It was Hippolyte-Marie Bernheim who introduced the term ‘psy-choneurosis’ for hysteria and allied conditions. Freud, who studied with Bernheim, differentiated the ‘actual neuroses’ (including neurasthenia, anxiety neurosis and hypochondria) from the psy-choneuroses. The latter category included not only the ‘transference neuroses’, such as hysteria and obsessive neurosis, but also the psychoses (paraphrenia, schizophrenia, paranoia and manic depres-sion), perversions and neurotic character. Both types of neurosis were related to sexual disturbance; the actual neuroses were direct somatic consequences of a noxious physical influence resulting from misdirected sexual energy; the psychoneuroses were caused by unconscious conflict between instinctual and counter-instinctual forces¹. Although Freud’s thinking on the precise nature of the mental aetiology of the psychoneuroses changed over the years from about 1894 to 1906, he remained consistent in his stance that the psychoneuroses were defined by their aetiology rather than by their phenomenology². Eventually, the psychoses were classified independently, consistent with the views of Kraepelin.

In 1952, the American Psychiatric Association published the first Diagnostic and Statistical Manual of Mental Disorders (DSM-I). It identified the subtypes of psychoneurotic disorders as anxiety, dis-sociative, conversion, phobic, obsessive-compulsive and depressive reactions³. By the mid-1960s, the major diagnostic schemata, ICD-8 and DSM-II, codified the selection of the descriptive framework for identifying the neuroses. Anxiety was seen as the chief characteristic, whether felt and expressed directly or diverted unconsciously into other symptoms. The neuroses were also grouped by severity; they were more specifically symptomatic than the personality disorders, but entailed no gross distortion or impairment of reality testing, as in the psychoses. Categories included in the 300-code section were anxiety, hysterical, phobic, obsessive-compulsive, depressive, neurasthenic, depersonalization and hypochondriacal neuroses. Transient situational disturbances constituted their own category (code 307)⁴.

The descriptive focus was emphasized in ICD-9 with the substi-tution of the term ‘neurotic disorders’ for ‘neuroses’, although the categorization was not significantly modified⁵. In 1980, the Amer-ican Psychiatric Association published the DSM-III⁶, which took a substantial leap towards atheoretical descriptive diagnosis by adopt-ing empirically validated criteria based on research diagnostic cri-teria. One of the most controversial changes was the elimination of the entire class of neuroses. The neurotic disorders were included in the affective, anxiety, somatoform, dissociative and psychosex-ual disorders⁷. The grouping by severity was abandoned in favour of clusters based on similarity of features. The diagnostic entities retained numerical codes compatible with ICD-9 and ICD-9-CM.

The other revolutionary change introduced with DSM-III was the use of a multiaxial system for diagnosis. Under this scheme, personality disorders, which often predispose individuals to the development of specific neurotic (and other) syndromes, were relegated to a separate and parallel Axis II. The 1987 revision, DSM-III-R, changed some names and criteria but retained the same hierarchy of the neurotic disorders and the same multiaxial formula⁸. DSM-IV, published in 1994, was a more substantive revision overall than DSM-III-R, with only a few changes relevant to the neurotic disorders. The diagnosis of Acute Stress Disorder was added for compatibility with ICD-10. Dissociative Identity Disorder was added to Axis I to replace Multiple Personality Disorder, which was removed from Axis II. Simple Phobia was renamed Specific Phobia for compatibility with ICD-10⁹.

Neurotic Disorders in ICD-10 and DSM-IV

The creators of ICD-10 were faced with a formidable challenge, as this version, unlike its nine predecessors, was to be designed as the last of the series to be scheduled for regular revisions¹⁰.It therefore had to contain a format that would allow for flexibility in minor revisions while establishing a more permanent structure than versions 1–9. While following the lead of the phenomenolog-ical school in separating out a major category for mood disorders that includes both psychotic and neurotic levels of severity, it retains the major classification of neurotic disorders, including somatoform disorders and stress-related disorders¹¹. This grouping solves the objection that the term ‘neurosis’ groups together entities which could be better classified, e.g. by placing neurotic types of depres-sion together with other mood disorders, rather than with anxiety disorders. It does, however, retain the historical commonality that traces to Freud’s original stress on the aetiological similarity of the psychoneuroses, acknowledging the current state of scientific knowl-edge that is, at best, ambiguous concerning the aetiology of these disorders^12,13.