Related Clues:

• Have an effect
• Function
• Highly excited
• See 67-Across
• Bouncing off the walls
• Fanatical
• Lead-in for -aholic
• Do the job
• Have an effect (on)
• Out of control
• Hysterical
• Excessively enthusiastic
• Hyperactive
• In a tizzy
• See 61-Across