Head pain and psychiatric illness: Applying the biopsychosocial model to care

More than 45% of people worldwide suffer from headache at some point in their life.¹ Head pain can lead to disabil­ity and functional decline, yet headache disorders often are underdiagnosed and poorly assessed. For example, 60% of migraine and tension-type headaches go undiagnosed and 50% of persons suffering from migraine have severe functional dis­ability or require bed rest.^2-4

Because head pain can be associated with secondary medical and psy­chiatric conditions, diagnosis can be challenging. This article reviews the medical and psychological aspects of major headaches and assists with clinical assessment. We present clinical interviewing tools and a diagram to enhance focused, efficient assessment and inform treatment plans.

Classification of headache
Headache is a common complaint, yet it is often underdiagnosed and ineffectively treated. The World Health Organization estimates that, globally, 50% of people with headache self-treat their pain.⁵ The International Headache Society classifies headache as primary or sec­ondary; approximately 90% of complaints are from primary headache.⁶

Assessment and diagnosis of headache can be complex because of overlapping, subjective symptoms. It is important to have a general understanding of primary and secondary causes of headache so that interrelated symptoms do not obscure the most accurate diagnosis and effective treatment course. Although most headache complaints are benign, ruling out secondary causes helps gauge the likelihood of developing severe sequelae from underlying pathology.

By definition, primary headaches are idiopathic and commonly include migraine, tension-type, cluster, and hemicrania conti­nua headache. Secondary headaches have an underlying pathology, which could improve by targeting the disorder. Common secondary causes of headache include:
• trauma
• vascular abnormalities
• structural abnormalities
• chemical (including medications)
• inflammation or infection
• metabolic conditions
• diseases of the neck and pericranial and intracranial structures
• psychiatric conditions.

Table 1 illustrates common causes of head pain. More definitive criteria for symptoms and diagnosis can be found in the International Classification of Headache Disorders.⁷

Primary headache
Tension-type is the most common pri­mary headache, accounting for more than one-half of all headaches.⁷ Patients usually describe a tight pain in a bilateral band-like distribution, which could be caused by sustained neck muscle contraction. Pain usually builds in intensity and can last 30 minutes to several days. There is a well-established association between emotional stress or depression and the development of tension-type headaches.⁸

Migraine typically causes pulsating pain in a localized area of the head that lasts as long as 72 hours and can be associated with nausea, vomiting, photophobia, phono-phobia, and aura. Patients report varying precipitating factors but commonly cite cer­tain foods, menstruation, and sleep depri­vation. Although rare, migraine with aura has been linked to ischemic stroke; most cases have been reported in female smokers and oral contraceptive users age <45.⁹

Because migraines can be debilitat­ing, some patients—typically those with ≥4 attacks a month—opt for prophylactic medication. Effective prophylactics include amitriptyline, propranolol, divalproex sodium, and topiramate, which should be monitored closely and given a trial for sev­eral months before switching to another drug. Commonly used abortive treatments include triptans and anti-emetics such as metoclopramide.

Meperidine and ketorolac are popular second-line agents for migraine. Botulinum toxin A also has been used in severe cases to reduce the number of headache days in chronic migraine patients.⁶

Cluster headache is rare, but typically exhibits repeated burning and intense unilateral periorbital or retro-orbital pain that lasts 15 minutes to 3 hours over several weeks. Men are predominantly affected. Cluster headaches typically improve with oxygen treatment.

Biopsychosocial model of head pain
The biomedical model has helped iden­ tify pathophysiological pain mechanisms and pharmacotherapeutic agents for headache. However, during assessment, limiting one’s attention to the linear rela­tionship between pathology, mechanism of action, and pain oversimplifies common questions clinicians face when assessing chronic head pain.

Advancements in the last 3 decades have expanded the conceptualization of head pain to integrate sociocultural, envi­ronmental, behavioral, affective, cogni­tive, and biological variables—otherwise known as the biopsychosocial model.^10,11 The biopsychosocial model is a multidi­mensional theory that helps answer dif­ficult clinical assessment questions and complex patient presentations (Table 2).^10-13 Many unusual responses to pain treatment, questionable validity of pain behavior, and disproportionate pain perception and functional decline are explained by non-pathophysiological and non-biomechani­cal models.

Psychiatric comorbidity and head pain
Psychiatric conditions are highly prevalent among persons with primary headache. Verri et al¹⁴ found that 90% of chronic daily headache patients had ≥1 psychiatric con­dition; depression and anxiety were most common. Of concern, 1 study found that headache is associated with increased frequency of suicidal ideation among patients with chronic pain.¹⁵ It is critical for clinicians to screen for psychiatric comor­bidities in patients with chronic head­ache. Conversely, clinicians might want to screen for headache in their patients with psychiatric illness.