What is the most likely diagnosis and appropriate management for a 28-year-old woman with intense mood swings that start one week before menses, have worsened over the past two months, and are now accompanied by passive suicidal ideation?

Premenstrual Dysphoric Disorder (PMDD) with Passive Suicidal Ideation

This 28-year-old woman most likely has Premenstrual Dysphoric Disorder (PMDD), and given the presence of passive suicidal ideation, she requires immediate safety assessment, initiation of an SSRI, and close monitoring with mental health referral.

Most Likely Diagnosis: PMDD

The clinical presentation strongly suggests PMDD based on:

• Cyclical timing: Intense mood swings beginning one week before menses (luteal phase) that resolve shortly after menstruation onset is the hallmark of PMDD 1
• Recent worsening: The 2-month escalation with emergence of passive suicidal ideation indicates severe disease 2
• Age and demographics: PMDD afflicts approximately 5% of women of fertile age, making this diagnosis highly relevant for a 28-year-old 1

Critical distinction: PMDD is neither a variant of depression nor an anxiety disorder, but a distinct diagnostic entity where irritability and affect lability are the most characteristic features, rather than depressed mood alone 1. However, the presence of suicidal ideation elevates this to a psychiatric emergency requiring immediate intervention.

Immediate Safety Assessment (Priority #1)

The American Psychiatric Association defines passive suicidal ideation as thoughts of death or wishing to be dead without an active plan or intent to kill oneself 3. However, passive suicidal statements should never be dismissed as unimportant, as they may represent the only way a patient can ask for help 3.

Required immediate assessment:

• Document specific suicidal thoughts: Ask directly about death wishes, specific plans, intent, and any preparatory behaviors 4
• Assess access to lethal means: Firearms, medications, sharp objects must be identified and restricted immediately 5
• Evaluate motivating feelings: Wish to escape intolerable situation, hopelessness, or desire to effect change in relationships 4
• Screen for psychiatric comorbidities: Depression, anxiety, bipolar disorder, and substance abuse commonly co-occur with suicidal behavior 4

Hospitalization criteria:

Hospitalize if the patient persists in expressing desire to die, remains agitated or hopeless, cannot participate in safety planning, lacks adequate support, or has history of high-lethality attempts 5.

Risk Stratification for This Patient

Women with PMDD who endorse premenstrual suicidal ideation represent a high-risk subgroup:

• 27% of women with premenstrual symptoms report concurrent new or worsening suicidal ideation 2
• Suicidal thoughts, ideation, plans and attempts are strongly associated with PMDD independent of psychiatric comorbidities 6
• Risk factors in this population: Being single, unemployed, childless, history of psychiatric hospitalization, adverse childhood events, and current depression 2

The 2-month worsening suggests either progression of PMDD severity or emergence of comorbid major depressive disorder, which must be differentiated 7.

Pharmacological Management

Initiate an SSRI immediately - this is the first-line treatment for PMDD and has demonstrated efficacy with rapid onset of action 1, 8:

• SSRIs are the treatment of choice for PMDD and show a shorter onset of action (often within days to weeks) compared to their antidepressant effects 1
• Select based on adverse effect profile: Fluoxetine, sertraline, or paroxetine are all effective; avoid paroxetine if sexual dysfunction is a concern 8
• Dosing options: Can be given continuously or only during the luteal phase (14 days before expected menses) 1
• Monitor for worsening suicidality: SSRIs increase suicide attempts in patients under age 25, requiring weekly monitoring within 1-2 weeks of initiation 8

Important caveat: If bipolar disorder is suspected (family history of bipolar disorder was present in 22.9% of women with severe PMS in one study 9), lithium should be considered as it reduces suicide attempts 8.6-fold and is effective in decreasing impulsivity 5.

Psychotherapeutic Interventions

Cognitive behavioral therapy focused on suicide prevention demonstrates the strongest evidence for reducing suicide attempts and suicidal ideation 8, 5:

• Immediate mental health referral is mandatory given the presence of suicidal ideation 4
• CBT reduces suicidal ideation, behavior, and hopelessness when added to pharmacotherapy 8
• Begin within 1-2 weeks of pharmacological initiation 8

Safety Planning and Monitoring

Develop a comprehensive safety plan immediately:

• Restrict access to lethal means: Remove firearms, lock medications, secure knives, and involve family members 5
• Identify warning signs: Specific premenstrual symptoms that precede worsening mood 5
• Establish concrete coping strategies: Distraction techniques, social supports, crisis hotline numbers 5
• Weekly monitoring for the first month: Assess for worsening suicidality, medication adherence, and treatment response 8

Differential Diagnosis Considerations

While PMDD is most likely, evaluate for:

• Major depressive disorder with premenstrual exacerbation: If depressive symptoms persist throughout the cycle, this is MDD rather than pure PMDD 7
• Bipolar disorder: Rapid mood shifts, irritability, and family history of bipolar disorder should raise suspicion 4, 9
• Borderline personality disorder: Unstable mood, unstable relationships, impulsivity, and recurrent suicidal behavior are features that overlap with both PMDD and BPD 4

Diagnostic approach: Have the patient prospectively track symptoms for 2 menstrual cycles using a daily symptom diary to confirm luteal-phase-only symptoms characteristic of PMDD 1.

Treatment Duration and Follow-Up

• Continue SSRI for at least 4-9 months after achieving satisfactory response 8
• If symptoms recur with discontinuation, consider long-term maintenance therapy 8
• Implement caring communications: Brief, supportive text messages or calls at regular intervals reduce suicide attempts by 43% 8, 5
• Monitor during luteal phase: The premenstrual phase represents a period of increased vulnerability for severe depression or worsening of ongoing depression 7

Critical Pitfalls to Avoid

• Never dismiss passive suicidal ideation as attention-seeking: This may be the only way the patient can ask for help 3
• Do not prescribe benzodiazepines: These reduce self-control in suicidal patients with impulsivity 5
• Do not delay mental health referral: Recognition of suicidal ideation should trigger immediate referral to a mental health provider skilled in addressing this condition 4
• Do not underestimate impulsivity: Many suicide attempts occur within minutes of the decision 5
• Ensure adequate SSRI trial duration of 6-8 weeks before switching medications, as inadequate trial duration is a modifiable risk factor for persistent suicidality 8, 5