What is the likelihood of adverse reactions, including suicidal ideation, during the first Transcranial Magnetic Stimulation (TMS) session?

Adverse Reactions During First TMS Session

Adverse reactions during the first TMS session are uncommon, and there is no evidence that TMS triggers or worsens suicidal ideation—in fact, TMS appears to reduce suicidal thinking even from the first day of treatment. 1, 2, 3

Safety Profile of TMS

Overall Adverse Event Rate

• The risk of serious adverse events during TMS treatment is less than 1% overall, with seizures being the most serious potential acute complication 4
• TMS safety guidelines are primarily focused on minimizing seizure risk, which remains extremely rare even with repeated sessions 1, 5
• There is currently no direct evidence for increased risk of serious or non-serious adverse events from TMS that are causally linked to stimulation 1

Common Side Effects (Not "Bad Reactions")

• Minimal side effects occur during TMS treatment, with most being mild and transient 2
• The most commonly reported side effects include scalp discomfort at the stimulation site and mild headache, but these are generally well-tolerated 1
• In a study of 41 suicidal inpatients receiving intensive TMS (9 sessions over 3 days), the 3-day retention rate was 88%, indicating excellent tolerability even with high-dose protocols 2

Impact on Suicidal Ideation

Evidence Against TMS Triggering Suicidality

• In a large retrospective analysis of 711 patients with depressive disorders treated with TMS, only one patient (0.1%) committed suicide during treatment 3
• Among 332 patients analyzed in detail, 47% showed improvement in suicidal ideation, 41.3% showed no change, and only 11.7% showed any increase in suicidality scores 3
• There is no evidence that rTMS increases the risk for suicide during the course of treatment; conversely, rTMS tends to reduce suicidal ideation 3

Rapid Anti-Suicidal Effects

• Suicidal ideation can decrease rapidly, even after the first day of TMS treatment 2
• In a randomized trial of suicidal inpatients, active TMS showed trends toward more rapid decline in suicidal thinking on day 1 compared to sham (10.7-point decrease vs. 6.4-point decrease) 2
• A meta-analysis found significant decreases in suicidal ideation scores in uncontrolled trials (effect size g = 0.692, P < .001) 6

Specific Risk Factors to Monitor

Factors That May Increase Seizure Risk

While seizures are rare, certain conditions warrant increased vigilance during the first session:

• Substance use: Recent cocaine use, alcohol withdrawal, benzodiazepine/barbiturate withdrawal 1, 5
• Medications: Tramadol use, bupropion (particularly relevant in smoking cessation treatment) 1, 5
• Medical history: History of epilepsy, recent stroke, head trauma, skull defects 5, 4

Safety Monitoring Recommendations

• Comprehensive screening for contraindications should be completed before the first session 5
• Assessment of medication profiles for drugs that may lower seizure threshold 5
• For patients with addiction disorders, consider additional safety monitoring measures such as urinary samples or blood alcohol levels to identify unreported substance use 1

Special Populations

Adolescents with Suicidal Ideation

• High-dose TMS has been successfully used in depressive adolescents with suicidal ideation, with significant lessening of suicidal thoughts 7
• The main caution in adolescents is monitoring for treatment-emergent hypomania/mania, which occurred in 2 of 3 adolescent cases by day 4 of intensive treatment 7

Patients with Traumatic Brain Injury

• TMS has been successfully used in patients with traumatic brain injuries without increased adverse events 4
• Patients with both PTSD and mild traumatic brain injury tolerated intensive TMS protocols (9 sessions over 3 days) with minimal side effects 2

Clinical Bottom Line

The first TMS session is remarkably safe, with serious adverse reactions being exceedingly rare (<1%). 4 The concern about triggering suicidal ideation is not supported by evidence; rather, TMS demonstrates anti-suicidal effects that may begin as early as the first treatment day. 2, 3 Standard safety screening for seizure risk factors is sufficient, and no special precautions beyond established TMS safety guidelines are needed for the first session. 1, 5