PTSD: Diagnosis

Text adapted from: "The adult patient with posttraumatic stress disorder," in Psychiatry in primary care  by Francesca L. Schiavone and Ruth A. Lanius (CAMH, 2019).

Differential Diagnosis

Although trauma is relatively common, PTSD is less common. In general, lack of a temporal relationship between the trauma and the onset or exacerbation of symptoms, as well as the presence of symptoms that are not included in the diagnostic criteria for PTSD, suggest a disorder other than PTSD.

People with PTSD may present in the course of seeking treatment for another psychiatric illness. Up to 80 percent of people with the disorder have an additional psychiatric disorder, which may be the primary complaint or which may emerge upon taking the patient’s history (Lange et al., 2000). The most common comorbidities are mood and anxiety, substance use and dissociative disorders.

The following section lists disorders that may be confused with PTSD and describes how they differ.

Adjustment Disorders

• Involve a stressor, such as job loss, that does not meet Criterion A for PTSD in the fifth edition of the Diagnostic and Statistical Manual of Mental Disorders (DSM-5; APA, 2013)
• May meet any or all other PTSD criteria

Acute Stress Disorder

• Lasts less than one month
• May or may not develop into PTSD

Major Depressive Disorder

• May include DSM-5 Criterion D and E symptoms (low mood, social withdrawal, distorted negative cognitions)
• Current episode may be precipitated by Criterion A trauma
• Insufficient Criterion B and C symptoms (intrusion and avoidance) to meet full criteria for PTSD

Bipolar Disorders

• Slower mood changes, not linked to traumatic stimuli (Lanius et al., 2016)
• Decreased need for sleep (compared with insomnia or sleep disruption  in PTSD)

Anxiety Disorders and Obsessive-Compulsive Disorder

• Anxiety content not associated with a specific traumatic event

Psychotic Disorders

• Perceptual disturbances not a direct re-experiencing of past trauma
• Greater impairment in reality testing and interpersonal relatedness (Lanius et al., 2016)
• Hearing child voices most likely indicates dissociation rather than psychosis (Dorahy et al., 2009)

Cluster B Personality Disorders

• Prominent emptiness and anger, compared with fear, shame and depression in PTSD (Lanius et al., 2016)
• Onset prior to traumatic event (APA, 2013)

Take a trauma history

Assess for a history of trauma in all patients presenting with psychiatric complaints. Ask about personal experiences of abuse, assault or catastrophic events in childhood and adulthood (Lange et al., 2000). For example, ask:

• “Was there violence in your home during childhood?”
• “Have you ever been exposed to violence as an adult?”
• “Have you ever experienced any unwanted sexual contact in childhood or adulthood?”

Because some patients may not identify their experiences as abusive, if you suspect trauma, it can be useful to ask more generally about how “discipline” was handled in the home, or about “early sexual experiences” (Lanius et al., 2016).

Given the wide range of experiences that can be considered traumatic, it can be worthwhile to ask a more general question, such as “Have you ever experienced any other difficult event that overwhelmed your ability to cope?” With patients at high risk for occupational exposures to trauma, such as first responders, explore the impact of vicarious exposures.

The Adverse Childhood Experiences questionnaire (ACE) assesses for seven types of early-life adversity. It can be used to quantify childhood exposure to trauma (although it does not encompass all types of events that would be considered traumatic). High scores have been associated with adverse health behaviours and outcomes, including cigarette smoking, coronary artery disease and cancer (Felitti et al., 1998). The ACE questionnaire is available for free online here.

Respond sensitively to disclosure

Disclosing a history of trauma can be emotionally evocative, so be careful not to destabilize the patient. Do not probe for excessive detail or extensive recounting of memories because it can trigger decompensation.

Be attentive to the emotions that may emerge during disclosure, and use validating statements; for example, “That sounds like a very difficult experience. How do you think it has affected you? Do you think it is still affecting you now?” Maintain a non-judgmental stance and normalize the wide range of emotions, including shame and numbness. For example, if shame is prominent, say, “Many people who have experienced this kind of event feel shame or blame themselves, even though it was not their fault.”

If a patient becomes significantly dysregulated or re-experiences the trauma during the discussion, reorient the patient to their surroundings and remind them that the traumatic event is not happening in that moment.

Explore symptoms

Once you have established the presence of a Criterion A trauma, explore symptoms further to identify specific ones in each of the four clusters.  A screening instrument such as the PCL-5 can give an initial indication  of the effect of trauma and a roadmap of areas to explore.

Always supplement the screening instrument with clinical judgment and   a clinical interview to elaborate on the symptoms and to ensure you and the patient understand the symptom in the same way (Lange et al., 2000; Lanius et al., 2016). Also screen for the most common comorbidities, namely mood, anxiety and substance use disorders.

Consider specific populations

If some of your patients are refugees, who often have histories of trauma, be alert to the specific challenges of diagnosing PTSD in this population. Refugees have a higher likelihood of complex traumatization involving multiple types of events over a long period, some of which may be unfamiliar to primary care practitioners. Ongoing stressors related to immigration, such as poverty, discrimination and legal issues related to status, may compound the effects of the initial trauma. There is also less data on the validity and appropriate scoring of common screening measures with refugees.

Working with refugees often requires an interpreter, which can affect the clinician–patient relationship and make it more difficult to reach a common understanding of symptoms, particularly given cultural differences in emotional and symptom expression (Nicholl & Thompson, 2004).

In PTSD

• The Primary Care Practitioner Role
• Screening & Assessment
• Diagnosis
• Treatment
  • Pharmacotherapy
• Clinical Tools
• Resources and References