13- Case 13: Aches and pains and loss of interest

Page: 35-36

Correct answer: C. Major depressive disorder with somatic (melancholic) features

Explanation:
The patient has core depressive symptoms (anhedonia, reduced energy), somatic symptoms (early morning awakening, weight loss), cognitive features (guilt, poor concentration), and symptoms lasting >2 weeks. Normal hemoglobin, ESR, and thyroid function exclude anemia, inflammatory disease, and hypothyroidism. This presentation is most consistent with major depressive disorder with somatic/melancholic features.

Likely diagnosis

A 52-year-old woman presents with 3 months of generalized body aches, non-radiating low back pain, fatigue, early morning waking, weight loss, anhedonia, guilt, and psychomotor retardation. Physical examination is normal. Investigations show:

• Hemoglobin: 13.2 g/dL (reference range 11.7–15.7 g/dL)

• ESR: 9 mm/h (reference range <10 mm/h)

• TSH: 3.5 mU/L (reference range 0.3–6.0 mU/L)

• Free T4: 13.9 pmol/L (reference range 9.0–22.0 pmol/L)

What is the most likely diagnosis?

A. Fibromyalgia
B. Somatic symptom disorder
C. Major depressive disorder with somatic (melancholic) features
D. Hypothyroidism
E. Polymyalgia rheumatica

Correct answer: D. Anhedonia

Explanation:
Core symptoms of depression are:

• Low mood

• Reduced energy

• Anhedonia

Early morning awakening, appetite change, weight loss, and reduced libido are somatic symptoms, not core symptoms.

Core symptoms of depression

Which of the following symptoms is considered a core symptom of depression?

A. Early morning awakening
B. Weight loss
C. Reduced libido
D. Anhedonia
E. Poor appetite

Correct answer: B. Two core symptoms plus three additional symptoms for at least 2 weeks

Explanation:
A diagnosis of depression requires:

• At least two core symptoms

• Plus three or more additional symptoms

• Present for at least 2 weeks

This patient clearly meets these criteria.

Diagnostic threshold for depression

Which of the following best describes the minimum diagnostic threshold for depression?

A. One core symptom plus two additional symptoms for 1 week
B. Two core symptoms plus three additional symptoms for at least 2 weeks
C. Three core symptoms for any duration
D. Four somatic symptoms for at least 1 month
E. Persistent fatigue with normal investigations

Correct answer: B. Early morning awakening, diurnal mood variation, psychomotor retardation

Explanation:
Somatic/melancholic features include:

• Early morning awakening

• Mood worse in the morning (diurnal variation)

• Psychomotor retardation or agitation

• Loss of appetite or weight

These features indicate a biologically driven depressive subtype.

Somatic (melancholic) features

Which of the following symptom clusters best supports somatic syndrome (ICD-10) / melancholic features (DSM-5)?

A. Panic attacks and insomnia
B. Early morning awakening, diurnal mood variation, psychomotor retardation
C. Chronic pain with normal mood
D. Fatigue without mood change
E. Mood worse in the evening

Correct answer: C. To exclude physical causes of depressive symptoms

Explanation:
There is no diagnostic blood test for depression. Investigations are used to exclude medical conditions that can mimic depression, such as:

• Anemia (Hb 13.2 g/dL; normal 11.7–15.7 g/dL)

• Hypothyroidism (TSH 3.5 mU/L; normal 0.3–6.0 mU/L)

• Inflammatory disease (ESR 9 mm/h; normal <10 mm/h)

What this (Anemia (Hb 13.2 g/dL; normal 11.7–15.7 g/dL)) means clinically is:

• Anemia was considered

• Hemoglobin was checked

• The result was normal

• Therefore, anemia was ruled out

It does NOT mean: “The patient has anemia.”

A clearer phrasing would be: “Anemia was considered and excluded (Hb 13.2 g/dL, within normal range).”

Purpose of investigations

Why are investigations most appropriately performed in this patient?

A. To confirm depression biochemically
B. To diagnose fibromyalgia
C. To exclude physical causes of depressive symptoms
D. To monitor antidepressant response
E. To confirm inflammatory arthritis

Correct answer: C. Somatic presentation without obvious psychological symptoms

Explanation:
Depression is significantly less likely to be diagnosed when patients present predominantly with somatic symptoms (e.g., pain, fatigue) rather than overt low mood. This patient initially presents with physical complaints, masking the underlying depression.

Missed diagnosis in primary care

Which factor most commonly leads to underdiagnosis of depression in primary care?

A. Lack of clinician training
B. Female gender
C. Somatic presentation without obvious psychological symptoms
D. Normal blood tests
E. Older age

Correct answer: C. Three or more somatic symptoms should prompt screening for depression

Explanation:
A practical clinical rule of thumb (not a formal diagnostic criterion) is to screen for depression when three or more somatic symptoms are present, regardless of investigation results.

Screening rule (clarification)

Which statement regarding screening for depression in somatic presentations is most accurate?

A. Screening is unnecessary if ESR and thyroid tests are normal
B. Screening should only occur if the patient reports low mood
C. Three or more somatic symptoms should prompt screening for depression
D. Screening replaces formal diagnostic criteria
E. Screening is only valid in psychiatric clinics

Correct answer: C. Melancholic features

Explanation:
ICD-10 uses the term somatic syndrome, while DSM-5 uses melancholic features. They describe the same clinical phenotype.

Terminology clarification

The ICD-10 term “somatic syndrome” most closely corresponds to which DSM-5 specifier?

