REVIEW S Afr Psychiatry Rev 2005;8:134-139 Major depressive disorder as a co-morbid diagnosis in schizophrenia versus the diagnosis of schizoaffective disorder – depressed type Renata Ronelle du Preez, William Charles Griffith, Mark Page Department of Psychiatry, University of Pretoria, Pretoria, South Africa ABSTRACT The purpose of this article is to focus on the importance of depressive symptoms in patients suffering from schizophrenia, and the dilemma posed by hierarchical classification methods, which exclude co-morbid diagnoses such as Major Depressive Disorder in patients with schizophrenia. The question arises that if Major Depressive Disorder is only categorized under the diagnosis of Schizoaffective Disorder (depressed type), are we able to recognize these symptoms promptly and treat them sufficiently? The duration of the substantial period of depressed mood referred to in the DSM IV TR criteria for Schizoaffective Disorder is unspecified. We suggest that one should only allocate the latter diagnosis if the substantial period is that of one third or more of the whole duration of the illness. Identification of the optimal cutoff point can generate further hypothesis testing research and refinement of the diagnostic model. It is not only important to refine the diagnosis, but it is even more important to detect these symptoms and treat promptly and effectively. According to the latest literature, the best possible treatment for depression in schizophrenia appears to be the combination of a second-generation antipsychotic and cognitive psychotherapy. Keywords: Major depression; Schizophrenia; Schizoaffective; Depressed Received: 29.11.04 Accepted: 28.12.04 Introduction in considering psychiatric diagnoses. Diagnostic categories At present, psychiatry is in a state of flux and advances in defined by their syndromes should be regarded as valid neuroscience and genetics are soon likely to challenge only if they have been shown to be discrete entities with many of its current theoretical underpinnings, particularly natural boundaries that separate them from other disorders. those related to the causation and definition of mental Although most psychiatric diagnostic concepts have not disorders. It is increasingly recognized that the validity of been shown to be valid in this sense, many possess high the diagnostic concepts enshrined in contemporary utility by virtue of the information about outcome, treat- classifications of mental disorders cannot be taken for ment response and etiology that they convey and are granted.1 Indeed Goodwin and Guze2 went so far as to therefore invaluable working concepts for the clinician.1 assert that ‘diagnosis is prognosis’ and referred approvingly According to the diagnostic and statistical manual of to P.D.Scott’s observation that the ‘follow up is the great mental disorders (DSM IV TR)3 diagnostic criteria for exposer of truth…..’ It is to the psychiatrist what the post- schizophrenia, major depressive disorder is excluded and mortem is to the physician. should rather be diagnosed under schizoaffective disorder It is important to distinguish between validity and utility (depressed type). Criteria for schizoaffective disorder (depressed type) state that mood symptoms must be Correspondence: present for a substantial portion of the total duration of the Dr RR du Prezz, Department of Psychiatry, University of Pretoria, active and residual periods of the illness, but they do not PBag X113, Pretoria, 0001, South Africa specify the time period.3 It is suggested that this period email: [email protected] must be clearly defined so as to distinguish between South African Psychiatry Review • November 2005 134 REVIEW S Afr Psychiatry Rev 2005;8:134-139 schizoaffective disorder and the possibility of major Depression may occur in the different phases of the disease, depressive disorder as co-morbid diagnosis. either during the prodromal phase, psychotic phase or post Previously the diagnosis of schizoaffective disorder was psychotic phase. considered confusing and controversial. The different For the latter we at least have the better definition of classifications (ICD-104 and DSMIV TR3) agree that post psychotic depression in schizophrenia in the research schizoaffective disorder presents a combination of schizo- criteria in the DSM IV TR.3 Kohler16 and Jeczmien17 discuss phrenia-like and affective symptoms, but differ as to the post psychotic depression in schizophrenia in their respec- quality, number and time sequence of the symptoms. tive publications and highlight the significant prevalence Hierarchical assumptions at the foundation of the estimated at 25%. Criteria for a major depressive episode diagnostic system stand in the way of recognizing associ- must be met and this episode is