Brain-derived neurotrophic factor levels in first episode of psychosis: A systematic review

Table 1 Characteristics of the included studies

Ref.	Sample	Age (yr)	Matched for	Illness duration (yr)	Medication	BDNF measurement
Jockers-Scherübl et al[9]	157 FEP	31.8	Age, gender	Not reported	Drug naïve	Serum
	72 Ctl	32.3
Zakharyan et al[10]	25 FEP	25.3 ± 9.2	Age, gender	18.4 ± 7.2	Drug naïve	Plasma
	105 Ctl	37.3 ± 11.3
Murphy et al[11]	15 FEP	18.6 ± 3.3	Age, gender	Not reported	Quetiapine	Serum
	15 Ctl	18.5 ± 3.1
Sotiropoulou et al[12]	50 FEP	29.84 ± 8.20	Age, gender	Not reported	Drug naïve	Serum
	50 Ctl	31.36 ± 7.96
Ruiz de Azua et al[13]	47 FEP	24.3 ± 8.5	Age, gender, education level	Not reported	Drug naïve, Rsp, Olz	Plasma
	47 Ctl	24.0 ± 8.8
Yoshimura et al[14]	50 FEP	30.8 ± 5.3	Age, gender	Not reported	Apz	Plasma
	50 Ctl	32.3 ± 7.1
Rizos et al[5]	20 FEP	30.8 ± 10.5	Age, gender, education level, employment	Not reported	Drug naïve	Serum
	21 Ctl	34.0 ± 4.7
González-Pinto et al[15]	18 FEP	24.39 ± 6.53	Age, gender	Not reported	Drug naïve1	Plasma
	18 Ctl	25.19 ± 5.95
Rizos et al[16]	37 FEP	26.81 ± 9.22	Age, gender	Not reported	Drug naïve	Serum
	22 Ctl	26.59 ± 4.47
Jindal et al[17]	41 FEP	22.40 ± 5.47	Age, gender	Not reported	Drug naïve	Serum
	41 Ctl	22.31 ± 5.67
Goto et al[18]	18 FEP	29 ± 11	Age, gender	9.4 ± 6.8	Drug naïve, Rsp/Olz/Apz	Serum
	18 Ctl	30 ± 11
Pillai et al[19]	34 FEP	32.19 ± 8.74	Age, gender	Not reported	Drug naïve	Plasma
	36 Ctl	38.30 ± 1.26
Rizos et al[20]	31 FEP	26.81 ± 9.22	Age, gender, education level, employment	Not reported	Drug naïve	Serum
	22 Ctl	26.81 ± 9.22
Chen da et al[21]	88 FEP	29.2 ± 9.6	Age, gender, education level, smoking	23.4 ± 19.1	Drug naïve	Serum
	90 Ctl	29.8 ± 9.8
Rizos et al[22]	14 FEP	25.4 ± 5.8	Age, gender, education level, employment	Not reported	Drug naïve	Serum
	15 Ctl	26.6 ± 5.0
Buckley et al[23]	15 FEP	21.00 ± 8.83	Age, gender	25.2 ± 33.0	Drug naïve	Plasma
	14 Ctl	25.00 ± 5.72
Palomino et al[24]	48 FEP	23.7 ± 1.0	Age, gender	Not reported	Atypical, mood stabilizers	Plasma
	43 Ctl	25.5 ± 0.8
Pirildar et al[25]	22 FEP	27.81 ± 9.54	Age, gender	15.2 ± 13.0	Drug naïve1	Serum
	22 Ctl	25.7 ± 5.8

¹BDNF levels were also assessed after antipsychotic treatment (Olz, Rsp, Cloz) but not included in the review. Data are presented as mean ± SD. Apz: Aripiprazole; BDNF: Brain-derived neurotrophic factor; Cloz: Clozapine; Ctl: Controls; FEP: First episode psychosis; Olz: Olanzapine; Rsp: risperidone.