Chad, 34, has had many privileges, such as being a professional cyclist and training with athletes like Lance Armstrong. However, Chad's deviant behavior and his turn to drugs like crack caused his cycling career and reputation to be questioned. His family are holding an intervention in hoping Chad's "rock bottom" won't end up being his own death

Emily is an excessive dieter. At 26, she has already had a difficult life battling depression with low self-esteem and negative thoughts. Emily was a date-rape victim in college and used dieting as a means of controlling her emotions. However, she now weighs less than 90 pounds and is on a slippery path that could easily end in death. Emily's family is hoping an intervention will save her.

This follow-up looks at two addicts from Season 3. First was Ryan, the very troubled OxyContin addict we saw in the premiere. Recall that he left treatment early and there weren't very many good updates on his progress. How is Ryan doing now? Hubert is an alcoholic who confronted his feelings during his intervention. What is Hubert doing now in his sobriety?

Brooke, 26, uses prescription pain killers to control her early onset of rheumatoid arthritis. Brooke has now become addicted to these prescription pills, which often contain opiates, a very addictive category of substances. She denies her dependence on the drug and her family is hoping an intervention can make her realize that she needs help.

Jason, 23, is from a religiously strict family. Jason's parents dealt plenty of punishments. However, after his mother reveals a pressing secret, Jason's father was ejected from the church and had to take up several jobs to feed his family. Left with minimal supervision, Jason turned to drugs and alcohol, and his younger sister, Joy, soon followed. Can a double intervention save these siblings?

Ben is a 25-year-old potential genius but has a past filled with violence, homelessness, and isolation. Ben dealt with his troubles by turning to a drug called DXM. DXM is found in some cough-suppressants that, when taken at higher doses, produces effects similar to PCP (a hallucinogenic). Ben performs desperate crimes to finance his addiction. Josh is a 22-year-old food addict who weights 550lbs. Josh's father has the same weight problem with diabetes and a history of 6 strokes at 317lbs. Josh's father does not want an early death for his son, and the whole family hopes that both Josh and Rex can support each other through an intervention to get healthy.

Tressa is 32 and was one of the world's top female shot-putters. However, a routine drug test revealed a life as a IV drug user. Tressa is now using crystal meth daily as her life spirals out of control. Can her family save Tressa?

John was a former athletic star but an injury led him to drown his disappointment in alcohol and a variety of drugs. John is aggressive and his addiction is fueling distance between everyone he knows. Many family members are participating in hopes that an intervention can save John's life.

After serving two rounds in Iraq, Brad has returned home but has brought some extra baggage with him: post-traumatic stress disorder (PTSD). He has begun to use drugs and alcohol to numb and forget the endless nightmares and flashbacks that haunt him. Unfortunately, it is getting worse, and his temper and reckless behavior are becoming life-threatening to himself and others. His family is banding together and holding an intervention.

Lawrence, 34, is a successful entrepreneur but had a dark past of emotional and physical abuse. He numbs his pain with alcohol, drinking litres of alcohol a day. He has also battled cancer recently. His family gather for an intervention in the hope to change his life.

Marie struggled with poverty and has had 3 marriages end in divorce. She still managed to become successful, becoming a matchmaker and socialite, appearing on TV and other talk shows. Her next husband is an addict and an alcoholic and Marie soon had the same problem - alcohol. Marie's family is racing to hold this intervention in hope that she will change her ways.

Tom grew up in a gangster lifestyle in a rough Boston neighborhood. By the time he was 20, he was working as a fireman but dealing drugs and getting into trouble by night. Tom has a family and four children but has now lost them all due to the pending drug charges after being caught. Can his family save him from losing everything?