Marc J. Diener, PhD, Licensed Clinical Psychologist

I am Dr. Marc J. Diener, a New York State Licensed Psychologist dedicated to providing comprehensive mental wellness services in Cedarhurst, New York. My practice encompasses individual therapy, psychological testing, and consultations across various psychological fields. As a Full Professor within the Clinical Psychology Doctoral Program at Long Island University-Post, my passion extends beyond clinical practice to mentoring and guiding future generations of psychologists. I oversee the clinical work of doctoral students, sharing my expertise and fostering their growth in the field.

My journey in psychology began with a private practice in the Washington, DC area before establishing my current presence in Hewlett, Roslyn, and Great Neck. My academic career includes serving as an Assistant Professor in the Clinical Psychology Doctoral Program at the American School of Professional Psychology in Washington, DC. I hold my PhD from the esteemed Derner Institute of Advanced Psychological Studies at Adelphi University, a program renowned for its rigorous training in clinical psychology.

My clinical training encompassed diverse and impactful experiences. My doctoral externship at Bellevue Hospital offered valuable exposure to complex patient populations and critical care settings. Substantively, my internship and postdoctoral fellowship at St. Luke's Roosevelt Hospital Center, affiliated with Columbia University College of Physicians and Surgeons, provided a comprehensive foundation in providing psychological services within a university hospital setting.

Clinical Services

Through my individual therapy practice, I strive to provide a safe and supportive space for individuals grappling with a wide range of challenges. My therapeutic approach is tailored to each individual's unique needs and goals, encompassing areas such as:

• Depression: Utilizing evidence-based therapies, I work with individuals to understand and manage symptoms of depression, fostering resilience and emotional well-being.
• Anxiety: I offer various therapeutic strategies to help clients cope with and overcome anxiety disorders, including generalized anxiety, social anxiety, and panic disorder.

• Relationship Difficulties: I provide couples and family counseling to address communication issues, conflict resolution, and fostering healthier relationship dynamics.
• Substance Use: I specialize in assisting individuals struggling with substance abuse, providing personalized treatment plans that incorporate therapy, support groups, and relapse prevention strategies.

Psychological Testing

I offer comprehensive psychological testing to assess a variety of cognitive, emotional, and behavioral concerns. These assessments provide valuable insights into an individual's strengths, challenges, and potential areas for growth. My areas of expertise in psychological testing include:

• Learning Disorders: I conduct thorough assessments to identify potential learning disabilities, such as dyslexia or ADHD, enabling appropriate interventions and educational support.
• Attention-Deficit/Hyperactivity Disorders (ADHD): I provide comprehensive evaluations to diagnose ADHD and develop individualized treatment plans, ensuring access to appropriate support and strategies.
• Diagnostic Clarification: I conduct assessments to clarify diagnoses and guide treatment decisions for individuals experiencing complex emotional or behavioral difficulties.
• Emotional and Behavioral Concerns: I utilize psychological testing to gain a deeper understanding of an individual's emotional functioning, behaviors, and coping mechanisms.

Research and Consultation

Beyond my clinical practice, I serve as a Consultant in statistics, research methods, and writing. I assist researchers and professionals in designing and executing rigorous research studies, analyzing data effectively, and disseminating their findings through clear and concise writing.