Johnny Lewis during the 36th Toronto International Film Festival on Sept. 14, 2011 (AP file)
(CBS News) -- Johnny Lewis, the "Sons of Anarchy" actor who allegedly killed his landlady before falling to his death, may have been having mental health problems and using drugs.
Sources tell the Los Angeles Times that detectives believe Lewis may have been on a synthetic drug known as 2C-I or "smiles" at the time of his death, according to CBS News Crimesider.
Lewis' cause of death is pending toxicology results, the city's Coroner said Thursday evening. Davis died from blunt head trauma and manual strangulation, he said.
"Smiles," or 2C-1, are part of a class of drugs known as phenethylamines. Drugs in the 2C family are "basically just amphetamines," Dr. Lewis S. Nelson, professor of emergency medicine in the division of medical toxicology at NYU Langone School of Medicine in New York City, explained to CBSNews.com.
According to Nelson, the amphetamine molecule contains a ring and a side chain. In the case of methamphetamine or crystal meth for example, amphetamine contains a "methyl" side chain. With 2C compounds, chemists make different substitutions on the rings and add a halogen (think back to a chemistry class periodic table: compounds like chlorine, fluorine, etc.), in this case Iodine.
By making these chemical changes, the amphetamine compound gains different effects. While typical amphetamine would cause a "speedy" feeling of high blood pressure, increased heart rate and sweating, the substitutions that make 2C-I create an amphetamine with more euphoric, psychedelic and introspective effects.
MDMA or Ectsasy is made similarly, by adding methylenedioxy to an amphetamine backbone.
"Chemically, they are all very similar drugs," Nelson said. "But by adding the different groups, you change drug's property."
The National Institute on Drug Abuse says 2C drugs have been on the illicit drug market since 1998. Because they are amphetamine-based, they are "Schedule I" controlled substances, considered illegal.
LiveScience reports "smiles" are often mixed with a substance like chocolate before eating. Side effects include auditory and visual hallucinations, and feelings of giddiness and empathy.
The problem, said Nelson, is whoever is making these drugs in an illegal lab has no means of quality control, and the drugs could contain different dosages and properties that cause potentially dangerous side effects. It can contain the expected drug, a different drug or no drug at all, he said.
He likens the process of how "smiles" are made to that of another designer drug, "bath salts," which have an amphetamine-like compound but may contain unknown chemicals.
"Substituted amphetamine can produce adverse effects such as heart attacks and strokes, even at low doses," Nelson said. "You ideally want to have a clean, safe high, but often you get very confused, altered and your decision-making is flawed."
LiveScience reports "smiles" were implicated in the deaths of two teenagers from East Grand Forks, North Dakota. One 18-year-old was found dead and then the following day, a 17-year-old took 2C-I and began hyperventiliating, hitting his head against the ground and stopped breathing several hours later. Following the deaths, police in the area warned about a possibly tainted batch.