What additional medications can be given to a 16-year-old female patient with Persistent Depressive Disorder, Post-Traumatic Stress Disorder, and Borderline personality traits, currently on Fluoxetine (Selective Serotonin Reuptake Inhibitor), Aripiprazole (Abilify) (Atypical Antipsychotic), Propranolol (Beta Blocker), and Quetiapine (Atypical Antipsychotic), who continues to experience suicidal ideations and self-harm behaviors?

Additional Medications for Persistent Suicidal Ideation in Adolescent with Treatment-Resistant Depression

Given this patient's persistent suicidal ideations despite adequate doses of fluoxetine and aripiprazole, lithium augmentation should be added immediately as it provides the strongest evidence for reducing suicide risk, with an 8.6-fold reduction in suicide attempts and 9-fold reduction in completed suicides—effects that are independent of its mood-stabilizing properties. 1, 2

Primary Recommendation: Lithium Augmentation

Start lithium carbonate 300mg twice daily (600mg/day total), targeting serum levels of 0.8-1.2 mEq/L for acute treatment. 1, 2 This dosing strategy is specifically recommended for adolescents age 12 and older with suicidal behavior. 1

Critical Safety Protocols for Lithium in Suicidal Patients

• Implement mandatory third-party medication supervision where a responsible adult (mother in this case) dispenses only daily doses, stores all medications securely, and monitors for any unexpected mood changes or side effects. 1, 2, 3
• Prescribe limited quantities with frequent refills to minimize stockpiling risk, as lithium overdoses can be lethal. 1, 4
• Parents must be explicitly instructed to secure lithium and remove access to lethal quantities. 4

Required Baseline Laboratory Monitoring

Before initiating lithium, obtain: 1, 4

• Complete blood count
• Thyroid function tests (TSH, free T4)
• Urinalysis
• Blood urea nitrogen and creatinine
• Serum calcium
• Pregnancy test (if applicable)

Ongoing Monitoring Schedule

• Check lithium level after 5 days at steady-state dosing, then every 3-6 months once stable. 1, 4
• Monitor renal function (BUN, creatinine) and thyroid function every 3-6 months. 1, 4
• Assess for lithium toxicity symptoms at each visit (tremor, confusion, polyuria, polydipsia). 1

Adjunctive Psychotherapeutic Interventions

Dialectical Behavior Therapy (DBT)

DBT should be initiated immediately as it provides the strongest evidence for reducing self-harm and suicidal behavior in patients with borderline personality traits. 1 DBT was specifically developed for borderline personality disorder and combines elements of cognitive-behavioral therapy, skills training, and mindfulness techniques. 1

• DBT reduces nonsuicidal and suicidal self-directed violence by more than 50% in patients with borderline personality disorder and recent self-directed violence. 1
• Most effective DBT protocols involve structured sessions focusing on emotion regulation, interpersonal effectiveness, and distress tolerance. 1
• DBT is superior to treatment as usual for reducing self-harm behaviors in this population. 1

Crisis Response Planning

Implement a structured crisis response plan collaboratively with the patient, which has shown statistically significant reduction in suicide attempts compared to treatment as usual. 1 The plan should include:

• Collaborative identification of clear warning signs (behavioral, cognitive, affective, or physical triggers). 1
• Specific self-management skills the patient can use independently (grounding techniques, journaling, music—which she already uses). 1
• Identification of social support persons (her sister, mother, church community). 1
• Crisis resources including emergency contacts and suicide lifeline. 1

Medication Optimization Considerations

Current Fluoxetine Dosing

The patient is already on fluoxetine 60mg daily (3 caps of 20mg), which is at the upper end of the therapeutic range. 1 Continue this dose as SSRIs are first-line treatment for adolescent depression and have been shown to reduce suicidal ideation in depressed adults. 1, 3

However, maintain heightened vigilance during the early stages of any medication changes, systematically inquiring about suicidal ideation and watching for behavioral activation, akathisia, or increased agitation. 1, 3 If SSRI-induced akathisia develops with worsening suicidality, consider temporary dose reduction or addition of propranolol (which she already has available PRN). 1

Aripiprazole Continuation

Continue aripiprazole 400mg IM monthly as it provides mood stabilization and addresses any psychotic features. 4 The combination of aripiprazole with lithium is explicitly recommended by guidelines for bipolar disorder with depressive features. 4

Medications to Avoid

Benzodiazepines

Avoid prescribing benzodiazepines beyond very short-term crisis use (despite her current PRN propranolol being appropriate). 1, 2 Benzodiazepines may disinhibit some individuals, leading to increased aggression and suicide attempts, and they reduce self-control. 1, 2

Tricyclic Antidepressants

Never prescribe tricyclic antidepressants due to their high lethality in overdose—their fatal toxicity index is 5-8 times higher than SSRIs. 1, 3

Alternative Considerations if Lithium Cannot Be Used

Valproate

If lithium is contraindicated or not tolerated, consider valproate 125mg twice daily, titrating to therapeutic blood levels of 50-100 mcg/mL. 4, 5 Valproate has shown efficacy for affective dysregulation and impulsive-behavioral dyscontrol in borderline personality disorder. 5, 6

However, valproate carries additional concerns in adolescent females including:

• Risk of polycystic ovary disease. 4
• Teratogenicity requiring careful contraceptive counseling. 4
• Weight gain and metabolic effects. 4

Quetiapine Augmentation

Low-dose quetiapine 25-50mg at bedtime could be increased from her current PRN dosing to scheduled dosing for both sleep and mood stabilization. 7, 8 Quetiapine has shown preliminary efficacy in reducing self-mutilation and impulsive behavior in borderline personality disorder. 8

However, quetiapine carries significant metabolic risks including weight gain and diabetes risk, requiring baseline and ongoing monitoring of BMI, fasting glucose, and lipids. 4

Expected Timeline and Follow-Up

• Schedule weekly follow-up visits initially to assess medication response, suicidal ideation, adherence, and side effects. 1, 2
• Lithium's anti-suicide effects may begin within 2-4 weeks, but full therapeutic benefit requires 6-8 weeks at therapeutic levels. 1, 4
• DBT benefits typically emerge within 6-12 sessions when combined with pharmacotherapy. 4
• If suicidal ideation remains severe after 2 weeks of optimized treatment, consider psychiatric hospitalization rather than continuing outpatient management. 1

Critical Pitfalls to Avoid

• Never discontinue fluoxetine abruptly as this may precipitate withdrawal symptoms and worsening depression. 3
• Do not add antidepressants without ensuring adequate mood stabilization first, as this patient has features of both persistent depressive disorder and borderline personality traits. 1, 2
• Avoid medication polypharmacy without clear rationale—lithium augmentation of existing SSRI therapy has the strongest evidence base. 1, 2
• Do not underestimate the importance of psychosocial interventions—medication alone is insufficient for borderline personality traits, and DBT is the treatment of choice. 1, 7
• Never provide large quantities of any medication to patients with active suicidal ideation, regardless of the medication's safety profile. 1, 2, 3