"I don't think anybody understood that [PTSD] was a real injury that, if untreated, would kill him," Patrick Kennedy tells PEOPLE of his late cousin David

By Tierney McAfee
Updated October 07, 2015 09:40 AM
Credit: Russell Turiak/Getty

The many tragedies suffered by one of America’s most famous families have long been attributed to the “Kennedy Curse” – but former Rhode Island Rep. Patrick J. Kennedy tells PEOPLE he believes mental illness was responsible for at least two of the darker chapters in Kennedy history.

Patrick explores his family’s struggles with mental illness and addiction in his controversial new memoir, A Common Struggle: A Personal Journey Through the Past and Future of Mental Illness and Addiction, as well as in PEOPLE’s latest issue, in which he explains how better diagnosis and treatment might have spared two of his relatives.

First there’s the heartbreaking story of his Aunt Rosemary, President John F. Kennedy’s sister who was left permanently incapacitated by a disastrous lobotomy and then hidden away from public view – and from her eight siblings – for decades in a facility for the mentally disabled.

Rosemary was born intellectually disabled, but Patrick suspects that she also suffered from mental illness, which, if recognized and properly treated, could have spared her the devastating lobotomy his grandfather Joseph P. Kennedy ordered to control his aunt’s outbursts. “She could have lived a life very free of disability,” Patrick laments to PEOPLE.

Then there was the untimely death of his cousin, Robert F. Kennedy’s son David, who fatally overdosed at 28 – a tragedy Patrick now believes was related to untreated PTSD.

“David lost his father so violently and then, having to watch it all on television,” Patrick says of his uncle RFK’s assassination. “I don’t think anybody understood that [PTSD] was a real injury that, if untreated, would kill him.”

The Untold Story of JFK’s Sister, Rosemary Kennedy, and the Disastrous Lobotomy Ordered by Her Father

The mental health activist and former Congressman, 48, who also details his own struggles with drug addiction, alcoholism and bipolar disorder in his new book, has been met with disappointment from his family. His brother, Ted Kennedy Jr., said he is “heartbroken” by the “inaccurate and unfair portrayal of our family” and his mother, Joan, has denied working on the project with Patrick.

Despite “breaking the family code” by publishing the memoir, he has no regrets. “The older I get, the more I see secrecy as the enemy within,” he tells PEOPLE.

“We still have a ways to go, both in society and within my own family,” he adds.

For much more of Patrick’s exclusive interview, pick up this week’s issue of PEOPLE, on newsstands Friday

Reporting by LIZ MCNEIL