic indices were derived from the study of psychic processes in both diseases. Diagnostic significance and informative values were assessed for individual techniques with special reference to their relevance to differential diagnosis of schizophrenia and schizoid psychopathy.