An adverse event (AE) is defined as any untoward medical occurrence in a participant or clinical investigation participant administered a pharmaceutical product which does not necessarily have a causal relationship with the treatment. The investigator assesses the relationship of each event to the use of study drug.

Number of participants with abnormal change in clinical laboratory test results like hematology will be assessed.

Magnetic resonance imaging (MRI) of several different brain regions was per-formed, and volumetric analysis was con-ducted to quantify midbrain atrophy. Negative changes in values indicate a re-duction in volume.

Number of participants with abnormal change from baseline in vital sign measurements like systolic and diastolic blood pressure will be assessed.

12-lead resting ECGs will be recorded. Parameters include heart rate, PR interval, QT interval, QRS duration, and QT interval corrected using Fridericia's formula (QTcF).

The C-SSRS is a clinician-rated instrument that reports the severity of both suicidal ideation and behavior, with a higher score denoting more severe suicidal ideation and behavior.

Measured by amyloid positron emission tomography (PET)

Cmax of ABBV-1758

Tmax of ABBV-1758

Ctrough of ABBV-1758

AUCtau of ABBV-1758

Cav,ss of ABBV-1758

AUCtau of ABBV-1758

CL of ABBV-1758

CL/F of ABBV-1758

Vss of ABBV-1758

Vz of ABBV-1758

β of ABBV-1758

Terminal phase elimination half-life of ABBV-1758

T1/2,eff of ABBV-1758