Diagnosing and Classifying Psychological Disorders: DSM-5 and ICD Systems and ICD Comparisons

Psychopathology research begins with the systematic discernment of significant signs and symptoms.
Diagnosis is the process of appropriately identifying and labeling a set of defined symptoms.
A classification system is essential for several reasons:
- It provides a common language for mental health professionals to communicate with each other, with patients, and with the public.
- It serves as a fundamental guide for establishing proper and successful treatment protocols.
- It organizes psychological disorders systematically to allow for scientific study.

The Diagnostic and Statistical Manual of Mental Disorders, Fifth Edition (DSM-5) is the classification system favored by most mental health professionals in the United States.
The DSM-5 was published by the American Psychiatric Association (APA) in $2013$ . Note that the American Psychiatric Association is distinct from the American Psychological Association.
An updated version, the DSM-5 Text Revision (DSM-5-TR), was released in $2022$ .
Each disorder listed in the DSM-5 includes:
- Diagnostic Features: An overview providing a detailed description of the disorder.
- Diagnostic Criteria: Detailed specific symptoms required for a formal diagnosis.
- Prevalence Information: Data regarding what percentage of the population is thought to be afflicted by the disorder.
- Risk Factors: Variables associated with the development of the disorder.

Lifetime Prevalence: This refers to the percentage of people in a specific population who will develop a particular disorder at some point during their lifetime.
Data from the National Comorbidity Survey $2007$ , based on a sample of $9,282$ U.S. residents, indicates that nearly half (approximately $50\%$ )) of all Americans will meet the criteria for a DSM disorder at some point in their lives.
Comorbidity: This is the co-occurrence of two or more disorders in the same individual. Symptoms of comorbid disorders often interact negatively.
- Approximately $41\%$ of individuals diagnosed with obsessive-compulsive disorder (OCD) also meet the diagnostic criteria for major depressive disorder.
- Substance use disorders exhibit high levels of comorbidity with other mental illnesses; $6$ out of every $10$ people with a substance use disorder suffer from another form of mental illness.
- In the most severe cases of mental illness, roughly $25\%$ of individuals also exhibit a substance use disorder.
- Conversely, approximately $10\%$ of those seeking treatment specifically for substance use disorder also have a serious mental illness.
- Individuals with a primary diagnosis of depressive disorder have a better than $50\%$ chance of exhibiting an anxiety disorder, and the reverse is equally true.

When mental illness is comorbid with habitual drug use, symptoms can become exacerbated and more resistant to standard treatments.
Diagnostic clarity is difficult in comorbid cases because it is often unclear if symptoms arise from the mental illness, the drug use, or both.
Best practice for accurate diagnosis involves observing the individual's behavior only after they have ceased drug use and are no longer experiencing withdrawal symptoms.

The DSM has undergone significant revisions since its inception:
- DSM-I ( $1952$ ): Based on a format developed by the U.S. Army during World War II; it included $106$ diagnoses and was $130$ pages long.
- DSM-III ( $1980$ ): Expanded significantly to include $265$ diagnoses over $886$ pages. It began describing disorders in much greater detail.
- DSM-IV: Included $297$ distinct disorders.
- DSM-5 ( $2013$ ): Contains $237$ disorders. While the volume is longer than DSM-IV, the number of listed disorders actually decreased.
Changes in the status of homosexuality reflect shifting perspectives:
- The first two editions of the DSM listed homosexuality as a disorder.
- In $1973$ , the APA voted to remove homosexuality from the manual.
- The DSM-III (1980) introduced "ego-dystonic homosexuality," characterized by same-sex arousal that caused the patient distress and interfered with desired heterosexual relationships. Many saw this as a compromise to appease those who still viewed homosexuality as a pathology.
- In $1986$ , ego-dystonic homosexuality was removed in the DSM-III-R.
Current editions emphasize the importance of gender and cultural differences in how symptoms are expressed and interpreted.

Overpathologizing: Critics argue that the DSM-5 turns common human problems into formal mental illnesses, effectively overpathologizing the human condition.
Diagnostic Hyperinflation: There are concerns that diagnostic criteria have been loosened too much. For example, the DSM-IV included a "bereavement exclusion" for major depressive disorder, stating symptoms should not be attributed to normal grief after losing a loved one. The DSM-5 removed this exclusion, meaning grief and sadness following a death can now be diagnosed as major depressive disorder.

The ICD is published by the World Health Organization (WHO) and was developed in Europe shortly after World War II.
While the ICD and DSM share similar categories and criteria, they serve different primary roles:
- Clinical Diagnosis: Worldwide, the ICD is used more frequently for day-to-day clinical diagnosis.
- Research: The DSM is valued more for research purposes due to its explicit criteria and extensive explanatory text.
- Global Health: The ICD is used to monitor the general health of populations and track the international prevalence of diseases.
The ICD is currently in its 10th edition (ICD-10), with the ICD-11 being developed to harmonize its criteria with the DSM-5 as much as possible.

Psychological disorders represent extremes of inner experiences and behaviors that most people feel occasionally, such as sadness or anxiety. These experiences are only considered disorders when they become extreme and disruptive to life.
Labels should not be used to objectify individuals. Terms like "schizophrenics," "depressives," or "phobics" should be avoided because they promote biased and disparaging assumptions.
A psychological disorder is something a person has, not what a person is.
Like cancer or diabetes, psychological disorders are debilitating, painful conditions that are not of the person's choosing; therefore, those afflicted deserve to be treated with dignity, compassion, and understanding.