Synonyms for Sick in the head:

• adj.

  •bananas (adjective)
  • out of one's mind,
  • nuts,
  • out to lunch,
  • kooky,
  • deranged,
  • disturbed,
  • psycho,
  • wacky,
  • cuckoo,
  • mad,
  • unsound,
  • sick,
  • crazy,
  • unhinged,
  • maniac,
  • lunatic.
  •brainsick (adjective)
  • crazed,
  • psychotic,
  • disordered.

• Other synonyms:

  •
  • crackers,
  • mentally ill,
  • fruity,
  • dotty,
  • bananas,
  • Daffy,
  • batty,
  • brainsick,
  • bonkers,
  • loco.
  •
  • demented,
  • nutty,
  • maniacal,
  • distraught,
  • unbalanced,
  • screwy,
  • buggy,
  • daft,
  • cracked,
  • non compos mentis.
  •
  • moonstruck,
  • touched.

Antonyms for Sick in the head:

• adj.

  • bananas
    healthy, sensible, sane.