Danielle Becker Friedland's family join search for the missing California mom who checked into flight home following six weeks at a Houston mental health clinic but then vanished - as distraught husband says 'we won't give up'

The distraught husband of a California woman who went missing after checking out of a mental health clinic in Texas says family and friends have joined the search after she was spotted in downtown Houston. 

Danielle Becker Friedland, 36, from the Bay Area city of Piedmont, checked her luggage onto her flight at Houston airport the day before Thanksgiving, left behind her phone and credit cards, then took a taxi and disappeared.

She had just been discharged after spending six weeks at the Menninger Clinic in Houston and was due to fly home to her husband Jordan - who is leading the search effort - and their two children, aged two and five.

'We have reason to believe she’s in the downtown area,' Jordan Friedland told the San Francisco Chronicle.

'We still have friends and family there looking and won’t give up until she’s found.'

Friends and family have flown to Houston to assist in the search. On Tuesday, the group searched along Buffalo Bayou near Memorial Park after receiving a tip.

On Wednesday they intend to resume searching the same area. 

'Dani has been going through an unexpected but ongoing mental health issue for several months now, and we just love and support her,' Jordan said to KTRK.

'Our kids miss her more than anything in the world. She's the most amazing mom in the world and the world is a better place with her and being a mom, friend, and community member.'

Authorities said Friedland had been diagnosed with depression, mood disorder psychosis, anxiety and obsessive-compulsive personality disorder.

She is approximately five foot two inches, weighs 100 pounds and has brown hair and brown eyes.

Friedland was last seen wearing a blue and orange-striped puffer jacket, dark pants, a black backpack and a beaded bracelet.

She left behind her luggage, phone and credit cards - taking with her a debit card and $160 in cash as she got a taxi.

Jordan travelled to Texas - his first time in the state - to try and help the search, telling local news station KHOU that there had been several unconfirmed sightings of her, but nothing certain.

'All the help we can get would be super helpful,' said Will True, a family friend.

'There's a lot of family and friends who have flown in from all over the country to find Dani and make sure she's safe.'

Jordan said they were focusing on homeless camps in the city, after she had referenced them, and were working with homeless outreach centers, churches and community groups.

'My biggest fear is just honestly Dani's safety,' he said.

'One of the scariest things for me is that Dani doesn't know Houston. She doesn't have friends or family here. She doesn't have her luggage, her credit cards, her phone and I just can't imagine how scary that must be.'

Jordan and Dani met 15 years ago, when they were both students at the University of Michigan.

'We have a two and a five-year-old and she's the best mom in the world and their world won't be the same without her,' he said.

The Menninger Clinic said they were saddened by the news, but not able to share any details of her condition.

'We are aware of the news coverage about this unfortunate event,' the clinic said in a statement.

'Because of patient confidentiality, we cannot confirm the status of any patient or provide any information without patient consent.

'We are deeply saddened by this situation and our hearts go out to the family. We all hope for her safe return.'

Anyone with information on her whereabout is asked to contact the Houston Police Department Missing Persons Divisions, Piedmont Police Department or the Friedland family at 832-378-8798.