Psychology 101: Intro to Psychology

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How do you diagnose something that you can't see? That's the problem faced by psychologists. This lesson will show you the tool they use to help diagnose their patients.

When you go to the doctor with a fever and a sore throat, he'll talk to you, examine you, maybe listen to your breathing; and he'll use this information to figure out an explanation for your symptoms. This explanation is his diagnosis, which is in technical terms his interpretation of the nature and cause of your illness - in other words, what he thinks has gone wrong with you, and why he thinks it's gone wrong. The doctor determines that your sore throat is infected - that's the 'what' - and does a quick swab test to determine that it's caused by the bacteria strep - that's the 'why.'

Diagnosis in psychology is the same thing. If you think about it, though, it can be a lot harder to figure out what's going on in someone's mind than what's going on in their body. You can describe to your doctor that your throat is sore, and he can look at you and run tests to figure out why. If you're depressed, or if you're suffering from hallucinations or delusions, your description of your own symptoms can be more difficult to follow and interpret, and there's no equivalent of a throat swab to test for depression.

Over the years, psychologists have worked hard to figure out ways to improve diagnoses. Psychologist David Rosenhan suspected that psychiatric hospitals often gave patients the wrong diagnoses. To prove it, he decided to send in pseudopatients (including himself) to test the doctors and nurses in the hospitals. These healthy people pretended to be mentally ill by complaining that they heard voices. Once admitted, these pseudopatients acted normal and said their symptoms had stopped. Even so, they were not released and were not identified as having faked their symptoms. After Rosenhan announced these rather embarrassing results, one prominent hospital asked him to send THEM some pseudopatients, confident that in THEIR hospital, the pretenders would easily be identified. Following the challenge, the hospital identified 48 pseudopatients out of the next 195 people who were admitted - but Rosenhan hadn't actually sent anyone! Interestingly, the actual patients in the hospital WERE suspicious of the pseudopatients - it turned out that the patients were better at identifying pretenders than the staff.

Experiments like Rosenhan's show how difficult it is to come up with a reliable scientific system of diagnosing mental illness. For this reason, the Diagnostic and Statistical Manual of Mental Disorders, known as the DSM, has been undergoing constant revision since its creation in 1952.

The current edition is the DSM-IV, with the DSM-V due out in 2013. As psychologists grow in their understanding of symptoms and disorders, they've changed the DSM in order to make it a more effective diagnostic tool. One of the most notable changes to the DSM was the removal of homosexuality from a revised edition of the DSM-III; it had been listed as a disorder since the first edition.

The current DSM-IV uses a system of five axes, or categories of things for the therapist to consider when making a comprehensive diagnosis. Going through these axes, and what kinds of things a therapists marks down for each of them, can help us get a better picture of the many factors involved in psychological health.

Axis I includes clinical disorders, some of which you've probably heard of: depression, bipolar disorder, anxiety disorder, anorexia and schizophrenia, among others. Developmental or learning disorders such as ADHD and autism are included here as well, as are substance abuse disorders such as alcoholism.

Axis II is for intellectual disabilities and personality disorders, such as paranoid personality disorder, borderline personality disorder, antisocial personality disorder and narcissistic personality disorder.

Axis III includes acute medical conditions and physical disorders; since some conditions can affect mental health, therapists record them as a part of the diagnostic process.

Axis IV is where therapists can note social and environmental factors that contribute to the person's overall mental health. These could be things like negative life events, stressful family relationships or inadequate social support.

Axis V is known as the Global Assessment of Functioning. Therapists use this assessment to judge how well a patient carries out the activities of daily living on a scale from 0-100. This completes the patient's psychological profile.

Even though only the things listed on Axis I and II seem familiar to us as psychological problems, all of the information from these axes is important to the therapist when making a diagnoses or planning treatment. For example, let's consider two patients, Wendy and Emily, who have both been marked as having major depressive disorder on Axis I (clinical disorders). Wendy's home life is fine. But Emily's sister has just been diagnosed with cancer, and it's put a lot of stress on her family. Emily's therapist would code this major life event and stressful family relationship on Axis IV (environmental factors), and take this into consideration in Emily's therapy sessions. Wendy's depression and Emily's depression likely have different causes, which the therapist determines by looking at the bigger picture. The DSM actually contains no recommendations for treatment or information about the causes of the clinical and personality disorders listed on Axes I and II because the information on the other axes informs the therapist about both. The American Psychology Association says specifically that the DSM is meant to serve as 'convenient shorthand' for psychological professionals to communicate with one another and reach quick categorizations, rather than a how-to book on fixing patients.

So we've learned about the difficulties of psychological diagnosis through Rosenhan's experiment and the evolution of the DSM. Categorizing, diagnosing and treating mental illness isn't a black and white process. It's important to keep in mind that while the DSM serves as a guide to therapists, it's not the be-all-and-end-all of treatment.