W1: Classification of Mental Disorders

How are mental disorders classified?

They are classified by observable behaviours (signs) and self-reported feelings and thoughts (symptoms)

What are the 3 reasons as to why mental disorders should be classified?

1. Provides a common vocab across the different fields

2. Provides a guide for treatment

3. Can be used in legal settings

What are 3 disadvantages to classifying mental disorders?

1. Stigma

2. Changes self-concept (e.g., being ‘abnormal’)

3. Insurance problems

What are the 3 approaches to classification?

1. Categorical

2. Dimensional

3. Transdiagnostic

What is the categorical approach based on?

DSM-V or ICD-11 criteria

How many diagnostic categories are in the DSM-5?

22 categories (including anxiety, OCD, depressive disorder, trauma-and stressor-related disorders, schizophrenia etc)

How do these link: Diagnostic categories, Disorders & Subtypes? (using Anxiety Disorders as example)

What is the DSM disorders trend based on gender?

Higher prevalence of females having DSM disorders than males, except for alcohol abuse

What are 7 limitations of the categorical approach?

1. Arbitrary cutoff thresholds (e.g., 5 vs. 4 symptoms)

2. Makes people believe that the disorder is real, hence they are ‘sick’

3. Ignores overlap between disorders

4. The line between normal and abnormal is not so clean cut

5. Not a fixed set of symptoms

6. Categories don’t always match reality

7. Developed in the Western context (WEIRD countries)

What is an example of a disorder that is proposed for the next DSM?

Internet Gaming Disorder

What is the difference between the categorical and dimensional approach?

• Categorical: Whether one meets a criteria or not (“yes/no”)

• Dimensional: To what extent one meets a criteria (“how much”)

How are mental disorders described using the dimensional approach?

Along a continuum of symptoms

Example: what 4 dimensions does panic disorder involve?

1. Emotional (fear)

2. Cognitive (derealisation, fear of losing control/dying)

3. Behavioural (avoidance of unfamiliar situations)

4. Physical (palpitations, sweating etc)

Example: how does psychosis vary along a continuum?

• Subclinical psychotic experiences (8%)

• Subclinical psychotic symptoms e.g., delusions, hallucinations

• Psychotic disorder

For scoring of symptoms (e.g., MMPI), what is individual’s score on each dimension compared to?

Population norms

What are 3 limitations of the dimensional approach?

1. No common vocab

2. Unwieldly no. of dimensions (too many possible combinations of symptoms)

3. Knowing the severity of the disorder does not impact treatment plan (e.g., high on depression and low on paranoia does not change the treatment)

What do we use for the transdiagnostic approach?

RDoC (Research Domain Criteria)

What assumption/premise is the RDoC based on?

Mental disorders are brain disorders caused by dysfunctional neural circuits, rather that starting with DSM/ICD diagnostic categories

What is one limitation of DoC?

Not for immediate clinical use and will take many years of research before it can influence classification

What are the 5 domains of RDoC?

1. Negative Valence Systems (responses to aversive situations e.g., fear, anxiety)

2. Positive Valence Systems (responses to positive motivational situations e.g., reward seeking, habit formation)

3. Cognitive Systems (attention, memory)

4. Social processes (social behaviour and interpersonal functioning)

5. Arousal/Regulatory Systems (arousal, circadian rhythms)