Just a small sample of the destruction it does :

Psychiatric Disturbances:

Antisocial behavior, social deficit, social withdrawal: Mercury
Repetitive, stereotyped behaviors; OCD-typical behaviors: Mercury
Depression, mood swings, flat affect; impaired facial recognition: Arsenic, Copper, Lead, Mercury
Pervasive Developmental Disorder: Mercury, Lead
Schizoid tendencies; hallucinations; delirium: Mercury
Irritability, aggressive behaviors, temper tantrums: Lead, Mercury
Suicidal Behaviors: Copper, Mercury
Sleep difficulties / disturbances: Lead, Mercury, Thallium
Chronic fatigue (CFS); weakness, malaise: Aluminum, Arsenic, Cadmium, Copper, Lead, Mercury, Thallium
Anorexia; symptoms reflecting eating disorders, loss of appetite/weight:
Arsenic, Lead, Mercury
Anxiety; nervous tendencies: Thallium
Attention problems (ADHD), lacks eye contact, impaired visual fixation: Lead, Mercury
Speech and Language Deficits:

Speech disorders: Aluminum, Mercury
Loss of speech, developmental problems with language: Mercury
Speech comprehension deficits: Mercury
Dysarthria; articulation problems; slurred speech, unintelligible speech: Mercury
Cognitive Impairments:

Mental retardation, borderline intelligence: Arsenic, Lead, Mercury
Uneven performance on IQ scores, low IQ scores: Copper, Lead
Poor concentration, attention deficits (ADHD, response inhibition: Aluminum, Lead
Poor memory (short term, verbal, and auditory): Aluminum, Lead
Difficulties understanding abstract ideas; difficulty carrying out complex commands:
X metals
Dementia; pre-senile and senile dementia: Aluminum
Stupor: Aluminum, Arsenic
Impaired reaction time; lower performance on timed tests: Lead