Lucy Davis, known as Lucy Page, ‘deliberately jumped’ from Down End Road Bridge over the M27 near junction 11 for Fareham.
Sgt Wayne Voller, senior investigating officer, told how witnesses described Lucy, 32, from Fareham, falling from the bridge on to the trailer of an LGV being driven westbound by Grzegorz Ciupka.
The driver of another LGV, David Francis, told the inquest in Portsmouth he moved his cab so people who were ‘rubber-necking’ and ‘taking photos’ could not see.
Medics battled for an hour to save the mother-of-two after drivers rushed to help her.
The coroner’s court heard she would have died instantaneously.
Lucy had suffered with post-natal depression in 2004 after the birth of her first child and recovered after a few months, Sgt Voller said.
He added: ‘However the pressure of looking after the family, assisting with [her partner] Jon with admin side of business and being main carer for two relatives seems to bring a relapse in the latter part of 2015.’
The inquest heard on the day she died, December 15 last year, her partner Jon Cunningham knew ‘something was wrong from the moment she woke up’.
Asked in the morning if she was ok, Lucy told Jon: ‘No, not really,’ adding: ‘I don’t know what to do.’
Lucy had dropped her children off to school and finished buying their Christmas shopping and visited Jon at work before the incident.
He later heard a body had been found on the carriageway on the M27 and reported her missing to police and was visited by a family liaison officer who told him the tragic news.
Driver Janet Watts, was about to come off at Fareham travelling westbound and was in inside lane when she saw Lucy on the bridge just before 1.30pm.
She said she saw Lucy do a ‘deliberate jump’ and did not see anyone else on the bridge with her.
The inquest heard Lucy hit the trailer of the LGV before landing on the road between the inside lane and the middle lane.
A woman went to Lucy’s aid as well as Mr Francis, the driver of the LGV behind the LGV Lucy hit.
He said: ‘Morons were still driving past the body, rubber-necking, taking photographs.
‘I moved my truck. I positioned my cab so no-one could see the body so they’ve got nothing to look at while going past.’
He added other motorists continued to try to look.
Pathologist Dr Brett Lockyer’s report said she died from ‘traumatic head injury’ consistent with witnesses’ accounts.
He found anti-depressant medicine in her body but at an amount that showed she was not taking it.
Recording a narrative conclusion coroner David Horsley said: ‘Miss Davis took her own life whilst suffering from long-term severe depression.’
A BMW key fob was found at the scene and Lucy’s car was found near the bridge.
Mr Ciupka, a Polish national with a UK driving licence at the time, did not give evidence as he was back in Poland.
But the inquest heard even if he had seen Lucy it would probably have been too late to take evasive action.
How to get help
• Respond Portsmouth, the post-natal depression and anxiety for people in PO1 to PO6 areas: Call Julie Whitehead on 07833247634 or see respondportsmouth.co.uk
• Talking Change, for people over 16 registered with a GP in Portsmouth: (023) 9289 2928.
• iTalk for people over 16 registered with a GP in Fareham, Havant, Gosport and Fareham: (023) 8038 3920.