As a lineman for the Miami Dolphins, Jonathan Martin was at the center of a scandal in 2013 that created a national conversation around bullying and mental health in sports.

He left the N.F.L. two years later, and has contended with depression and anxiety. He’s bounced from job to job and was arrested in 2018 and charged with making a criminal threat for posting to social media a disturbing photo of a rifle. The charge was dismissed this year after Martin completed a diversion program.

In his first public interview in years, Martin, 32, said that therapy and medication have helped control his depression, anxiety and mood swings, a point he plans to underscore when he speaks Friday at a conference at Boston University focused on chronic traumatic encephalopathy, or C.T.E., a degenerative brain disease linked to repeated head hits.

Martin said he is working on a documentary about his turbulent N.F.L. career, but for now is focused more on his health. This week he pledged his brain to Concussion Legacy Foundation to further the science of C.T.E. He believes that his 13 years playing football contributed to his struggles, which began long before he was drafted in 2012 out of Stanford.

When did your troubles with mental health begin?

I definitely in retrospect struggled with mental health as far back as I can remember. I would say that playing in the N.F.L. and afterward was a marked shift, like much more severe depression, anxiety, social anxiety that I really hadn’t felt before, overwhelming panic attacks in work settings. It’s made it challenging to stay employed.

I know for a fact that I have at least a history of at least a moderate concussion. I never reported any concussions when I was playing. But you can see on an M.R.I. evidence from moderate concussions. So it’s hard to not at least think that there’s some causal effect between playing football for 13 years and an increase in depression.

Before joining the N.F.L., did you ever seek treatment?

There’s a taboo around depression, mental illness. It’s really been in the last year that you’ve had major athletes talk about mental health, like Naomi Osaka or Simone Biles. So I didn’t acknowledge those things. I wasn’t diagnosed with depression until maybe 24 when I was still in the N.F.L.

When I was playing, no one really talked about mental health. You play through so much as a player, you have this warrior mentality. You have to suffer so much physically, mentally and emotionally to play this game at a high level. When I was playing, there were not services readily available within the team. There is definitely a trust gap in the N.F.L. between players and medical staff. It’s just the nature of the game. So even if you know the therapist isn’t violating HIPAA, [] the team is aware that you are seeing them with some sort of regularity, does that affect your job status? Who knows?

The N.F.L. is doing a lot with the mental health and wellness campaign. And the resources for former players have increased with the new C.B.A. So there is at least an acknowledgment that this is a thing that current or former players struggle with. I’m glad the conversation shifted. I just wished it would have happened a little faster.

What happened after you left the N.F.L. in 2015?

I went back to school to get my degree. I spent the next several years interning at various places in real estate and finance. But it’s been really challenging to build and maintain relationships when you are dealing with a chronic issue like depression or potentially C.T.E. You tend to be more miserable, that can make it challenging. I would say in the past six years, that’s really been the biggest frustration for me, this inability to build a second career because I’ve tried.

Do you follow football?

I still enjoy the game. My relationship overall with football for me was a net positive. It got me into a great school, paid for my education, and I had an opportunity to play professionally, being a high draft pick and the benefits that go along with that. Then obviously there were some consequences and complications while I played. The way I look at it is I played football so hopefully my kids don’t have to.

What was your what was your reaction when you saw Naomi Osaka and Simone Biles?

It felt pretty powerful to see people at the top of their game and top of their sport making a stand, especially people of color.

I don’t think people fully realize, it’s still just a 22, 23, 24-year-old human being showing up to work and they just happen to be an athletic freak that’s great at what they do. And they have the same thoughts, feelings and emotions as every fan, that weighs on your psyche a lot. For example, giving up two sacks on “Monday Night Football” and when you’re 24 years old, that weighs heavily on your mental health.

Why do you believe you may have C.T.E.?

I don’t know that I have C.T.E., but I have my suspicions. I do know that I have traumatic brain injury.

I think more guys than people realize will admit in private to dealing some of the symptoms of C.T.E., but few will acknowledge it publicly, partly from the stigma and partly just because they don’t want to deal with the attention. But most guys when you’re playing, you’re kind of aware this is not very good for you. It’s probably not good for your brain.

From that experience of knowing I used my head a whole lot and then my understanding of C.T.E., the early stages are behavioral, not so much cognitively. I definitely have had some struggles behaviorally that were poor decisions, where I was like, “why the hell did I do that,” and thinking that it could be attributable to other things, years of playing football, tons of severe headaches.

I remember when I was 17, I went to a neurologist because I was having these migraines. They weren’t able to figure out what the problem was. But these migraines were extremely severe and I kept getting them into my freshman year, but I didn’t tell any of the coaching staff in college because I didn’t want people to think I was soft. I had migraines so bad I could barely see or speak during practice.