Marc J. Diener, PhD, Psychologist in Roslyn, New York, 11576

Marc J. Diener, PhD

Marc J.  Diener, PhD
Accepting new clients - Contact me!

Marc J. Diener, PhD

Professions: Psychotherapist
License Status: I'm a licensed professional.
Primary Credential: Psychologist - 017465
Verified Credentials
1-800-651-8085 ext. 34432
Accepting new clients - Contact me!
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Office 1
1025 Northern Blvd.
Suite 305
Roslyn, New York 11576
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  • Accessible Parking
Office 2
1800 Rockaway Ave.
Suite 206A
Hewlett, New York 11557
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  • Accessible Parking

Billing and Insurance

I am an in-network provider for:

  • Beacon
  • Crystal Run
  • Emblem
  • Empire Plan
  • ValueOptions

Weekend Availability
Evening Availability

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What's unique about my practice?

(1) You will be working with an expert in the mental health field. I have a PhD in clinical psychology and received advanced training during my postdoctoral fellowship. I also gained invaluable experience at some of the best training institutions, including Bellevue Hospital and St. Luke's-Roosevelt Hospital Center.

(2) My scholarship in personality assessment, psychotherapy research, and psychotherapy integration is internationally recognized.

(3) You will be working with someone intensely involved in the field at the highest level of academic rigor, since I have provided training for psychology doctoral students for almost ten years; since 2007, I have worked as a full-time psychology professor in clinical psychology doctoral programs that have been accredited by the American Psychological Association.

(4) You can select from a range of premium psychology services such as psychotherapy and psychological testing.

(5) I specialize in a number of areas and am able to provide effective treatment for addiction, relationship issues, anxiety, and depression. I also offer comprehensive diagnostic evaluations and personality assessments, as well as testing for attention-deficit/hyperactivity and learning disorders.

Email or Call Marc J. Diener, PhD at 1-800-651-8085 ext. 34432

Specific Issue(s) I'm Skilled at Helping With



*Relationship Difficulties

*Substance Use

My Role as a Therapist

I see my role as providing you with the support, understanding, and skills that you need in order to make the changes YOU want. I work together with you to determine your goals and the ways that I can help you reach those goals. I use a number of therapy approaches, which allows me to tailor our work to your specific needs.

Services I Provide

  • Clinical Supervision
  • Consultation
  • Individual Therapy & Counseling
  • Online Counseling / Phone Therapy
  • Psychological Evaluation

Ages I Work With

  • Teens
  • Adults
  • Elders


  • English

Client Concerns I Treat

  • Anxiety
  • Depression
  • Drug and Alcohol Addiction
  • Dual Diagnosis
  • Relationships and Marriage

Types of Therapy

  • Cognitive Behavioral Therapy (CBT)
  • Psychoanalysis / Modern Psychoanalysis
  • Psychodynamic

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