Marc J. Diener, PhD, Psychologist in Roslyn
You have a lot of choices in selecting a therapist and psychologist. What's different about me and my practice? (1) You're getting an expert: I have a PhD in Clinical Psychology, I completed advanced training in my postdoctoral fellowship, and I trained at prestigious institutions, including Bellevue Hospital and St. Luke's Roosevelt Hospital Center/University Hospital of Columbia University College of Physicians and Surgeons. (2) I am an internationally recognized scholar in psychotherapy research, personality assessment, and psychotherapy integration (synthesizing techniques and approaches from a number of widely used psychotherapy methods).
(3) I have trained the next generation of clinical psychologists for almost a decade: I have been a full-time psychology professor in American Psychological Association accredited clinical psychology doctoral programs since 2007. (4) I provide a variety of high-quality psychology services, including Psychotherapy and Psychological Testing.
(5) I have a number of specialty areas in my practice, including therapy for substance abuse, depression, anxiety, and relationship difficulties, as well as testing for Learning Disorders, ADHD, personality assessment, and comprehensive diagnostic evaluations. Please visit my website for more information:
Call or Email Marc J. Diener for a free phone consultation now - (646) 430-8717


  • Years in Practice: 10 Years
  • School: Adelphi University
  • Year Graduated: 2006
  • License No. and State: 017465 New York


  • Avg Cost (per session): $200 - $300
  • Sliding Scale: Yes
  • Accepts Insurance: Yes
  • Accepted Payment Methods: Cash, Check

Accepted Insurance Plans
  • Crystal Run Health Plan-Commercial
  • EmblemHealth
  • NY State Empire Plan
  • ValueOptions
  • Out of Network
Verify your health insurance coverage when you arrange your first visit.

Additional Credentials

  • Membership: American Psychological Association, Division 29/Awarded Fellow Status in 2015
  • Member Since: 2006
  • Membership: Society for Personality Assessment
  • Member Since: 2007


  • Depression
  • Relationship Issues
  • Addiction


  • ADHD
  • Anger Management
  • Anxiety
  • Behavioral Issues
  • Child or Adolescent
  • Coping Skills
  • Divorce
  • Drug Abuse
  • Dual Diagnosis
  • Emotional Disturbance
  • Family Conflict
  • Grief
  • Intellectual Disability
  • Learning Disabilities
  • Parenting
  • Peer Relationships
  • Self Esteem
  • Sexual Abuse
  • Spirituality
  • Substance Abuse
  • Testing and Evaluation
  • Trauma and PTSD

Mental Health

  • Mood Disorders

Client Focus


  • Adolescents / Teenagers (14 to 19)
  • Adults

Treatment Approach

Treatment Orientation

  • Cognitive Behavioral (CBT)
  • Integrative
  • Motivational Interviewing
  • Psychoanalytic
  • Psychodynamic
  • Psychological Testing and Evaluation


  • Individuals
Last Modified: 27 Jul 2017
Marc J. Diener, PhD, Psychologist in Roslyn

Marc J. Diener

Psychologist, PhD