superimposed on the ated psychiatric syndromes. It is unclear if associated residual phase of schizophrenia. psychiatric syndromes are separate and distinct co-occur- With regard to depression in the prodromal phases, recent ring or co-morbid syndromes or whether they are part of the research has increasingly focused on the early course of patients’ schizophrenic disorder, i.e. dimensions of schizo- schizophrenia, extending from onset of symptoms to the phrenia that need further attention.5 first treatment contact. A high prevalence of depressive Co-occurring or associated psychiatric syndromes such as symptoms in the early course of schizophrenia has been depression may have been hidden from view by exclusion established in several studies. criteria, which prohibited their being diagnosed in the Hafner et al18 did the so-called ABC schizophrenia study, presence of schizophrenia. a population-based, first –episode study. To study depres- Hierarchical thinking has been present in virtually all sion in the early course of schizophrenia, Hafner’s study systems of psychiatric nosology and has been traced back looked at symptom appearance and accumulation. For this to the tendency in medicine to give each patient only one purpose, four depressive symptoms, without overlap with diagnosis, an approach found in the 17th century. negative symptoms of schizophrenia, namely depressed Bogenschutz6 also emphasized the importance of recogniz- mood, guilt feelings, lack of self-confidence and attempted ing multiple diagnoses in one patient to clarify our thinking suicide were used. about categories of illness and the boundaries between Their findings showed that the prodromal phases lasted them as well as the relationship among these categories. on average for 5 years and in total 81% of patients with first With respect to the categorical versus dimensional episode psychosis did suffer from depressed mood for at argument one false assumption is that the disorder is either least 2 weeks before admission. On average depressive categorical or dimensional whereas in a real sense every mood emerged as early as 52 months before first admission. disorder is both. It is either present or not, but when the Important reasons for investigating depression in schizo- disorder is present patients may vary with respect to age- phrenia involve the influence of these additional symptoms of-onset, severity, symptomatology, impairment, resistance on the quality of life of these patients, as well as the to treatment and the variety of other disorder characteris- introduction of the second- generation antipsychotics with tics. One of the important issues in using categorical their possible antidepressant effect is another important approaches pertains to the choice of a cutoff point from reason.8,109 which the categorical classification is generated.7 The choice for a cutoff point of the duration of depression is The difficulties in diagnosing depression in unclear in schizoaffective disorder and this can lead to schizophrenia erroneous conclusions regarding outcome and stage of Whilst one includes the assessment of hopelessness, illness. suicidality and the degree of depression as central tasks in Identification of an optimal cutoff point must generate a treating affective disorders, this is not always the case for hypothesis, with subsequent research and refinement of patients with schizophrenia. the diagnostic model. Schizophrenic patients present with a myriad of distur- bances in perception, cognition and communication, and The impact of depression in schizophrenia depression can go unnoticed especially during the acute It is a fact that depression occurs in patients with schizo- phase as noted by Knights and Hirsch.19 They introduced phrenia.8,9,10 The studies on depressive symptoms and signs the term “[un] revealed depression” and argued that these in schizophrenia show a variation from between 7 and 65%, symptoms may be unrecognized because of florid psychotic with a modal rate of 25%.11,12 It is clear that these symptoms symptoms. are of considerable clinical relevance and compromise the It is also the legacy of Kraeplin’s division of psychotic level of functioning of these patients, even to the extent of conditions into affective psychoses and dementia praecox. an increased risk of relapse and suicide.9,10,11 This contributed to the belief that schizophrenia and We all are familiar with the facts that schizophrenia depression were and are distinct and non-overlapping reduces the life span of those afflicted by an average of 10 - entities. Yet again this may influence the threshold for 15 years, and suicide is the leading cause of premature diagnosing important depressive symptoms in patients death among patients with schizophrenia.12,13,14,15