Mentally affecting Hitchcock film running (12)

I believe the answer is:

psychoactive

'mentally affecting' is the definition.
(affecting the brain)

'hitchcock film running' is the wordplay.
'hitchcock film' becomes 'psycho' (1960 film directed by Alfred Hitchcock).
'running' becomes 'active' (both can mean switched on).
'psycho'+'active'='PSYCHOACTIVE'

I've seen this clue in The Times.

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