Table 2.
Comparison of Mean Change (6th Week - Baseline) of Positive and Negative Symptom Scale (PANSS) Scores in Patients with Schizophrenia Receiving Melatonin or Placebo
| Variables |
Mean change (T3 – T1)
for intervention group (n = 23) |
Mean change
(T3 – T1) for placebo group (n = 23) |
Mean
difference |
P-value
(t-statistic) |
Cohen’s D |
|---|---|---|---|---|---|
| Negative symptoms | -7.09 ± 4.03 | -3.39 ± 6.97 | 3.70 | 0.032 (2.204)* | 0.65 |
| Positive symptoms | -11.56 ± 6.09 | -10.00 ± 6.24 | 1.56 | 0.395 (0.858) | 0.25 |
| General psychopathology | -15.00 ± 7.92 | -12.35 ± 8.83 | 2.65 | 0.289 (1.071) | 0.31 |
| PANSS total score | -33.65 ± 13.63 | -25.74 ± 21.60 | 7.91 | 0.144 (1.485) | 0.43 |
T1 = before intervention at baseline, T3 = six weeks after beginning the intervention.