This is the 16000th most frequent Russian word.
психическое
"Психическое" means "mental" or "psychological" in English.
In this sentence, 'психическое' is used to describe 'здоровье' (health) and refers to aspects pertaining to the mind or psychological functioning, showing its adjectival nature.
Её психическое здоровье требует внимания.
Her mental health requires attention.
Here, 'психическое' qualifies 'напряжение' (tension) and indicates that the tension being referred to originates from or is associated with mental or psychological sources.
Психическое напряжение может привести к стрессу.
Mental tension can lead to stress.
In this context, 'психического' refers to 'развития' (development), discussing something related to the mental or psychological growth of individuals, illustrating its use in a nuanced description.