Depression. Aaron T. Beck, M.D.

demarcation of the etiology of mental disorders is between internal and external causes. He proposed that there was a natural division between the two major groups of diseases, exogenous and endogenous. In manic-depressive illness, “the real causes of the malady must be sought in permanent internal changes which very often, perhaps always, are innate.” Environment could at most be a precipitant of manic-depressive disease, because by definition an endogenous illness could not at the same time be an exogenous illness.

“The Great Debates”

      The controversy regarding the endogenous-exogenous concept was most prominent in Great Britain, and a number of outstanding authorities took part on both sides of the argument.¹⁸ Earlier, Kraepelin had endeavored to include almost all forms of depression under one label, manic-depressive disorder. Later, German writers almost uniformly split depressions into endogenous and exogenous. The British, however, were sharply divided on this point, and as a result of the clash of opinions in a series of great debates, the concepts of depression were considerably refined (although unanimity has not as yet been attained).

      The first of the debates was touched off by Mapother in 1926, when he attacked the notion of a clinical distinction between neurotic depressions and psychotic depressions. (This argument later shaded into the controversy of endogenous versus reactive depression.) He held that the only reason for making a distinction was the practical difficulties connected with commitment procedures. He claimed that he could “find no other basis for the distinction; neither insight, nor cooperation in treatment, nor susceptibility to psychotherapy.” He attacked the notion that there are neurotic conditions that are purely psychogenic and psychotic conditions that are dependent on structural change. His view was that all depressions, whether ostensibly psychogenic or seemingly endogenous, are mediated by essentially the same means.

      Mapother’s concept is an interesting statement of the phenomenon of depression: “The essence of an attack is the clinical fact that the emotions for the time have lost enduring relation to current experience and whatever their origin and intensity they have achieved a sort of autonomy.” There were a number of rebuttals in the discussion of Mapother’s paper, and then another debate in 1930, which touched off another series of discussions and papers (see Partridge).

      Klein and Wender²³ note that the labels “neurotic,” “reactive,” and “endogenous” depression are beginning to disappear. They speculate that one of the major reasons for their fading is the increasing evidence that diverse types of mood disorders are often triggered by life events, but nonetheless are treatable by “physical methods” (p. 93). However, as reviewed in Chapters 14, 15, and 16, the somatic and psychological therapies overall appear equally capable of providing treatment and prevention of the mood disorders.

Distinction Between Endogenous and Reactive Depressions

      From the various conflicting as well as complementary opinions regarding the validity of differentiating endogenous from reactive or neurotic depressions, it is possible to make a composite picture of endogenous depression as it emerged from the debates. This may be helpful in understanding the referents of the term endogenous, which appeared widely in the earlier literature, although it was not included in any official nomenclature.

      In general, there are two major defining characteristics of the category endogenous depression. First, it was generally equated with psychosis and consequently distinguished from neurotic depressions. Second, it was regarded as arising primarily from internal (physiological) factors and could thus be contrasted with reactive depressions produced by external stress. To complicate the distinctions, however, reactive depressions, although often equated with neurotic depressions, were sometimes distinguished from them.

      The etiology of endogenous depression was ascribed to a toxic chemical agent, a hormonal factor, or a metabolic disturbance.^24,25 Autonomy from external environmental stimuli was considered an essential feature. Crichton-Miller likened the mood variation to the swinging of a pendulum, completely independent of the environment. Neurotic variations in mood, in contrast, were compared to the motion of a boat with insufficient keel, subject to the oscillations in its milieu.

      The specific symptomatology was characterized as a diffuse coloring of the whole outlook, phasic morning-evening variation, continuity, detachment from reality, loss of affection, and loss of power to grieve.²⁶ To this should be added Gillespie’s observation that the symptoms seemed alien to the individual and not congruent with her or his premorbid personality.

      The role of heredity in endogenous depressions was stressed by a number of writers. Gillespie¹⁹ reported that a family history of psychosis was common in this group, and Buzzard²⁶ suggested that suicide and alcoholism were frequent in the family background. Constitutional factors as reflected in body build were emphasized by Strauss.

      Reactive depressions were distinguished from endogenous depressions because they were said to fluctuate according to ascertainable psychological factors.¹⁹ In terms of symptomatology, the distinguishing features were seen to be a tendency to blame the environment and insight into the abnormal nature of the condition.

Systematic Studies

      Several investigators tried to determine whether depressive illnesses are simply drawn from different points along a single continuum, or whether a number of qualitatively distinct entities exist. Kiloh and Garside²⁷ reported a study designed to differentiate between endogenous and neurotic (exogenous) depression. Their article reviewed the historical development of the controversy and the experimental literature and presented data collected by the authors.

      They studied the records of 143 depressed outpatients and abstracted data relevant to their investigation; 31 of the patients had been diagnosed as having endogenous depression, 61 as having neurotic depression, and 51 as doubtful. Thirty-five clinical features of the illness were selected for additional study. A factor analysis was carried out, and two factors were extracted. The first was a general factor; the bipolar second factor was considered by the authors to differentiate between neurotic and endogenous depression. The second factor accounted for a greater part of the total variance than the general factor and was therefore more important in producing the correlations among the 35 clinical features analyzed.

      Kiloh and Garside found significant correlation between certain clinical features and each of the diagnostic categories. The clinical features that correlated significantly (p < .05) with the diagnosis of neurotic depression were, in decreasing order of the magnitude of their correlations, reactivity of depression; precipitation; self-pity; variability of illness; hysterical features; inadequacy; initial insomnia; reactive depression; depression worse in evening; sudden onset; irritability; hypochondriasis; obsessionality. The features that correlated significantly with endogenous depression were early awakening; depression worse in morning; quality of depression; retardation; duration one year or less; age 40 or older; depth of depression; failure of concentration; weight loss of seven or more pounds; previous attacks.

      Another study by Carney et al.²⁸ extended to inpatients the overall approach used by Kiloh and Garside in their study of outpatients. Carney and his coworkers studied 129 inpatient depressives treated with ECT. All patients were followed up for three months, and 108 patients were followed for six months. Initially, all were scored for the presence or absence of 35 features considered to discriminate between endogenous and neurotic depressions. Diagnoses were made before or shortly after treatment was started. Improvement was rated on a four-point scale at the termination of ECT, at three months, and at six months. At three months, only 12 of 63 neurotic depressives (19 percent) were found to have responded well to ECT, whereas 44 of 53 endogenous depressives (83 percent) had responded well.

      A factor analysis of the clinical features produced three significant factors: a bipolar factor “corresponding to the distinction between endogenous and neurotic depression”; a general factor with high loadings for many features common to all the depressive cases studied; and