Depression differential diagnoses

Medications that have been used as treatment for anxiety and depression in the postwithdrawal state include antidepressants, benzodia2epines and other anxiolytics, antipsychotics, and lithium. In general, the indications for use of these medications in alcoholic patients are similar to those for use in nonalcoholic patients with psychiatric illness. However, following careful differential diagnosis, the choice of medications should take into account the increased potential for adverse effects when the medications are prescribed to alcoholic patients. For example, adverse effects can result from pharmacodynamic interactions with medical disorders commonly present in alcoholic patients, as well as from pharmacokinetic interactions with medications prescribed to treat these disorders (Sullivan and O Connor 2004). 

Reproduced from [38, 39] with permission Tab. 19.3 Differential diagnosis of depression... 

Patients with depression usually do not present initially to mental health professionals. Most visit their primary care physicians, complaining not of depressed mood but of other symptoms of depression. Fatigue, insomnia, loss of appetite, loss of interest in sex, muscle tension, body aches, and poor concentration are all commonly reported. These so-called masked presentations of depression may in part explain the documented failure of primary care physicians to diagnose depression reliably. This underscores the importance of considering depression in the differential diagnosis of physical complaints that appear vague or exaggerated. 

The differential diagnosis of depression is organized along both symptomatic and causative lines. Symptomatically, major depression is differentiated from other disorders by its clinical presentation or its long-term history. This is, of course, the primary means of distinguishing psychiatric disorders in DSM-1V. The symptomatic differential of major depression includes other mood disorders such as dysthymic disorder and bipolar disorder, other disorders that frequently manifest depressed mood including schizoaffective disorder, schizophrenia, dementia, adjustment disorder, and post-traumatic stress disorder, and, finally, other nonpsychiatric conditions that resemble depression such as bereavement and medical illnesses like cancer or AIDS. 

Primary care physicians are critical to the successful identification of GAD. Characterized by often-vague physical complaints, GAD must be distinguished from medical illnesses and other psychiatric disorders, though the high rate of comorbidity requires that a thorough evaluation for GAD be completed even when another disorder has been identified. GAD warrants particular consideration for those patients with nonspecific physical complaints who nevertheless have an urgent need for relief that has resulted in repeated office visits. The differential diagnosis for GAD includes other anxiety disorders, depression, and a variety of medical conditions and substance-induced syndromes. 

These patients will often present with complaints of depressed mood or anxiety. The depression frequently takes the form of dysthymic disorder although these patients are at increased risk for major depressive disorder as well. Anxiety is often a symptom of the personality disorder itself, though comorbid Axis 1 anxiety disorders are occasionally present. Similar to the other personality disorders, there is a differential diagnosis that should be considered in patients who have a Cluster C personality disorder. 

A family history of mental disorders should be gathered, but the identification of mental disorders in family members becomes less reliable when it moves beyond the person directly interviewed. Family history can be useful in narrowing the differential diagnosis and in interpreting potential comorbidity. For instance, consideration of the potential contribution of depression or hypomania to ADITD can be aided if there is a family history of affective disorder. A family history of certain disorders such as tics may also be helpful in selecting and monitoring medications. 

A normal response is an increase in plasma TSH of 5 to 15 pU/mL above baseline. A response of less than 5 pU/mL above baseline is generally considered to be blunted (some laboratories consider a response below 7 pU/mL to be blunted) and may be consistent with a major depression. An abnormal test is found in approximately 25% of patients with depression. A blunted TSH response (especially in conjunction with an abnormal DST) may help in confirming the differential diagnosis of a major depressive episode and support continued antidepressant treatment. An increased baseline TSH or an augmented TSH response (higher than 30 pU/mL), in conjunction with other thyroid indices, might identify patients with hypothyroidism, mimicking a depressive disorder. These patients may benefit most from thyroid replacement therapy. 

A depressive episode may result from a diverse group of psychiatric and nonpsychiatric conditions ( Table 6-2) that differ in their natural course as well as in their response to treatment. Hence, a differential diagnosis is critical to the workup of an episode. 

Given this context, it is not surprising that general physicians find psychiatric differential diagnosis difficult. Whether there is a unique condition consisting of mixed anxiety and depression is not known, but before it is added to our nomenclature, there should be evidence supporting its construct validity. The following are the standard tests of such validity ... 

Pope H, Lipinski J. Differential diagnosis of schizophrenia and manic depressive illness a reassessment of the specificity of schizophrenia symptoms in the light of current research. Arch Gen Psychiatry 1978 35 811-828. 

Davis JM, Noll KM, Sharma R. Differential diagnosis and treatment of mania. In Swann AC, ed. Mania new research and treatment. Washington, DC American Psychiatric Press, 1986 1-58. Mendlewicz J, Fieve RR, Rainer JD, et al. Manic-depressive illness a comparative study of patients with and without a family history. Br J Psychiatry 1972 120 523-530. 

After the consensus of ESC/ACC was reported (Alpert et al, 2000), the differential diagnosis between UA and non-Q-wave infarction has been especially based on the rise of troponines. Nevertheless, it should be borne in mind that a small number of patients with ST-segment depression may end up with a Q wave infarction (Figure 8.2). 

Hypomania is a less severe form of mania, and by dehnition does not cause a marked impairment in social or occupational functioning, and no delusions or haUucinations are present. " Patients with hypomania often do not seek treatment imtil they have a depressive episode, thus hypomania may not be recognized or reported. Symptoms found in hypomanic episodes are similar to those of cocaine- or antidepressant-induced mood disorders thus the differential diagnosis should rule out any substance-induced or medical conditions that present with elevated mood. Hypomanic states should be closely monitored, because 5% to 15% of patients may rapidly switch to a manic episode." ... 

Edrophonium is an anticholinesterase muscle stimulant that facihtates myoneural junction impulse transmission by inhibiting acetylcholine destmction by cholinesterase. It is indicated in differential diagnosis of myasthenia gravis as an adjunct in evaluating treatment of myasthenia gravis in evaluation of aner-gency treatment of myasthenic aises in reversal of neuromuscular blockade by curare gallamine or tubo-curarine and in treatment of respiratory depression caused by curare overdose. 

IV. Diagnosis is usually based on the history of ingestion and findings of CNS depression, often accompanied by muscle twitching or hyperreflexia. The differential diagnosis should include other sedative-hypnotic agents (see p 335). 

IV. Diagnosis is based on the history of exposure and typical findings of CNS depression and metabolic disturbances. The differential diagnosis is broad and in-oludes most CNS depressants. Encephalopathy and hyperammonemia may mimio Reye s syndrome. 

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