The description of primary delusions: confusion in standard texts and among clinicians

A review of standard texts used by trainees reveals a wealth of differences in the description of primary delusions. The views of 52 consultants and trainees were obtained regarding the various descriptions present in textbooks. This demonstrated a high degree of disagreement between clinicians as to which description most clearly matched their own view. A scheme for the classification and description of primary delusions is suggested.

Descriptive psychopathology is a technical lan guage central to psychiatry. However, the defini tion and description of some terms are far from clear, perhaps due to problems in translating from original German texts. Concern over lack of consistent use of terms is not just of academic interest, since a knowledge of descriptive psy chopathology is essential in making consistent diagnoses, and inconsistent usage leads to poor practice and reflects poorly on the psychiatric profession.
The definition, description and categorisation of primary delusions is a case in point. An examination of standard textbooks used by psychiatric trainees reveals a wealth of differ ences in their descriptions. In Kaplan & Sadock's Comprehensive Textbook of Psychiatry. Yager (1989) describes 'primary' delusions as arising "without identifiable precipitating events". In a separate chapter of the same text, Leon et al (1989) give a description of'primary' delusions as "cannot be understood as arising from pre existing psychopathology". This would include Yager's description but is more inclusive. Similar varying descriptions are given by Kendell (1993) in Companion to Psychiatric Studies. Leon et al (1989) further classify 'autochthonous' delusions as a set of 'primary' delusions, arising "as an immediate enlightenment". However, this de scription of 'autochthonous' would directly equate with Yager's (1989) use of the term 'primary'. Indeed, Mullen (1986) in Essentials oj Postgraduate Psychiatry uses the term 'primary' and 'autochthonous' synonymously in referring to delusions. Leon et als (1989) broader concept of 'primary' delusions is shared by Sims (1988) and Fish (1985) who describe 'primary' delusions more specifically as "a new meaning arises in connection with some other psychological event" and that they can be divided into three types, namely 'delusional mood', 'delusional perception' and "the sudden delusional idea" ('autochtho nous delusion']. This is similar to Jaspers (1963) although the latter also includes a fourth type of 'primary' delusion -delusional memories'.
The description of 'delusional perception' as "real perception followed by a delusional mis interpretation of that perception" (Puri & Sklar, 1989) is not contentious. However, the meaning of 'delusional memory' certainly is (Buchanan, 1991). Gelder et al (1989) suggest that 'delu sional memories' are delusional interpretations of real memories. Conversely the Present State Examination describes them as "experiences of past events which clearly did not occur but which the subject equally clearly remembers" (Wing et al, 1974), a view shared by Mullen (1986). Sims (1988) also describes 'delusional memories' as delusions "retrojected in time" and synonymous with 'retrospective delusions'. Sims categorises 'delusional memories' as 'primary delusions', although why this should be the case for retrojected delusions is not clear. Gelder et al (1989) do not comment on whether a 'delusional memory' is a type of 'primary' delusion, although their description seems consistent with this being the case. Fish (1985) presumably thinks of 'delusional memories' as 'primary' delusions, since he divides the former into 'delusional perceptions' and "sudden delusional ideas", based on the ideas of Schneider, and the example he gives of a 'delusional memory' clearly fits the description of Gelder et al rather than that of Sims. If a delusional interpretation is made of a remembered perception, Schneider (1949) ar gues that this is a 'first-rank symptom' since the difference between this type of 'delusional memory' and a 'delusional perception' is simply temporal.
'Delusional mood' is likewise an unclear term, being a difficult translation of the German word wahnstimmung. Gelder et al (1989) state that 'delusional mood' "is an unsatisfactory term because it is really a mood from which a delusion arises". They do not comment on whether or not a 'delusional mood' can be 'primary'. Sims (1988) describes the phenomenon as being a pathologi cal mood, but does not include delusional interpretation as being part of the description. Fish (1985), following Schneider (1949) and Jaspers (1963), refers to a 'delusional mood' as a 'primary' delusion and describes it in a similar fashion to Sims (1988), but then states that a 'delusional perception' and "sudden delusional idea" may arise out of the 'delusional mood'. This seems to imply that 'delusional perceptions' and 'autochthonous' delusions can arise secondary to a psychopathological process and are thus not always forms of 'primary' delusions. This also seems to be implied by the descriptions of Puri & Sklar (1989).
A small survey was undertaken to investigate to what extent the apparent confusion in the description of 'primary' delusions in standard textbooks was evident in a group of consultants and trainees in a single region (Lothian).

