Can Invega Sustenna (paliperidone) cause a change in personality, confidence, and social interactions after treatment for psychosis?

Personality and Behavioral Changes with Invega Sustenna

Invega Sustenna (paliperidone) can cause significant changes in personality, confidence, and social functioning, particularly affecting emotional expression, motivation, and interpersonal engagement—these are recognized adverse effects of antipsychotic treatment that may represent medication-induced negative symptoms or emotional blunting.

Understanding What You're Experiencing

The symptoms you describe—loss of confidence, becoming shy and withdrawn, difficulty talking with people, and feeling like a "different person"—are consistent with several medication-related phenomena:

Medication-Induced Negative Symptoms

• Antipsychotics like paliperidone can cause or worsen negative symptoms including reduced emotional expression, decreased motivation, and social withdrawal 1
• These effects stem from dopamine D2 receptor blockade in brain regions that regulate emotion, motivation, and social behavior 2
• The extended-release formulation of paliperidone maintains continuous dopamine blockade, which may contribute to persistent personality changes 3, 2

Cognitive and Memory Effects

• Recent placebo-controlled evidence demonstrates that risperidone/paliperidone can worsen verbal learning and memory during early psychosis treatment, with medium to large effect sizes 4
• In a rigorous trial, patients receiving risperidone/paliperidone showed decline in immediate recall, verbal learning, and delayed recall, while placebo-treated patients improved 4
• These cognitive changes can manifest as difficulty with conversations, reduced mental sharpness, and altered sense of self 4

Emotional Blunting

• Antipsychotics commonly cause emotional flattening or restriction of emotional range, making patients feel less like themselves 1
• This can present as reduced ability to experience joy, decreased spontaneity, and dampened emotional responses in social situations 1

Critical Distinction: Medication Effects vs. Illness

A crucial pitfall is assuming all personality changes are due to the underlying psychosis rather than the medication itself. Your description suggests medication-related effects because:

• You had a clear baseline personality (happy, confident, dreamer) before treatment 4
• The changes occurred temporally after starting Invega Sustenna 4
• The symptoms you describe (shyness, fear, social difficulty) represent a departure from your pre-treatment state 1

What Should Happen Next

Immediate Assessment Required

Your prescriber must evaluate whether these changes represent:

• Secondary negative symptoms from medication (most likely given your description) 1
• Persistent positive symptoms causing withdrawal 1
• Depressive symptoms requiring separate treatment 1
• Sedation or extrapyramidal symptoms affecting function 5, 6

Treatment Modification Options

If medication-induced negative symptoms are confirmed, several evidence-based approaches exist:

1. Dose reduction while remaining in therapeutic range 1

   • Paliperidone may be effective at lower doses with fewer side effects 3, 2
   • Gradual reduction can improve negative symptoms without losing psychosis control 1

2. Switch to antipsychotic with better negative symptom profile 1

   • Cariprazine or aripiprazole are specifically recommended for predominant negative symptoms 1
   • Aripiprazole as a partial D2 agonist may restore some dopamine function while maintaining antipsychotic effect 1

3. Augmentation strategies if switching isn't appropriate 1

   • Low-dose amisulpride (50 mg twice daily) for negative symptoms 1
   • Antidepressant augmentation may provide modest benefit 1

Psychosocial Support Is Essential

• Psychosocial interventions should be offered to address psychological factors and encourage social engagement 1
• These interventions help distinguish medication effects from learned social withdrawal 1

Common Pitfalls to Avoid

• Do not accept "this is just your illness" without thorough evaluation of medication contribution 1, 4
• Do not continue unchanged treatment when quality of life is severely impacted 1
• Do not abruptly stop medication without medical supervision, as this risks psychosis relapse 7
• Do not assume these changes are permanent—many patients recover personality function with appropriate medication adjustment 1, 4

The Path Forward

You should request an urgent appointment with your prescriber to discuss these personality changes. Come prepared to describe:

• Your specific pre-treatment personality traits 4
• Timeline of when changes occurred relative to injections 4
• Impact on daily functioning, relationships, and quality of life 7
• Any other symptoms (sadness, stiffness, sedation) 1, 5

The goal is finding the lowest effective dose or most appropriate medication that controls psychosis while preserving your core personality and functioning 1. This is achievable for most patients with systematic evaluation and treatment adjustment 1, 7.