Table 1 Search strategy

1

neurological$.ab, kw, rt, tm, ti.

278114

2

(neuro$ adj3 sign#).ab, kw, rt, tm, ti.

22797

3

soft sign#.ab, kw, rt, tm, ti.

1109

4

(soft adj2 neuro$).ab, kw, rt, tm, ti.

1411

5

NSS.ab, kw, rt, tm, ti.

2494

6

SNS.ab, kw, rt, tm, ti.

4661

7

1 or 2 or 3 or 4 or 5 or 6

294985

8

exp schizophrenia/

244555

9

(schizo$ or psychotic$ or psychosis or psychoses or hebephreni$ or oligophreni$).ab, kw, rt, ti.

365517

10

((CHRONIC$ or SEVER$) adj5 MENTAL$ adj5 (ILL$ or DISORDER$)).ab, kw, rt, ti.

18088

11

first episode.ab, kw, rt, ti.

15961

12

Prodrom$.ab, kw, rt, ti.

9987

13

8 or 9 or 10 or 11 or 12

434722

14

7 and 13

8678