Borderline Spectrum and Comorbidity

Borderline Personality Disorder presents a very broad spectrum. It almost seems as though it can encompass all F60 personality disorders within itself.

Criticism of the Term “Comorbidity”

The term comorbidity suggests that one or more disorders exist alongside Borderline Personality Disorder. This may be practical for diagnostic purposes and health insurance billing – but it oversimplifies reality.

Important Distinction

So-called multi-comorbidity is a hallmark of Borderline Personality Disorder. Research has shown that virtually every personality disorder can appear as a comorbidity in this context.

Many professionals therefore now speak of the spectrum of Borderline Personality Disorder, similar to the schizophrenic spectrum.

DSM vs. ICD: Different Classification Systems

DSM-IV: Cluster System

The DSM-IV focuses on the pathological side of the patient and requires that the individual must be impaired by the symptomatology.

Cluster A (odd, eccentric):

• Paranoid Personality Disorder
• Schizoid Personality Disorder
• Schizotypal Personality Disorder

Cluster B (dramatic, emotional, erratic):

• Antisocial Personality Disorder
• Borderline Personality Disorder
• Histrionic Personality Disorder
• Narcissistic Personality Disorder

Cluster C (anxious, fearful):

• Dependent Personality Disorder
• Obsessive-Compulsive (Anankastic) Personality Disorder

ICD-10: F60 Classification

In the ICD-10, all personality disorders fall under F60 (specific personality disorders), except for schizotypal disorder (F21), which is classified within the schizophrenic spectrum.

The average agreement between DSM-IV and ICD-10 is approximately 68%.

Understanding the Borderline Spectrum

Imagine Borderline Personality Disorder as a dimension:

• From inside to outside: different degrees of severity
• The closer to the centre, the more pronounced the distressing symptomatology
• The affected person can be located at any point within the spectrum

When co-occurring comorbidities are added, the spectrum shifts further.

Most Common Co-occurring Personality Disorders

The six most common personality disorders whose symptoms intersect with Borderline Personality Disorder:

1. Schizotypal PD (F21) – Borderline schizophrenia
2. Dependent PD (F60.7)
3. Avoidant PD (F60.6)
4. Paranoid PD (F60.0)
5. Histrionic PD (F60.4)
6. Narcissistic PD (F60.8)

Schizotypal Disorder (F21)

The schizotypal disorder represents a special subtype within Borderline Personality Disorder and is also referred to as borderline schizophrenia.

Symptoms (which can also occur in “episodes” in Borderline):

• Cold affect, anhedonia
• Peculiar and eccentric behaviour
• Tendency toward social withdrawal
• Paranoid or bizarre ideas (without actual delusions)
• Compulsive rumination
• Thought and perception disturbances
• Transient quasi-psychotic episodes with illusions or hallucinations

Note for Family Members

If you have chosen a partner who falls within this area of the borderline spectrum, you are dealing with one of the most extreme areas of the spectrum.

Paranoid Features (F60.0)

In affected individuals who lie relatively close to the centre of the borderline spectrum and within the narcissistic range, paranoid symptoms frequently intrude:

• Excessive sensitivity to rejection
• Holding grudges
• Suspiciousness
• A tendency to interpret neutral actions as hostile
• Combative insistence on one’s own rights
• Pathological jealousy
• Unjustified suspicion regarding sexual fidelity

The “Humane” Combination

A very commonly occurring combination involves individuals with Borderline who also display significant symptoms of:

• Avoidant PD (F60.6)
• Dependent PD (F60.7)

This combination can be described as the more humane variant toward the partner. In this case, symptoms of obsessive-compulsive PD may also be present.

Implications for Diagnosis

The possible combinations of individual symptom profiles within the borderline spectrum are enormously large. Therefore, a differentiated diagnosis should read:

Core diagnosis:

• Borderline Personality Disorder F60.31

Secondary diagnosis:

• a) Strongly pronounced features of Dependent PD (F60.7)
• b) Less pronounced features of Avoidant PD (F60.6)
• c) Less pronounced features of Histrionic PD (F60.4)

Warning Against Diagnostic Inflation

It borders on clinical absurdity to label affected individuals with a diagnosis of F60.31 + xxx + xxx + xxx + xxx, since (almost) all symptoms are part of the borderline spectrum.

ADHD and Borderline

It is important to understand: just because up to 20% of symptomatology overlaps (e.g. poor impulse control), this does not make someone with ADHD an “additional” person with Borderline – and vice versa.

The lack of impulse control in ADHD has biochemical causes, while in Borderline Personality Disorder it is of a structural-psychodynamic nature.

See also: Executive Functions

Conclusion

Borderline Personality Disorder is not a one-size-fits-all condition. Understanding the spectrum and the co-occurring personality disorders helps:

• Affected individuals to understand themselves better
• Family members to contextualise the behaviour
• Therapists to plan individually tailored treatments

Further Information

ICD-10 Criteria Official diagnostic criteria

Narcissism Narcissistic Personality Disorder

Splitting The central defence mechanism

Executive Functions Neuropsychological aspects