Table 1 Search strategy for retrieval of relevant articles from multiple databases

MEDLINE (n = 106)

1. exp Suicide/

2. suicid*.mp.

3. exp Self-Injurious Behavior/

4. (self harm* or self inflict* or self injur* or self wound* or self mutilat*).mp.

5. automutilat*.mp

6. 1 or 2 or 3 or 4 or 5

7. brain derived neurotrophic factor.mp. or Brain-Derived Neurotrophic Factor/

8. bdnf.mp

9. 7 or 8

10. 6 and 9

EMBASE (n = 366)

1. exp suicidal behaviour/

2. suicid*.mp.

3. exp automutilation/

4. (self harm* or self inflict* or self wound* or self mutilat* or autmutilat*).mp.

5. 1 or 2 or 3 or 4

6. brain derived neurotrophic factor.mp. or exp brain derived neurotrophic factor/

7. bdnf.mp.

8. 6 or 7

9. 5 and 8

PsycINFO (n = 76)

1. exp Suicide/

2. exp Attempted Suicide/

3. exp Suicidal Ideation/

4. suicide*.mp

5. exp Self Injurious Behavior/

6. (self harm* self injur* or self inflict* or self wound* or self mutilat* or autmutilat*).mp.

7. 1 or 2 or 3 or 4 or 5 or 6

8. brain derived neurotrophic factor.mp. or exp Brain Derived Neurotrophic Factor/

9. bdnf.mp.

10. 8 or 9

11. 7 and 10

CINAHL (n = 4)

1. MH (“Suicide+”)

2. “suicid*”

3. MH (“Self-Injurious Behavior”)

4. “self harm*” OR “self injur*” OR “self inflict*” OR “self wound*” OR “self mutilat*” OR “automutil*”

5. 1 or 2 or 3 or 4

6. “brain derived neurotrophic factor”

7. “bdnf”

8. 6 or 7

9. 5 and 8