Table 3. Associations between PRSs for SCZ with cognitive, clinical and trait-related features of MDD in cases/controls separately.

Generation Scotland: SFHS
	Controls (n=16 764)			MDD cases (n=2587)
	β	P-value	R2	β	P-value	R2
Cognitive
Composite 'g' factor	−0.0773	2.61 × 10−17	0.3470	−0.0906	6.50 × 10−5	0.6671
Logical memory	−0.0600	2.33 × 10−13	0.3119	−0.0764	3.00 × 10−5	0.8353
Digit symbol	−0.0654	3.27 × 10−20	0.3258	−0.0906	7.35 × 10−8	1.0900
Mill Hill vocabulary	−0.0251	1.36 × 10−3	0.0379	−0.0131	5.01 × 10−1	0.0173
Verbal fluency	−0.0152	6.70 × 10−2	0.0190	−0.0064	7.54 × 10−1	0.0110
Clinical and trait-related features
Psycholog distress (GHQ)	0.0400	1.46 × 10−8	0.1487	0.0111	6.99 × 10−1	0.0149
Neuroticism	0.0369	91.15 × 10−6	0.1661	−0.0002	9.91 × 10−1	0.0009

UK Biobank
	Controls (n=27 476)			MDD cases (n=6049)
	β; z ratio	P-value	R2	β; z ratio	P-value	R2
Cognitive
Composite 'g' factor	−0.1203	6.99 × 10−13	0.3156	−0.1696	4.12 × 10−9	0.6162
Memory	0.0657	1.66 × 10−10	0.1536	0.0490	2.56 × 10−2	0.0863
Symbol digit substitution	−0.1006	2.79 × 10−7	0.2816	−0.0785	5.00 × 10−2	0.1802
Reaction time	0.0390	4.79 × 10−4	0.0422	0.0509	3.68 × 10−2	0.0692
Verbal-numerical reasoning	−0.1101	2.16 × 10−21	0.3467	−0.1390	2.88 × 10−8	0.5495
Clinical and trait-related features
PHQ	0.0827	3.25 × 10−14	0.2218	−0.0259	4.20 × 10−1	0.0111
Neuroticism	0.0539	4.79 × 10−19	0.3026	0.0055	6.82 × 10−1	0.0029

Abbreviations: GHQ, General Health Questionnaire; MDD, major depressive disorder; PHQ, Patient Health Questionnaire; PRS, polygenic risk score; SCZ, schizophrenia; SFHS, Scottish Family Health Study.

R² represents estimate of variance in trait explained by polygene score in percentage.

Significant interactions are highlighted in bold.