This paper presents the psychiatric aspects of the concept of basic symptoms (BS), especially history, actual position and tendencies of development of the doctrine of BS, phenomenology and clinical picture of basic stages, the Bonn Scale for the assessment of dynamic and cognitive basic deficiencies (BSABS) and the importance of this concept for early diagnosis, therapy, prevention and rehabilitation. The patients experience and communicate the BS as deficiencies and are able to cope with, adapt and compensate for them. The BS were termed as basic symptoms because they represent the basis of the productive-psychotic symptomatology. Follow-up studies of cases with the suspicion diagnosis "prodrome of schizophrenia" based on BSABS rating, revealed that the subgroup passing over in schizophrenic psychoses after an average of 6.3 years showed significantly higher scores of cognitive BS at the time of index investigation. It now seems possible to impede increase of cognitive BS already present in prepsychotic prodromal states before reaching the threshold of transition into productive-psychotic symptomatology. Long-term development is more favorable if therapy commences as early as possible including the prepsychotic basic stages and also taking into consideration BS which were, until now, disregarded in DSM-III. Summarizing our findings of the last 30 years we suggest that the BS-concept may be an approach to overcome the dichotomy of negative and positive psychopathology in schizophrenia.