Stockholm district court sentenced 38-year-old Martin Trenneborg to ten years in prison in February for kidnapping his victim, but cleared him of aggravated rape.
On Thursday the Svea Court of Appeal shortened his sentence to eight years.
“The Court of Appeal found that there are also mitigating factors, such as the (doctor's) psychological disorder,” the judges explained in a statement.
Trenneborg, a general practitioner, had claimed to be depressed and suffering from suicidal thoughts.
The appeal court upheld the decision to order the defendant to pay his victim 80,000 kronor ($21,200) in damages to the victim.
Described in the media as “Sweden's Fritzl” – a reference to the Austrian father who held his daughter captive over 24 years – Trenneborg had been accused of drugging his victim by lacing strawberries and driving her to his country home while wearing a mask and fake number plates last autumn.
He had then been accused of locking the woman into what the prosecution has described as an above-ground “bunker” he had built in his yard, which resembles a garden shed from the outside.
The district court said in a statement announcing the earlier verdict that his purpose had been to keep the victim locked up to “force [her] to serve as girlfriend and future sex partner”.
“The doctor planned his crime meticulously and over a long period. In addition he put the victim at serious risk by drugging her and holding her in very uncomfortable conditions in this isolated bunker,” it said.
The identity of the victim has not been made public and her face was concealed during the trial.