Book a therapist or psychiatrist in Flagstaff, AZ covered by United Healthcare

If anxiety, depression, ADHD, or life's challenges have left you feeling stuck, overwhelmed, or unlike yourself, you don't have to figure it out alone. I'm Mark Lindsay, a Psychiatric Mental Health Nurse Practitioner and Family Nurse Practitioner who believes mental health care should be approachable, practical, and centered around you. By combining my medical and psychiatric experience, I look beyond symptoms to understand the full picture, helping you find real solutions that restore confidence, improve daily life, and move you toward lasting wellness.

My priority is to provide a safe, compassionate, and non-judgmental space where you feel heard, respected, and supported. With over 40 years in healthcare—including service as a former Navy Nurse Corps Officer and retired military veteran—I bring values of resilience, trust, and teamwork into every therapeutic relationship. I view care as a partnership and work to empower you to take an active role in your mental health.

Clinical Focus & Services

I provide pharmacotherapy (medication management) motivational interviewing, and other therapeutic modalities. We can assess during the first meeting if your treatment requires additional therapeutic support. I will provide a referral to a licensed therapist to ensure you receive comprehensive care. My practice supports:

• ADHD (I am an ADHD Certified Clinical Support Provider)
• College students with focus/concentration concerns,school overload, or interrelationship difficulties
• OCD
• Anxiety & Stress
• Panic Disorder
• Social Anxiety Disorder
• Trauma
• Mild to Moderate Depression
• Interrelationship issues
• Smoking cessation
• Gambling addiction
• Shop lifting addiction
• Smoking Cessation
• Alcohol Addiction

My clients are the “overthinkers” in the world...with big feelings that are hard to explain. They feel misunderstood, lonely and isolated while striving to please others at the expense of themselves. They’re exhausted, overworked, and over-stressed, feeling like they’re never enough. They have a vision for life, but aren’t sure how to bring it together, especially after a life-changing event. They're also eager for change.

Does this sound like you? If so, I warmly welcome you to my practice.

Dr. MacKenzie ia board certified Adult and Child psychiatric NP and trained therapist Graduated Cum Laud from Case Western Reserve University in 2012 practicing in Texas, Oregon and most recently in Arizona since 2013. Prior to this he spent 10+ years as a Psychiatric and Critical Care RN in the community and a prior 10+ years in the US Army; where he learned a lot about anxiety, depression, grief and trauma. "I lived it, and with help I recovered. Then I studied what I myself have gone through to help others".

"If you think about it, there is no actual health without good mental health, and I work to help my clients achieve both."

Using the tools of Psychology as well as Psychiatric medication management (if appropriate), you can feel much better, function much better at home, work, and when you find yourself in those uncomfortable times.

Almost every symptom or unwanted trait can improve and in many cases, resolve completely, but only if you give it a chance.

I am a dual board-certified nurse practitioner. I graduated with my Family NP at Grand Canyon University in 2018.I graduated with my post-graduate cert as a Psychiatric Mental Nurse Practitioner at Wilkes University in 2022.I am constantly looking forward to continue my education to better serve my patients and to ensure that I am up-to-date with the latest advances in the fields of medicine and psychiatry.You will be treated with holistic care that combines traditional and alternative medicine.

My practice is able to see clients for most mental health diagnoses, utilizing most modalities. I specialize in the treatment of addictions and trauma and my experience in these areas is vast. I most enjoy utilizing IFS, EMDR, and AEPD to address these issues. I am EMDRIA certified in EMDR and IFS level I trained.