concetration

Interesting. I looked up ADD symptoms, and I think they largely overlap INTP traits:

• Easily distracted; forgetful; daydreaming
• Procrastination; inability to complete things
• Disorganization; messiness; clutter
• Difficulty with making decisions
• Behavioral or verbal impulsiveness
• Difficulty with expressing thoughts in speech or in writing
• Significant periods of depression; low self-esteem
• A sense of failure; not living up to one's potential
• A sense of being different, unconventional
• A sense of internal restlessness; constantly active
• Difficulty with falling asleep or waking up alert
• Very sensitive to being told to do something, teasing, criticism, rejection or anger
• A sense that your mind is always active; thoughts jumping - from one topic to the next
• Easily bored; intense need for excitement
• Difficulty with following rules
• Very impatient; low frustration tolerance
• Emotionally sensitive; easily upset, depressed, hurt or angered
• Difficulty with personal or work relationships
• Frequently late or rushed
• Difficulty in estimating how much time something will take
• Impulsive spending and money management problems
• Personal or family history of substance abuse, depression or anxiety
• Difficulty with reading comprehension or retention
• Frequently changing jobs, interests or activities
• Frequently losing or misplacing things
• Perfectionistic tendencies
• Strong need to control or have things your way

I experience 20-22 of the 27 symptoms listed.