The study
A questionnaire was sent to all psychiatric registrars, senior registrars and consultants in Lothian. All those surveyed had passed at least Part I of the MRCPsych examination which includes questions on descriptive psychopathology. The questionnaire asked for the respondents to choose descriptions of various terms that were closest to their own working ideas. The options were worded in such a way as to portray the different views expressed in major psychiatric textbooks used by trainees (see Appendix). They were also asked if various types of delusion were always, sometimes or never 'primary'.

Findings
Fifty-two replies were received from 85 ques tionnaires sent out (61%-see Table 1). There was no significant effect of clinical grade on the replies given. The selection of textbook descrip tions of delusions that were nearest to the views of the clinicians is detailed in Table 2. There was clearly a lack of consensus, particularly regarding the description of 'primary' and 'autochthonous' delusions, with the most popu lar option being chosen by less than two-thirds of respondents. The description of delusional memory given by Sims (1988) was favoured to the alternative by 73%, while 21% chose Gelder et afs (1989) view. The only description with a clear consensus was that regarding delusional mood with 98% agreement.
Autochthonous delusions were felt by 90% to be always primary (Table 3); however, nearly 30% felt that delusional perceptions were some times or never primary. The alternative descrip tion of 'delusional memory' in the literature was reflected by 65% of respondents feeling that they were only sometimes primary. There was a complete spread of views as to whether or not delusional mood was a primary delusion or not.

Comment
This study has many weaknesses including that the clinicians were forced into choosing one of two descriptions when they may have held an alternative view and that the descriptions were not necessarily mutually exclusive. However, it does suggest that the confusion regarding the description of delusions seen in standard text books is reflected in the views of clinicians surveyed.
One way of addressing the question of the description of terminology that has its origins in German existential philosophy is to reopen the debate on existential grounds. While this may be of interest, it would not be of immediate, or practical, benefit to clinicians. Perhaps the question needs to be addressed in a pragmatic way, irrespective of the mechanisms underlying the phenomena. This at least would allow more consistency between psychiatric professionals.
It is suggested that a broad description of 'primary delusions' be adopted stating that they are delusions that arise either spontaneously or as the result of normal psychological processes but not as a consequence of psychopathological processes. Sims (1988) describes ideas as being able to arise in four ways: from perceptions; from a memory; from a mood; and 'out of the blue' or spontaneously.
It follows that 'primary' delu sions could occur in corresponding forms. These would be, using existing terminology: (1) 'Delusional perception' -a normal percep tion followed by a delusional interpretation.
All of the above types of delusions can thus be seen as subtypes of 'primary' delusions. The four types are analogous with those of Jaspers (1963) and this form of terminology is not far from the views of Gelder et al (1989), although the above is more detailed and explicit. However, points raised by different authors need to be addressed, most obviously Sims' (1988) alternative form of 'delusional memory'. When discussing 'delu sional memory', Sims is actually describing the observation that delusions can be retrojected so as to be experienced as if having occurred in the past. Logically, these delusions could be 'pri mary' or 'secondary' and be of any of the forms described above. Therefore it is suggested that the term 'retrojected delusion' be used to de scribe this phenomenon.
'Delusional mood' is a difficult term to de scribe. It is sometimes used, as by Sims (1988), to describe the experience that 'something strange' is happening. However Jaspers (1963) and Fish (1985) both include 'delusional mood' as a primary delusion and it is not clear that Sims' idea of a 'delusional mood' includes the elements of being a fixed, firmly held belief, necessary for the phenomena to be an actual delusion. Another problem with the term and its inclusion as a primary delusion is that if the 'strange' mood is pathological then any delusions arising as a result of it must be 'secondary'. However, just as ideas can arise from a normal 'primary' delusion could do likewise. It is this type of description that is implied in the scheme described here. This leaves open the question of how to refer to the phenomenon of 'something strange' happening. Perhaps it is necessary to resort to using the original German term wahnstimmung and accept that this in itself is not a 'primary' delusion.
The only 'primary' delusions included in Schneider's 'first rank symptoms' of schizophre nia are 'delusional perceptions'. This is fortunate due to the difficulty in classifying patients' descriptions of delusions and because there is perhaps more consistency in the use of this term than others by clinicians. 'First rank symptoms' are no longer accepted as pathognomonic of schizophrenia and it could be argued that the differentiation of 'primary' and 'secondary' delu sions is a fruitless exercise. However, when it is difficult to find two clinicians who agree as to how 'primary' delusions are classified, then questions are raised regarding the use of phenomenology in psychiatric practice. This is not surprising given the confusion evident in standard texts. Perhaps it is time for a discus sion and pragmatic reappraisal of descriptive psychopathology in order to gain greater con sistency between professionals, allowing for more reliable use of objective criteria in clinical diagnoses and research.