In a male patient with erectile dysfunction, how should I evaluate whether low testosterone or post‑traumatic stress disorder is the underlying cause and what is the appropriate initial management?

Distinguishing Low Testosterone from PTSD as the Cause of Erectile Dysfunction

Measure morning serum total testosterone immediately and perform a comprehensive sexual and psychosocial history focusing on trauma exposure, nocturnal erections, and libido—both conditions commonly coexist and require simultaneous evaluation rather than sequential testing. 1, 2

Key Diagnostic Distinctions

Clinical History Features That Differentiate the Causes

Loss of libido strongly suggests testosterone deficiency or depression/PTSD, while preserved libido with isolated erectile difficulty points more toward psychogenic or vascular causes. 2

• Nocturnal and morning erections: Their presence suggests (but does not confirm) a psychogenic component such as PTSD, though this finding is not definitive. 1
• Masturbatory erections: Preserved masturbatory function similarly indicates psychogenic etiology. 1
• Situational factors: ED occurring only with specific partners or in specific contexts (e.g., only when triggered by trauma reminders) points toward PTSD. 1
• Onset pattern: Sudden onset with concurrent loss of libido makes testosterone deficiency highly likely and treatable. 2

Trauma and Psychiatric Screening

Screen systematically for PTSD symptoms, depression, anxiety, relationship conflicts, and recent life stressors, as these are essential components of the evaluation. 2

• PTSD is associated with pervasive sexual dysfunction across all domains (desire, arousal, orgasm, activity, and satisfaction), not just erectile function. 3
• High correlation exists between sexual dysfunction in PTSD patients and anger-hostility symptoms. 3
• Performance anxiety and relationship issues are common psychological contributors that may be primary or secondary to ED. 1

Laboratory Evaluation

Measure morning serum total testosterone in all men with ED—this is a moderate recommendation with Grade C evidence and should never be delayed when ED presents with loss of libido. 1, 2

• Testosterone deficiency is defined as total testosterone <300 ng/dL with presence of symptoms and signs. 1
• Free testosterone or androgen index is preferred over total testosterone alone and can prevent unnecessary endocrine investigation in up to 50% of men with low total testosterone. 4
• If testosterone is low, measure luteinizing hormone and prolactin. 4
• Perform baseline metabolic testing including fasting glucose or HbA1c and lipid profile to screen for diabetes and cardiovascular risk. 4

Critical Pitfall to Avoid

Do not delay testosterone testing when ED presents with loss of libido—the combination makes testosterone deficiency highly likely and immediately treatable. 2

Initial Management Algorithm

If Testosterone Deficiency is Documented

Treat testosterone deficiency first in men with documented low testosterone and symptoms of hypogonadism. 2

• Testosterone replacement therapy improves both erectile function and libido in hypogonadal men. 2
• PDE5 inhibitors are more effective when combined with testosterone therapy in men with testosterone deficiency. 1
• Testosterone therapy alone is not effective monotherapy for ED—if the goal is amelioration of ED symptoms, counsel regarding the need for ED therapies in addition to testosterone therapy. 1

If PTSD is the Primary Diagnosis

Offer referral to a mental health professional as either an alternative or adjunct to medical treatment, focusing on psychotherapy and psychosexual counseling. 1

• Do not assume psychogenic ED requires only counseling—PDE5 inhibitors work for both psychogenic and organic ED and should be initiated concurrently with psychological therapy. 2
• Sildenafil (50-100 mg) has been shown effective in treating ED in PTSD patients in placebo-controlled trials, though the effect is marginal and patients may still meet ED criteria after treatment. 5
• When depression is present, address the underlying psychiatric condition as essential—antidepressants themselves may worsen sexual function. 2

If Both Conditions Coexist

Treat both simultaneously rather than sequentially, as testosterone optimization may improve response to PDE5 inhibitors. 2

• Many PTSD patients are treated with SSRIs, which significantly exacerbate sexual dysfunction including desire, arousal, and frequency of sexual activity. 3
• Consider medication adjustment if SSRIs are contributing to sexual dysfunction. 3

First-Line Pharmacologic Treatment

Prescribe PDE5 inhibitors as first-line treatment regardless of whether the etiology is organic, psychogenic, or mixed. 1, 2

• Start conservatively and titrate to maximum dose, requiring at least 5 separate attempts at maximum dose before declaring treatment failure. 2
• Carefully instruct patients that sexual stimulation is necessary and that more than one trial may be required to establish efficacy. 1
• PDE5 inhibitors are effective in 60-65% of men with ED. 2

Cardiovascular Risk Assessment

Counsel all men with ED that it is a risk marker for underlying cardiovascular disease, even without cardiac symptoms, and communicate this to the primary care provider. 1

• ED is as strong a predictor of future cardiac events as cigarette smoking or family history of myocardial infarction. 1
• Do not treat ED without addressing cardiovascular risk—men with organic ED should be considered at increased cardiovascular disease risk until proven otherwise. 2

Lifestyle Modifications

Recommend smoking cessation, weight loss if BMI >30 kg/m², increased physical activity, reduced alcohol consumption, and optimization of blood pressure, lipids, and glycemic control. 2