According to the DSM -- IV -- TR (2000), Major Depressive Disorder is classified by the number of Major Depressive Episodes -- although only one is needed in order to diagnose Major Depressive Disorder -- and according to the severity, ranging from mild, moderate, severe without psychotic features, or severe with psychotic features (347). This means that, in practice, the signs or symptoms of Major Depressive Disorder are those of a Major Depressive Episode: the clinician is required to diagnose the Episode before the larger diagnosis of the Disorder is indicated. In order to diagnose a Major Depressive Episode, there must be present a mood which is obviously depressed, which can also be observed as simply the loss of interest in nearly all activities, or the absence of accustomed pleasure -- sometimes known by the more clinical term "anhedonia" -- in familiar activities (349). However, the DSM-IV-TR specifies that the length of time of this mood must be "a period of at least 2 weeks" (349). This is the most salient feature of the condition, and without this no further attempt at diagnosis should proceed. However, this clearly fits under the heading of common sense: the patient must exhibit a depressed mood, or at the very least a mood in which interest and pleasure in "nearly all activities" have vanished (349).
Having identified an overall depressed mood in the patient according to these criteria, however, the clinician is then required to measure the patient against a checklist, in which "at least four additional symptoms" must be present for the situation to qualify as a Major Depressive Episode (349). The first and second of the listed symptoms are what has already been described, one of which is necessary for the diagnosis. The first is the depressed mood, which may or may not be acknowledged by the patient. The patient's subjective description can take a number of forms, describing the mood as "depressed, sad, hopeless, discouraged, or 'down in the dumps'." (349). But the patient is also in some cases likely to deny the mood, in which case the clinician might attempt to gain an admission by interview or infer the mood "from the person's facial expression and demanor" (349). It is also worth noting that some patients will either report or demonstrate a mood which appears "irritable or cranky" -- this is particularly noteworthy in children and adolescents, where Major Depressive Disorder will often present this type of mood, although it must not be confused with the sort of irritability a child or adolescent might demonstrate when merely frustrated (349). The second of the two necessary diagnostic criteria is the anhedonia, or "loss of interest or pleasure" in daily activities -- this is, in some way, "nearly always present" (349). As a result, one of these first two criteria on the diagnostic list is necessary to make the further diagnosis.
Of the subsequent symptoms on the diagnostic list, it is necessary for the patient to exhibit at least four out of the remaining seven in order to warrant a diagnosis of Major Depressive Episode. We can examine these symptoms in the order they appear on the diagnostic list. The third symptom, Criterion A3, is related to weight or appetite: the clinician is instructed to look for noticeable weight loss (when the patient is not on a diet) or weight gain, or else a daily increase or decrease in appetite (350). The DSM notes that, in practice, the "appetite is usually reduced" (349). But obviously the noticeable weight gain or loss is generally related to the change in appetite, although relying upon weight as the diagnostic criterion here may relate to the occasional unwillingness of patients having a Major Depressive Episode to acknowledge or share their subjective experiences.
The fourth symptom, Criterion A4, can be generally termed as "sleep disturbance" (350). This means the presence of either insomnia or hypersomnia (excessive sleep) almost every day. But in terms of how commonly this symptom may present itself, it is worth noting that insomnia is the "most common sleep disturbance associated with a Major Depressive Episode" (350). Most often the type of insomnia is "middle" or "terminal" -- i.e., the patient wakes up in the middle of the night and has difficulty getting back to sleep, or the patient wakes up too early and is unable to return to sleep at all -- although less commonly patients may complain of "initial" insomnia, i.e., a difficulty in falling asleep (350). Hypersomnia is less common, but can also be a valid symptom. The sleep disturbance is crucial because, once again, given the frequent unwillingness of patients with a Major Depressive Episode to acknowledge their symptoms, the clinician will sometimes find that the stated reason for seeking treatment is the sleep disturbance, rather than a more obvious acknowledgement of depression.
The fifth symptom on the list, Criterion A5, is a change in psychomotor activity -- either retardation (slowing down) or agitation (feelings of restlessness). The restlessness can take many forms -- "inability to sit still, pacing, hand-wringing; or pulling or rubbing of the skin, clothing, or other objects" (350). The retardation can be observed as a slowing down of speech, thought, or movement, or various other changes in speech pattern, ranging from "increased pauses" to complete "muteness" (350). The crucial thing about this particular diagnostic criterion is that, in this case, the clinician cannot rely on the patient's "subjective feelings," but the agitation or retardation must be significant enough to be "observable by others" (350). However, it is possible for there to be a certain amount of diagnostic overlap with the retardation component of Criterion A5 and the overall substance of the next symptom, Criterion A6, which specifies fatigue or loss of energy nearly every day. Again, this has to be significant and observable, with the patient reporting "sustained fatigue without physical exertion" (350). The specific example offered by the DSM for this criterion is a patient who complains that "washing and dressing in the morning are exhausting and take twice as long as usual" (350). In this case, the element of duration -- in which these simple activities seem to take twice as long to accomplish -- can possibly give the clinician an indicator for the previous criterion of psychomotor retardation. But the patient's sense that even simple activities cause fatigue is the clear sign of this criterion -- which, as with all of these symptoms, must be present (and present more or less every day) for at least a 2-week period before the examination in order to qualify as a Major Depressive Episode.
The final three criteria are all cognitive in character. The seventh diagnostic criterion, A7, specifies a "sense of worthlessness or guilt," which can for example take the form "unrealistic negative evaluations of one's worth or guilty preoccupations or ruminations over minor past failings" (350). It is also worth noting that this particular symptom can, in fact, take on "delusional proportions" -- in other words, a patient is convinced that "he or she is personally responsible for world poverty" (350). But in terms of evaluating the patient for this particular criterion, the DSM-IV-TR also specifies that it is not sufficient that the patient blames himself or herself for the illness and for failure to meet job-related or personal responsibilities as a result of the illness -- this is such a common response to the illness itself that it should be regarded as a standard element of the first criterion, of the generalized depressed mood. The next of the cognitive diagnostic criteria, A8, is a diminished ability to think or concentrate, or indecisiveness, observed on a daily basis. As with other criteria for a Major Depressive Episode, the patient's unwillingness to admit to various aspects of thought or behavior means that this can be diagnosed by the observations of others, even if the patient fails to admit it. This impaired ability to think can frequently take the form of "memory difficulties" or "concentration problems" -- in children, it may be reflected by poor academic performance, and in elderly patients it very frequently takes the form of memory problems where the clinician must be careful not to mistake it for dementia (350). In fact, depression-related memory problems in the elderly can, by the frequency of occurrence, be labeled as "pseudo-dementia" because, when the patient is properly treated for depression, the "memory problems often fully abate" (350). And the final cognitive criterion, A9, relates to "recurrent thoughts of death" or suicide, and various forms of suicidal ideation or behavior. The clinician is warned, however, that "the frequency, intensity and lethality of these thoughts can be quite variable" (351). In other words, the thoughts of death can be transient ideation, once or twice a week, or they can be part of an actual plan (including the requisite materials) with a constant recurrent fixation on the idea of self-harm or death.
These 9 criteria are the first step in diagnosing a Major Depressive Episode…