Investigations of the causes of ADHD have found that ...

[lbcchick]

Investigations of the causes of ADHD have found that environmental toxins, such as food additives and lead:
 
  a) Do not explain more than a small percentage of cases.
  b) Are usually the cause of the disorder in those children with an organic basis to their ADHD.
  c) Are more likely to cause attentional problems without hyperactivity, but not in those children with both attentional problems and hyperactivity.
  d) Cause subtle attentional problems, but not to the degree of ADHD.

Question 2

The personality disorders in the odd/eccentric cluster have been genetically linked to
 
  a) bipolar disorder.
  b) major depression.
  c) schizophrenia.
  d) dissociative identity disorder.

[matt95]

Answer to Question 1

a

Answer to Question 2

c

[lbcchick]

Thanks for the timely response, appreciate it

[covalentbond]

Excellent