Can propranolol (beta-blocker) cause obsessive behavior?

Propranolol and Obsessive Behavior: No Direct Evidence

There is no documented evidence that propranolol causes obsessive-compulsive behavior or obsessions as defined by DSM-5 criteria. However, propranolol can cause psychiatric side effects including psychosis, mania, depression, and sleep disturbances that should be distinguished from true obsessive-compulsive disorder 1, 2, 3, 4.

Documented Psychiatric Side Effects of Propranolol

The established psychiatric adverse effects of propranolol include:

• Mood disturbances: Depression and mood impairments have been documented in adults taking propranolol, though the mechanism involves effects on memory and psychomotor function rather than obsessive thinking 1.

• Sleep-related problems: Sleep disturbances occur in 2-18.5% of patients, including agitation during the night, nightmares, and night terrors—these may be misinterpreted as obsessive rumination but are distinct phenomena 1.

• Psychotic symptoms: Case reports document propranolol-induced hallucinations, paranoid ideations, and severe personality changes that resolved upon drug discontinuation 2, 4.

• Manic symptoms: Propranolol can paradoxically induce manic episodes even at low doses (10 mg), with symptoms including agitation and behavioral changes 3.

Distinguishing True OCD from Propranolol Side Effects

According to DSM-5 criteria, obsessive-compulsive disorder requires specific features that are not reported with propranolol use 5:

• Recurrent intrusive thoughts, urges, or impulses that the patient attempts to neutralize through compulsions
• Time-consuming behaviors (>1 hour per day) aimed at reducing anxiety
• The disturbance must NOT be attributable to the physiological effects of a medication 5

If a patient on propranolol develops what appears to be obsessive behavior, consider alternative explanations:

• Agitation or restlessness from sleep disturbances rather than true obsessions 1
• Psychotic symptoms with repetitive behaviors (which would be delusional, not obsessive) 2, 4
• Manic symptoms with goal-directed hyperactivity (distinct from compulsions) 3
• Pre-existing anxiety disorder being unmasked or worsened

Clinical Management Algorithm

If behavioral changes emerge on propranolol:

1. Assess the specific symptoms: Determine whether the behavior meets criteria for obsessions/compulsions versus other psychiatric phenomena 5.

2. Consider drug discontinuation: Most propranolol-induced psychiatric symptoms resolve rapidly after stopping the medication 2, 4.

3. Switch to cardioselective beta-blocker if needed: Atenolol or metoprolol may avoid CNS effects since they are less lipophilic and cross the blood-brain barrier less readily 2.

4. Avoid abrupt discontinuation: Taper propranolol to prevent rebound symptoms, particularly in patients using it regularly 1, 6.

Important Caveats

• The evidence base consists primarily of case reports for psychiatric side effects, making it difficult to establish causation definitively 2, 3, 4.

• Interestingly, propranolol has been used therapeutically to treat agitation and aggressive behavior in dementia at low doses (10-80 mg/day), suggesting its behavioral effects are complex and dose-dependent 7.

• No evidence suggests propranolol causes the specific syndrome of obsessive-compulsive disorder as defined by modern diagnostic criteria 5.