Simon Jones, 30, has been sentenced to six years in jail after previously admitting manslaughter by gross negligence of his son Daniel.
Daniel's mother Emma Bradburn was also jailed for four years after the 34-year-old admitted allowing his death.
"It is one thing to risk your own health but quite another entirely to risk your son's," Justice Thirlwall of the Wolverhampton Crown Court said while sentencing the couple yesterday.
"He (Daniel) was utterly reliant upon you for every aspect of care in his life," Justice Thirlwall was quoted as saying by British news paper 'Daily Mirror'.
Wolverhampton crown court heard he slept in his parents' bed, where heroin paraphernalia was found. Thirty cannabis plants were found growing in the loft.