Rob and Michele Reiner's son had long struggled with behavioral issues, but ultimately it's the choices he made that took him down this destructive path. That's what a new source is claiming. As we've been reporting, the 78-year-old filmmaker and his 68-year-old wife were found by their daughter, Romy Reiner, brutally slain in their Brentwood, Los Angeles home on Sunday afternoon. Rob and Michele's son Nick, 32, was arrested and booked on suspicion of murder hours later. Since the horrific news broke, we've learned more and more about what life was really like for the Reiner family over the years. Michele reportedly confided to pals for months that she and Rob were at their wits' end and unsure how to help him amid his years-long struggle with drug addiction. A source told Page Six that Nick also "really resented his dad" and "hated himself for not being as talented, prolific or beloved as his dad or grandad," Carl Reiner. Related: Trump Doubles Down With More Heinous Comments About Murdered Director Rob Reiner However, Rob and Michele's yoga teacher, who taught them for years in the early 2000s, told Page Six on Monday that their struggles with Nick allegedly began from a very early age. According to Alannaf Zabel, their son "interrupted pretty much all of [their] yoga sessions" at their home in Los Angeles. She claimed the disruptions lasted "20 minutes or so," adding to Dailymail.com that it was often "intense" and involved a lot of "screaming." Eventually, Rob and Michele decided to get help. Alanna, who has a degree in child development, told Page Six that "Rob and Michelle asked [her] to do yoga with Nicky privately" in the hopes that it would calm his nervous system. She agreed, saying that Nick was "this little boy" with "behavioral issues." He allegedly "was always upsetting everyone," but was "trying to figure it out." The yoga instructor continued: "Boys are wild in general, not just Nicky. And so I would always focus on the physicality: 'Let me teach him how to do a handstand, let me teach him how to do crow so he can feel this sense of accomplishment in his body.' I really focused our sessions on trying to exhaust him so that I could get to that place of connection and mindfulness." However, Alanna said she "rarely got there because he was just inexhaustible." She remembered Nick was unusually energetic and even wondered if he had attention-deficit/hyperactivity disorder since kids and teens with ADHD are more likely to abuse substances, per the Child Mind Institute. **It's important to note that many, many kids have ADHD and/or other disorders who go on to lead successful, productive lives. Clearly there were other things going on with Nick, specifically, drug use.** And as we mentioned, Nick struggled with drug addiction for most of his life. Alanna added: "That kind of energy requires a lot of disarming. But I know a lot of kids who were of that intensity who turned out to be well-adjusted adults." Yes, it's extremely important to reiterate that last part: "a lot of kids who were of that intensity who turned out to be well adjusted adults." The AZIAM Yoga founder noted there are many "variables" to consider with a child's behavior, including genetic and environmental components: "There's also the fact that [the Reiners live] in Hollywood. I have witnessed the children of Hollywood personalities have a really difficult time [because they are] living in a fantasy world. The parents are prioritizing many things, including them, but there's often a perception of negligence. Then living in a major city, where drugs are so accessible. You can use the name of someone, and it can lead kids down the wrong road if they don't have the right guidance." But if any of this sounds like victim blaming, Alanna also shared that Rob and Michele did absolutely everything they could to help Nick. She said they handled his problems "head-on," despite being "passionate" people with very demanding lives. So, Alanna feels that ultimately Nick "chose a negative perception" of his circumstances and took on "a personal neglect," claiming he had "an egocentric mindset": "I really think that he took on a lot of things that he didn't need to." Alanna later wrote a children's book, A Chair in the Air, inspired by Nick. Rob and Michele gave her their blessing but did not participate in the publication following a recommendation from their family's therapist. She went on to say: "I believe that there's an epidemic of life moving so fast that parents, teachers, principals, anyone in charge of children, they're moving so fast that they aren't giving proper attention. And children need attention in order to thrive and to feel whole and secure." Ultimately, in light of the tragedy, Alanna's "advice" to parents is to "make sure that you are present and grounded and giving proper attention." What a horrible situation. Our hearts really break for this family right now... If you or someone you know is experiencing substance abuse, hel