Underdiagnosing and Overdiagnosing Psychiatric Comorbidities

Diagnostic assessment of psychiatric disorders and their comorbidities is a challenge for many clinicians. In emergency settings, there is no time to conduct lengthy interviews, and collateral information is often unavailable. In acute treatment settings, patients may be too symptomatic to provide accurate information or to recall important details that would aid clinicians in deriving a valid diagnosis. In busy clinical practices, clinicians must see a high volume of patients and may not have the luxury of a psychologist on-site to conduct psychological testing or of a psychiatric nurse to administer a structured assessment. Moreover, there are no practical laboratory tests to facilitate the psychiatric diagnostic process.

In addition, acutely ill patients who present for psychiatric care often lack the cognitive ability to explain their symptoms or to describe their symptom progression, and they may not know what historical information might be critical to their doctors’ diagnostic assessments. Therefore, to meet the immediate needs of patients, psychiatrists must use their clinical judgment to make quick assessments, and they must implement treatment with the information available.

Unfortunately, accuracy and thoroughness are sometimes sacrificed for speed. Studies of diagnostic accuracy have demonstrated weaknesses when general clinical interviews are used instead of structured diagnostic methods, which are more common in research clinics.^1-3

There are 3 common problems in diagnosing comorbidities:

• Missed diagnosis. Clinicians may miss coexisting problems that require additional treatment or that interfere with treatment of the primary problem. This usually occurs when clinicians are unable or do not attempt to access sufficient information about the history of illness or do not thoroughly assess concurrent symptoms (eg, not inquiring about symptoms of alcohol(Drug information on alcohol) or substance abuse disorder in a patient who presents with a mood disorder).

• Overdiagnosis. Clinicians may jump to conclusions when a patient presents with a few symptoms that might be indicative of other disorders (eg, assuming the presence of borderline personality disorder in a patient who engages in self-injury or who has outbursts of anger).

• Misinterpretation. Clinicians may misinterpret a symptom and establish an incorrect comorbid diagnosis (eg, observing the theatrical and dramatic behavior of a patient with histrionic personality disorder and mistaking it for hypomania).

Common diagnostic oversights

Substance-related disorders. Clinicians may not ask about alcohol or substance use and abuse when a patient does not fit the stereotype of an addict (eg, those who seem too attractive, intelligent, accomplished, or “well put together” to have a problem with alcohol or drugs).

Age can also hinder the diagnosis of substance-related disorders. Substance use disorder is less likely to be diagnosed in the elderly than in younger adults during an office visit.⁴ This is, in part, because of the overlap between symptoms of substance abuse and symptoms of other physical and mental conditions (eg, stroke, malnutrition, reaction to prescription drugs, depression, dementia).^4,5

Bipolar II disorder. The failure to inquire about a history of hypomania in a patient with major depression can lead to diagnostic and treatment errors.^6-8 Kim and associates⁸ evaluated patients who had received a diagnosis of major depression but who had not received a prior diagnosis of bipolar disorder. Using the Mood Disorder Questionnaire, 53% of this sample was found to have bipolar disorder; 30% had bipolar II disorder.

Schizo-affective disorder or psychotic depression. Clinicians may not assess whether auditory or visual hallucinations are present in patients with major depression who are quiet or pensive, have long response latencies, or are well-groomed and appropriately dressed.

Major depressive disorder (MDD). MDD is commonly overlooked when the clinician assumes that vegetative symptoms of major depression are manifestations of a primary physical illness, such as chronic pain, diabetes, or cancer⁹; dismisses MDD in a patient who has recently suffered a significant loss and does not inquire about symptoms that differentiate MDD from bereavement (ie, excessive guilt, passive suicidal ideation, worthlessness, psychomotor retardation, prolonged functional impairment, or psychosis)¹⁰; or misses concurrent depression in a patient with a primary psychotic disorder.

Posttraumatic stress disorder (PTSD). PTSD is underrecognized in patients with panic disorder, certain phobias, schizophrenia, major depression, alcohol abuse, and antisocial and borderline personality disorders.^11-13

Personality disorders. Because personality disorders share some symptoms with Axis I disorders, they can be easily overlooked (Table 1).¹⁴ Problematic personality traits can interfere with treatment adherence, stress management, and psychosocial functioning.

Cognitive dysfunction. Cognitive decline can interfere with a patient’s ability to follow treatment guidelines (eg, correct medication dosing and consistent appointment attendance) or to manage his or her life and engage in self-care. It may be difficult to identify cognitive dysfunction when marked symptoms of psychosis, mood disorders, or anxiety disorders are present. The repetitive nature of obsessive-compulsive disorder, for example, may mask memory deficits.¹⁵ Forgetfulness in taking daily medication may be mislabeled as resistance. Disorganization and poor planning may be mistaken for impulsivity or an attention deficit consistent with attention-deficit/hyperactivity disorder or bipolar disorder.