Lecture Outline and Learning Objectives

     The fourth edition of the Diagnostic and Statistical Manual of Mental Disorders of the American Psychiatric Association (DSM-IV) is the latest attempt to classify complex phenomena such as various presentations of mental illness into a set of specific disorders that share common characteristics.  The objective of the Diagnostic and Statistical Manual system is to improve reliability and validity among diagnosticians and observers, improve diagnosis, treatment, and research.
     Reliability, remember, is the extent to which different observers agree on a particular diagnosis.   (If they are all wrong, but consistently wrong, they would still have high reliability, just low validity.)  Reliability can be thought of as how closely a series of shots taken with a rifle fall on a target;  even if they are far from the bullseye, if they are close together then reliability will be high.  Reliability can also be viewed as reproducability.
     Validity, on the other hand, is how close the diagnosis of a given instrument falls to some gold standard, or how "correct" it is.  Using the rifle range analogy, validity is how close the shot lands to the bullseye.  Scattered shots centered around the bullseye might have high validity, but low reliability.  Obviously, with subjective phenomena such as mental illnesses, a gold standard is generally lacking.  Agreement between professionals using a clinical interview and some predefined criteria is as close to a gold standard as we can come using today's technology.  Platelet studies, MRI, and PET scans offer some "hard" evidence for some psychiatric disorders, but none is practical as a screening tool.
     Psychiatric researchers must focus on common characteristics, lontitudinal course, reported subjective symptom and observed signs of various illness and empirical evidence to various interventions to determine the validity of an illness or a classification system.
     Before the Diagnostic and Statistical Manual, clinicians used idiosyncratic terms defined in either theoretical or abstract ways.  For example, one's clinician's depressive neurosis might be another clinician's dysthymia.  This made standaradized research of psychiatric disorders almost impossible.  In addition, recently third party payers have become very interested in linking reimbursement to diagnosis; for example, therapy for personality disorders might not be fully reimbursed, whereas treatment of an Axis I disorder (see below) such as major depression would be.  This obviously puts pressure on clinicians to give some diagnoses more than others, thereby diluting the validity of the diagnostic system.
     The Diagnostic and Statistical Manual attempts to be atheoretical and descriptive.  It attempts to rely as much as possible on observed behavior and reported symptoms and does not attempt to explain etiology.  A tremendous effort has been made to incorporate the most recent research findings into the Diagnostic and Statistical Manual, now in its fourth edition (and frequently referred to as DSM-IV).  The DSM-IV is the most widely used diagnostic manual in the United States and one of the most widely used in the world.
     Note that the Diagnostic and Statistical Manual does not address treatment or outcome.

     The Diagnostic and Statistical Manual uses a Five Axis system to help guide the evaluation of the psychiatric patient.
     Axis I includes major psychiatric diagnoses, such as major depression, bipolar disorder (manic depression), schizophrenia, alcohol dependence, or posttraumatic stress disorder.  Traditionally, Axis I disorders are considered by insurance companies and third party payers, to be the most serious psychiatric disorders, even though a severe Axis II disorder can be just as disabling.
     Axis II is where developmental disorders are coded; these include personality disorders and mental retardation.  The Axis I- Axis II dichotomy is somewhat controversial, particularly since an emerging body of evidence indicates a strong biological underpinning to temperament and personality.
     Axis III is where any medical disorders such as hypertension or diabetes are coded.
     Axis IV provides a six point rating scale for psychosocial stressors that contribute to the presentation of the current disorder.  The coding ranges from none to catastrophic:
 

 None: no identifiable stressors.
 Mild:  starting graduate school, having a child leave home.
 Moderate:  marriage, marital separation, loss of job.
 Severe:  divorce, birth of first child, extreme poverty.
 Extreme:  death of  a spouse, serious physical illness, or victim of rape, serious illness in self or child, ongoing sexual or physical abuse.
 Catastrophic:  suicide of spouse, concentration camp victim, natural disaster.

     Note that some judgment must be used here, but there is a tendency to overrate psychosocial stressors.  Most psychiatric patients probably fall in the moderate to severe range of psychosocial stressors.
     Axis V:  Global Assessment of Functioning (GAF):  this is a scale ranging from 0 to 90, 90 being the highest functioning:
 

 GAF:
 90:  no symptoms or dysfunction.
 80: transient symptoms.
 70: mild, e.g., depressive mood or insomnia, mild difficulty in social or occupational functioning.
 60: moderate symptoms, e.g., flat affect, circumstantial speech, panic attacks, moderate difficulty in social or occupational functioning.
 50:  serious symptoms, e.g., suicidal ideation, frequent shoplifting, obsessive rituals.
 40:  some impairment in reality testing or serious difficulty in multiple areas.
 30:  behavior influenced by severe psychiatric symptoms, e.g., delusions, suicidal ideation, or auditory or visual hallucinations.
 20:  some danger of hurting self or others.
 10:  persistent danger to self or others, or complete inability to attend to personal hygiene.
 

[source:  p. 175, Kaplan; DSMIV]