The protective effect of a higher CD4 count against neuropsychiatric symptoms may also be linked to weight – lower CD4s are associated with lower weights.20 Lower CD4 counts are also associated with higher risk of TB,3 placing patients at a higher chance of being exposed to INH, either as part of TB treatment or prophylaxis, which would also increase their risk of EFV toxicity and neuropsychiatric symptoms. Here, CD4 is linked to tuberculosis.