Larry Birkhead is scheduled to resume testimony Monday in Los Angeles. He told jurors last week that Smith suffered from seizures and other ailments. Birkhead also testified that he thinks Smith exhibited loopy behavior during a 2004 awards show appearance and he believes drugs were partly to blame.
Smith's boyfriend, Howard K. Stern, and two doctors have pleaded not guilty to conspiring to provide the former Playboy model with massive doses of opiates and sedatives.
They aren't accused of causing her 2007 overdose death.