A. Atypical features
B. Psychotic features
C. Melancholic features
D. Seasonal pattern
E. Catatonia

Correct answer: C. ESR 9 mm/h (normal <10 mm/h)

Explanation:
Polymyalgia rheumatica is typically associated with a markedly elevated ESR. An ESR of 9 mm/h, within the normal range (<10 mm/h), makes this diagnosis very unlikely.

Excluding polymyalgia rheumatica

Which investigation result most strongly argues against polymyalgia rheumatica?

A. Hemoglobin 13.2 g/dL (normal 11.7–15.7 g/dL)
B. White cell count 7.2 × 10⁹/L (normal 3.5–11.0 × 10⁹/L)
C. ESR 9 mm/h (normal <10 mm/h)
D. TSH 3.5 mU/L (normal 0.3–6.0 mU/L)
E. Negative rheumatoid factor

Correct answer: C. Using open-ended questions and linking physical symptoms to stress

Explanation:
Good communication skills—such as open-ended questions, adequate consultation time, and gently linking physical symptoms to psychological stress—significantly improve detection of depression, especially in somatic presentations.

Improving diagnostic accuracy

Which clinician behavior is most likely to improve diagnosis of depression in this patient?

A. Ordering repeated inflammatory markers
B. Prescribing stronger analgesics
C. Using open-ended questions and linking physical symptoms to stress
D. Immediate referral to rheumatology
E. Avoiding discussion of mood

Correct answer: C. Melancholic (somatic) depression

Explanation:
Diurnal variation with morning worsening is a classic biological feature of melancholic (somatic) depression and is uncommon in anxiety or functional somatic disorders.

Diurnal variation significance

A patient with suspected depression reports that her pain and mood are worst in the morning and improve as the day progresses. This pattern most strongly suggests:

A. Anxiety disorder
B. Fibromyalgia
C. Melancholic (somatic) depression
D. Somatic symptom disorder
E. Chronic fatigue syndrome

Correct answer: D. Improves as the day progresses

Explanation:
Pain that improves as the day progresses parallels diurnal mood variation and supports a depressive etiology rather than mechanical or inflammatory back pain.

Pain characteristics in depression

Which characteristic of this patient’s back pain most strongly supports a non-organic (depressive) cause?

A. Located in the lower back
B. Non-radiating
C. Improves when lying down
D. Improves as the day progresses
E. Poor response to NSAIDs

Correct answer: C. Reduced emotional reactivity

Explanation:
Viewing weight loss positively despite illness reflects blunted emotional reactivity, a feature associated with melancholic depression rather than intentional weight control or eating pathology.

Appetite and patient insight

The patient describes weight loss as a “silver lining to the cloud.” This response most strongly reflects:

A. Body image distortion
B. Eating disorder
C. Reduced emotional reactivity
D. Secondary gain
E. Normal coping

Correct answer: B. Long latency before answering questions

Explanation:
Psychomotor retardation is characterized by slowed thinking, speech, and movement, seen here as delayed responses and slow speech.

Psychomotor retardation

Which clinical feature best demonstrates psychomotor retardation?

A. Reduced eye contact
B. Long latency before answering questions
C. Poor sleep
D. Reduced libido
E. Weight loss

Correct answer: D. More common in certain cultural and ethnic groups

Explanation:
Somatic presentations are more common in some cultural and ethnic groups, but they are not exclusive to them and are common across many medical specialties.

Cultural presentation (clarification)

Somatic presentations of depression are:

A. Rare in Western populations
B. Limited to ethnic minorities
C. Equally common across primary and secondary care
D. More common in certain cultural and ethnic groups
E. Diagnostic of somatic symptom disorder

Correct answer: C. Medically unexplained symptoms

Explanation:
A significant proportion of patients in secondary care present with medically unexplained symptoms, many of which are later linked to mood or anxiety disorders.

Medically unexplained symptoms (MUS)

Up to 40% of patients presenting to specialties such as neurology or rheumatology have:

A. Undiagnosed autoimmune disease
B. Factitious disorder
C. Medically unexplained symptoms
D. Somatic delusions
E. Malingering

Correct answer: D. Has no impact on diagnostic validity

Explanation:
Not all somatic symptoms must be present. Reduced libido is not required for a diagnosis of depression or somatic/melancholic subtype.

Libido and diagnosis (clarification)

The absence of reduced libido in this patient:

A. Excludes depression
B. Suggests anxiety instead
C. Weakens the diagnosis significantly
D. Has no impact on diagnostic validity
E. Suggests atypical depression

Correct answer: C. Cognitive symptom of depression

Explanation:
Feelings of guilt and self-blame are cognitive symptoms of depression. They are not delusional unless grossly unrealistic or fixed despite evidence.

Guilt in depression

The patient’s guilt about not wanting to see her grandchildren is best classified as:

A. Delusional guilt
B. Obsessional guilt
C. Cognitive symptom of depression
D. Normal emotional reaction
E. Anxiety-related guilt

Correct answer: C. Somatic presentation masking psychological symptoms

Explanation:
Somatic presentations often require more time to explore psychological contributors, normalize discussion of mood, and avoid premature diagnostic closure.

Role of time in assessment

Which factor most justifies offering this patient a longer GP appointment?

A. Her age
B. Number of investigations required
C. Somatic presentation masking psychological symptoms
D. Need for referral
E. Risk of inflammatory disease

Correct answer: C. Somatic symptoms can precede mood symptoms

Explanation:
In many patients, somatic symptoms precede emotional complaints, making early screening essential even when physical tests are normal.

Key screening principle (advanced)

Which principle best supports screening for depression regardless of investigation results?

A. Depression is a diagnosis of exclusion
B. Normal tests rule out mood disorders
C. Somatic symptoms can precede mood symptoms
D. Depression always presents with low mood
E. Screening increases stigma